Seismic Performance of Desert-sand Autoclaved Aerated Concrete Block Wall Constrained by Precast Integral Construction Column

Yushan Wang,Wenxing Zhu,Jianjun Cheng 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.9

Considering the structural types and construction techniques used in common residential buildings in Xinjiang, the paper proposes a novel masonry structure, i.e., desert-sand AAC blocks constrained by a precast integral construction column. In order to study the seismic performance of the structure, five wall specimens with different constraints are designed and fabricated and further compared and analyzed in terms of failure mode, hysteretic performance, energy dissipation capacity, ductility, stiffness degradation, and other performance indexes. It has been determined from the results that under horizontal low-cycle repeated loading, the main failure cracks of the desert-sand AAC block wall constrained by the precast integral construction column are intersecting oblique cracks, and the cracks in wall failure penetrate along concrete blocks. The stiffness degradation rate of the wall constrained by the water-resistant gypsum construction column gradually decreases with increasing vertical compressive stress. The wall constrained by the water-resistant gypsum construction column with arranged steel bars has a desirable ductility. Under the same vertical compressive stress, the wall constrained by the water-resistant gypsum precast construction column with arranged steel bars has a significant energy dissipation capacity from cracking to the ultimate state. (4) A restoring force model is built for desert-sand AAC block walls constrained by the precast integral construction column using a three-fold line model, offering technical support for the elastoplastic seismic analysis of structures.

A COST-EFFECTIVE PROCESS FOR SYNTHESIZING MAGNESIUM BORATE NANORODS AND ITS MECHANICAL PROPERTY FOR REINFORCED NYLON-6 COMPOSITES

LICONG WANG,YUAN LIU,YUSHAN ZHANG,DAN CHEN,YUQI WANG,ZELIANG DONG,YONGCHAO LU,XIPING HUANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.7

Magnesium borate (Mg 2 B 2 O 5 Þ nanorods were synthesized by a two-step process, includingsolution-chemical technology and a ternary-°ux method, using concentrated seawater and H 3 BO 3as raw materials. X-ray di®raction (XRD) showed that the sample had triclinic structure. Scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HR-TEM) indicated that it consisted of rod-like particles with an average diameter of 100 – 150 nmand length over 5 ? m. Di®erential thermal analysis (DTA) con¯rmed that the melting point ofthe ternary-°ux and the formation temperature of Mg 2 B 2 O 5 were lower than single-°ux process. The formation of Mg 2 B 2 O 5 nanorods was more e±cient by ternary-°ux than single-°ux. Me-chanical property of Mg 2 B 2 O 5 nanorods reinforced Nylon-6 composites showed that KH550 wasthe optimal coupling agent and made the strength of the composites to be improved to differentdegrees.

한국산 장류콩 종자 렉틴의 생화학적 특성

王玉珊(Yushan Wang),노광수(Kwang Soo Roh) 한국생물공학회 2009 KSBB Journal Vol.24 No.2

한국산 장류콩 종자로부터 최종적으로 Sephadex G-100 상에서 분리한 lectin의 분자량, 적혈구 응집력, 온도, 열 안정성, 및 pH의 생화학적 특성을 조사하였다. 분리된 lectin을 SDS-PAGE한 결과, 분자량이 32 kDa와 22 kDa인 2개의 band가 나타났으며, Native PAGE에 의해서 108 kDa의 tetramer임을 알 수 있었다. Lectin은 trypsin을 처리한 사람의 A, B, AB, O 혈액과 쥐 혈액에서 혈구응집 반응이 일어나지 않았으나 토끼에서는 응집 반응이 일어났으며, trypsin 을 처리하지 않은 모든 혈액에서는 응집반응이 일어나지 않았다. 이 lectin은 최적온도가 20-50℃이며, 10-60℃에서 열 안정성을 보였다. 최적 pH는 7.2로서 6.2 이하와 8.0 이상에서는 활성이 상실되었다. Lectin was finally isolated on Sephadex G-100 from Korean soybean cultivars developed for soy source and investigated its some biochemical properties. Native PAGE pattern of this lectin revealed a molecular weight of 108 kDa as tetramer. The molecular weight of this lectin isolated as double protein band by SDS-PAGE was calculated to be 32 and 22 kDa from the relative mobilities compared with those of the standard proteins. Among the tested red blood cell, the isolated lectin agglutinated rabbit red blood cell treated with trypsin, but did not agglutinated human red blood cells (A, B, AB, O), rat, and untreated rabbit red blood cell. The optimal temperature and thermal stability of isolated lectin was at 20-50℃ and 10-60℃, respectively. This lectin was stable at 7.2, and showed complete loss in its activity below pH 6.2 and above pH 8.0.

A Fast and Accurate Algorithm for Detecting Community Structure in Social Networks

Junheng Huang,Yushan Sun,Yang Liu,Bailing Wang 보안공학연구지원센터(IJUNESST) 2015 International Journal of u- and e- Service, Scienc Vol.8 No.1

Studies of community structure and evolution in large social networks require fast and accurate algorithms for community detection. Among the existing algorithms for community detection, the label propagation algorithm (LPA) and the Newman modularity Q algorithm (NMA) have been widely used and studied in the community detection in large social networks, since the LPA has the advantages of near-linear running time, easy implementation and without requiring parameters, and the NMA is a relatively fast algorithm and has a clear metrics to measure community structure. However, the LPA has the shortcomings that the result of the community detection is instable and has a low quality. At the same time, disadvantages of the NMA are that it bases its decisions on purely local information about individual communities and gets the local optimal solution. In this paper, combined with these two algorithms, we propose a new community detection algorithm (LP-NMA), which extends the above two algorithms (the LPA and the NMA is a special case of the new algorithm respectively). The new algorithm not only retains the advantages of these two algorithms, but also has improved the stability and quality of community detection. Experiments on real social networks have proved that this method is better than the original LPA and NMA.

Video-Induced Visit to a Destination: The Psychological Mechanism and the Role of Video Sharing Sources

Wang, Erin Yirun,Luo, Sara Yushan,Fong, Lawrence Hoc Nang,Law, Rob Smart Tourism Research Center 2021 Journal of smart tourism Vol.1 No.3

Promotional videos have been increasingly adopted in social media marketing. Given that video production incurs high costs, evaluating the effectiveness of promotional videos is necessary. This research examines the effect of promotional video on visit intention through affective and cognitive destination images, respectively. Furthermore, grounded in the theoretical reasoning of social ties and persuasive intent, the effects of promotional videos disseminated by different sources (i.e., unknown users, friends, and marketers) are compared. Two experimental studies were carried out with 200 participants in Study 1 and 243 participants in Study 2. Study 1 revealed that the presence of promotional video induces visit intention through affective and cognitive destination images. Study 2 found that promotional videos disseminated by friends (versus unknown users) are more effective to induce visit intention because of positive cognitive destination image, while the video effects are indifferent between marketers and users. Meaningful implications are provided for destination marketers.

Evaluation of Curtain Grouting Efficiency by Cloud Model - based Fuzzy Comprehensive Evaluation Method

Yushan Zhu,Xiaoling Wang,Shaohui Deng,Mengqi Zhao,Xuefei Ao 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.7

Because of the concealment and uncertainty of dam foundation grouting, the accurate evaluation of the quality of grouting construction is a major concern. Most of the previous studies pertaining to the assessment of grouting efficiency only take a single factor into account, and only a few efforts have been devoted to the comprehensive evaluation of grouting efficiency, which fail to consider the fuzziness problems caused by the complex relationships among indicators as well as the randomness problems caused by subjective consciousness. Therefore, the curtain grouting efficiency evaluation method considering the uncertainty in evaluation process is proposed which includes three main parts: 1) Based on conventional evaluation indicators of grouting efficiency, where groutability is introduced as a new indicator; 2) a fuzzy comprehensive evaluation method based on cloud model is developed, by which the fuzziness and randomness in assessment are organically combined; and 3) the fuzzy entropy was calculated for indicating the complexity of grouting efficiency level. Then, the proposed method is used to assess efficiency of the curtain grouting for a hydropower station in China, and compared with three other methods. The outcomes display the consistency, representativeness, robustness and superiority of this evaluation method, which make the evaluation results more scientific and objective.

A Topological Mapping Grinding Strategy for Structured Groove Surface with the Wire-Wound Grinding Wheel

Lyu Yushan,Wang Guoxun,Li Xingshan,Tang Chengzhi 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.7

The structured groove surface is one of the important surfaces in the field of reducing fluid drag or contact friction. The research on the manufacturing technology of the structured groove drag or friction reduction surface has important theoretical significance and practical value for the engineering application of the theoretical research results of the drag or friction reduction of the surface. In order to grind structured groove surface, a new topological mapping grinding strategy for structured groove surfaces is innovated based on topology. In order to verify the feasibility of this strategy, the topological features of the structured groove surface were firstly analyzed and modeled, and the topological feature parameters were extracted. Based on the feature parameters, the homeomorphic mapping equation of the grinding process is established, and according to the established equation, a circular arc-shaped helical structure grinding wheel with convex properties is designed, and the effect of grinding parameters on the structured groove surface is simulated and analyzed. Finally, a wire-wound structured grinding wheel with a diamond wire saw as the abrasive carrier was manufactured, and the experimental investigation of grinding structured groove surface was carried out. The results show that the innovative topology grinding strategy is feasible; the grinding wheel designed based on the topological features of the structured groove surface can realize the topological mapping grinding of the structured groove surface; the change of grinding parameters can lead to the change of the geometric size of the groove, but the topological properties remain unchanged.

Effect of storage time and the level of formic acid on fermentation characteristics, epiphytic microflora, carbohydrate components and in vitro digestibility of rice straw silage

Zhao Jie,Wang Siran,Dong Zhihao,Li Junfeng,Jia Yushan,Shao Tao 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.6

Objective: The study aimed to evaluate the effect of storage time and formic acid (FA) on fermentation characteristics, epiphytic microflora, carbohydrate components and in vitro digestibility of rice straw silage. Methods: Fresh rice straw was ensiled with four levels of FA (0%, 0.2%, 0.4%, and 0.6% of fresh weight) for 3, 6, 9, 15, 30, and 60 d. At each time point, the silos were opened and sampled for chemical and microbial analyses. Meanwhile, the fresh and 60-d ensiled rice straw were further subjected to in vitro analyses. Results: The results showed that 0.2% and 0.6% FA both produced well-preserved silages with low pH value and undetected butyric acid, whereas it was converse for 0.4% FA. The populations of enterobacteria, yeasts, moulds and aerobic bacteria were suppressed by 0.2% and 0.6% FA, resulting in lower dry matter loss, ammonia nitrogen and ethanol content (p<0.05). The increase of FA linearly (p<0.001) decreased neutral detergent fibre and hemicellulose, linearly (p<0.001) increased residual water soluble carbohydrate, glucose, fructose and xylose. The in vitro gas production of rice straw was decreased by ensilage but the initial gas production rate was increased, and further improved by FA application (p<0.05). No obvious difference of FA application on in vitro digestibility of dry matter, neutral detergent fibre, and acid detergent fibre was observed (p>0.05). Conclusion: The 0.2% FA application level promoted lactic acid fermentation while 0.6% FA restricted all microbial fermentation of rice straw silages. Rice straw ensiled with 0.2% FA or 0.6% FA improved its nutrient preservation without affecting digestion, with the 0.6% FA level best. Objective: The study aimed to evaluate the effect of storage time and formic acid (FA) on fermentation characteristics, epiphytic microflora, carbohydrate components and <i>in vitro</i> digestibility of rice straw silage.Methods: Fresh rice straw was ensiled with four levels of FA (0%, 0.2%, 0.4%, and 0.6% of fresh weight) for 3, 6, 9, 15, 30, and 60 d. At each time point, the silos were opened and sampled for chemical and microbial analyses. Meanwhile, the fresh and 60-d ensiled rice straw were further subjected to <i>in vitro</i> analyses.Results: The results showed that 0.2% and 0.6% FA both produced well-preserved silages with low pH value and undetected butyric acid, whereas it was converse for 0.4% FA. The populations of enterobacteria, yeasts, moulds and aerobic bacteria were suppressed by 0.2% and 0.6% FA, resulting in lower dry matter loss, ammonia nitrogen and ethanol content (p<0.05). The increase of FA linearly (p<0.001) decreased neutral detergent fibre and hemicellulose, linearly (p<0.001) increased residual water soluble carbohydrate, glucose, fructose and xylose. The <i>in vitro</i> gas production of rice straw was decreased by ensilage but the initial gas production rate was increased, and further improved by FA application (p<0.05). No obvious difference of FA application on <i>in vitro</i> digestibility of dry matter, neutral detergent fibre, and acid detergent fibre was observed (p>0.05).Conclusion: The 0.2% FA application level promoted lactic acid fermentation while 0.6% FA restricted all microbial fermentation of rice straw silages. Rice straw ensiled with 0.2% FA or 0.6% FA improved its nutrient preservation without affecting digestion, with the 0.6% FA level best.

Experimental investigation on grinding temperature of Ti-6Al-4V using biomimetic engineered grinding wheel

Haiyue Yu,Yushan Lyu,Jun Wang 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.6 No.2

Ti–6Al–4 V is classed as difficult-to-process material due to its lower thermal conductivity and specific heat. Furthermore, the contact area between grinding wheel and workpiece is larger than other processing methods generally. Therefore, the process of grinding Ti–6Al–4 V is easier to generate high temperature. Most grinding fluid are used and wasted in usual grinding process to dissipate heat. Some green technologies are used to solve this issue in the aspect of fluid supply usually. This paper is to reduce grinding temperature from the other way–grinding wheel. In order to lower grinding temperature without increasing liquid coolant flow, an innovative grinding wheel inspired by phyllotaxis theory was manufactured using electroplating method and photo etching technique. Some contrastive experiments of grinding temperature for the alloy were conducted with the measured method of artificial thermocouple. The change rule of grinding temperature with the change of grinding parameters was found. The results shown that the grinding temperature of Ti–6Al–4 V with the biomimetic engineered grinding wheel was always the lowest in experiments due to less heat generation and more heat dissipation. Finally, the grinding temperature of the biomimetic engineered grinding wheels with different phyllotactic coefficient were investigated and discussed. A new point of view to lower grinding temperature was present and proved in this paper, which may become an important green technology for grinding in future.

Probabilistic Risk Assessment of RCC Dam Considering Grey-Stochastic-Fuzzy Uncertainty

Wenlong Chen,Xiaoling Wang,Minghui Liu,Yushan Zhu,Shaohui Deng 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.11

Greyness, randomness and fuzziness are three inseparable uncertainty factors influencing the safety of a roller compacted concrete dam (RCC dam), which can be regarded as a system reliability problem associated with multiple failure modes. Aiming at the current probabilistic risk analysis of RCC dams, most of the studies limited to single failure mode and single uncertainty. A probabilistic risk assessment method for dam under Grey-Stochastic-Fuzzy (GSF) uncertainty is proposed to consider the randomness and greyness of parameters and the fuzziness of the failure criteria. First, the fault tree model of an RCC dam is established based on Fault Tree Analysis (FTA). Then, bootstrap repeated sampling is embedded into grey system theory to quantify the grey properties of stochastic variables. The Latin Hypercube Sampling (LHS) function is improved to compensate for the inability of describing the fuzzy failure criteria. Finally, considering the correlated multiple failure modes, the proposed method is applied to analyze the parameter sensitivity and failure probability of the LDL dam in China. The results show that the proposed method is a high-efficiency, fastconvergence and more scientific method with reasonable outputs compared to common uncertainty probability analysis methods. The proposed method also provides an effective basis for the structural design and safety analysis of a concrete dam.