A critical review of slag and fly-ash based geopolymer concrete

Tülin Akçaoğlu,Beste Çubukçuoğlu,Ashraf Awad 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.24 No.5

Today, concrete remains the most important, durable, and reliable material that has been used in the construction sector, making it the most commonly used material after water. However, cement continues to exert many negative effects on the environment, including the production of carbon dioxide (CO2), which pollutes the atmosphere. Cement production is costly, and it also consumes energy and natural non- renewable resources, which are critical for sustainability. These factors represent the motivation for researchers to examine the various alternatives that can reduce the effects on the environment, natural resources, and energy consumption and enhance the mechanical properties of concrete. Geopolymer is one alternative that has been investigated; this can be produced using aluminosilicate materials such as low calcium (class F) FA, Ultra-Fine GGBS, and high calcium FA (class C, which are available worldwide as industrial, agricultural byproducts.). It has a high percentage of silica and alumina, which react with alkaline solution (activators). Aluminosilicate gel, which forms as a result of this reaction, is an effective binding material for the concrete. This paper presents an up-to-date review regarding the important engineering properties of geopolymer formed by FA and slag binders; the findings demonstrate that this type of geopolymer could be an adequate alternative to ordinary Portland cement (OPC). Due to the significant positive mechanical properties of slag-FA geopolymer cements and their positive effects on the environment, it represents a material that could potentially be used in the construction industry.

Effective and Secure Access Control for Multi-Authority Cloud Storage Systems

Lin Xin,Xingming Sun,Zhangjie Fu,Liang-Ao Zhang,Jie Xi 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.2

Ciphertext-Policy Attribute-Based Encryption (CP-ABE) is a promising cryptographic tool to implement access control for secure cloud storage systems. However, most existing access control schemes based on CP-ABE for the multi-authority cloud storage systems rely on a fully trusted global certificate authority. It is just an ideal assumption while there never exists a fully trusted global certificate authority in reality. In this paper, we construct a system with multiple certificate authorities (CA). The parameters of those CAs could be verified when an authority suspects the messages received from the correlative certificate authority. Besides, we construct a verifiable secret sharing (VSS) scheme to realize the decentralization of the certificate authority in our scheme. The scheme adopts the Pedersen commitment in combination with the properties of bilinear-pairs on elliptic curve and bilinear Diffie-Hellman problem. The analysis shows that our scheme is highly efficient, authentic and provably secure under the security model. Our scheme simultaneously supports efficient attribute revocation.

Exploring the Fuel Economy Potential of ISG Hybrid Electric Vehicles through Dynamic Programming

Guoqiang Ao,Hu Zhong,Jiaxi Qiang,Lin Yang,Bin Zhuo 한국자동차공학회 2007 International journal of automotive technology Vol.8 No.6

Hybrid electric vehicles (HEV) combined with more than one power sources have great potential to improve fuel economy and reduce pollutant emissions. The Integrated Starter Generator (ISG) HEV researched in this paper is a two energy sources vehicle, with a conventional internal combustion engine (ICE) and an energy storage system (batteries). In order to investigate the potential of diesel engine hybrid electric vehicles in fuel economy improvement and emissions reduction, a Dynamic Programming (DP) based supervisory controller is developed to allocate the power requirement between ICE and batteries with the objective of minimizing a weighted cost function over given drive cycles. A fuel-economy-only case and a fuel & emissions case can be achieved by changing specific weighting factors. The simulation results of the fuel-economy-only case show that there is a 45.1% fuel saving potential for this ISG HEV compared to a conventional transit bus. The test results present a 39.6% improvement in fuel economy which validates the simulation results. Compared to the fuel-economy-only case, the fuel & emissions case further reduces the pollutant emissions at a cost of 3.2% and 4.5% of fuel consumption with respect to the simulation and test result respectively.

Early gut microbiota in very low and extremely low birth weight preterm infants with feeding intolerance: a prospective case-control study

Liu Ling,Ao Dang,Cai Xiangsheng,Huang Peiyi,Cai Nali,Lin Shaozhu,Wu Benqing 한국미생물학회 2022 The journal of microbiology Vol.60 No.10

The potential role of the gut microbiota in the pathogenesis of feeding intolerance (FI) remains unclear. Understanding the role of the gut microbiota could provide a new avenue for microbiota-targeted therapeutics. This study aimed to explore the associations between aberrant gut microbiota and FI in very low or extremely low birth weight (VLBW/ELBW) preterm infants. In this observational case-control study, VLBW/ ELBW infants were divided into two groups: FI group and feeding tolerance (FT) group. 16S rRNA gene sequencing was performed to analyze the gut microbial diversity and composition of the infants. The differences in the gut microbiota of the two groups were compared. In total, 165 stool samples were obtained from 44 infants, among which, 31 developed FI and 13 served as controls. Alpha diversity was the highest in the meconium samples of the two groups. LEfSe analysis revealed that the abundances of Peptostreptococcaceae, Clostridiales and Clostridia in the FT group were significantly higher than in the FI group. At the phylum level, the FI group was dominated by Proteobacteria, and the FT group was dominated by Firmicutes. The meconium samples of the FI group had higher proportions of γ-proteobacteria and Escherichia-Shigella and a lower proportion of Bacteroides compared with the FT group. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated that aberrant gut bacteria in the FI group were strongly associated with dysregulation of C5-Brancheddibasic- acid-metabolism, protein kinases, and sporulation. These findings reveal candidate microbial markers to prevent FI. Increased relative abundances of γ-proteobacteria and Escherichia-Shigella and decreased abundance of Bacteroides in meconium were associated with an increased risk of FI, while Peptostreptococcaceae, Clostridiales and Clostridia reduced the risk of FI in VLBW/ELBW infants.

P-value significance level test for high-performance steel fiber concrete (HPSFC)

Abdulhameed U. Abubakar,Tülin Akçaoğlu and Khaled Marar 사단법인 한국계산역학회 2018 Computers and Concrete, An International Journal Vol.21 No.5

Statistical analysis has found useful application in the design of experiments (DOE) especially optimization of concrete ingredients however, to be able to apply the concept properly using computer aided applications there has to be an upper and lower limits of responses fed to the system. In this study, the production of high-performance steel fiber concrete (HPSFC) at five different fiber addition levels by volume with two aspect ratios of 60 and 83 were studied under two curing methods completely dry cured (DC) and moist cured (MC) conditions. In other words, this study was carried out for those limits based on material properties available in North Cyprus. Specimens utilized were cubes 100 mm size casted and cured for 28 days and tested for compressive strength. Minitab 18 statistical software was utilized for the analysis of results at a 5 per cent level of significance. Experimentally, it was observed that, there was fluctuation in compressive strength results for the two aspect ratios and curing regimes. On the other hand P-value hypothesis evaluation of the response showed that at the stated level of significance, there was a statistically significant difference between dry and moist curing conditions. Upper and lower limit values were proposed for the response to be utilized in DOE for future studies based on these material properties. It was also suggested that for a narrow confidence interval and accuracy of the system, future study should increase the sample size.

Improved Meta-learning Neural Network for the Prediction of the Historical Reinforced Concrete Bond–Slip Model Using Few Test Specimens

Chengwen Zhang,Qing Chun,Ao Sun,Yijie Lin,HaoYu Wang 한국콘크리트학회 2022 International Journal of Concrete Structures and M Vol.16 No.5

The bond–slip model plays an important role in the structural analysis of reinforced concrete structures. However, many factors affect the bond–slip behavior, which means that a large number of tests are required to establish an accurate bond–slip model. This paper aims to establish a data-driven method for the prediction of the bond–slip model of historical reinforced concrete with few test specimens and many features. Therefore, a new Mahalanobis-Meta-learning Net algorithm was proposed, which can be used to solve the implicit regression problem in few-shot learning. Compared with the existing algorithms, the Mahalanobis-Meta-learning Net achieves fast convergence, accurate prediction and good generalization without performing a large number of tests. The algorithm was applied to the prediction task of the bond–slip model of square rebar-reinforced concrete. First, the first large pretraining database for the bond–slip model, BondSlipNet, was established containing 558 samples from the existing literature. The BondSlipNet database can be used to provide a priori knowledge for learning. Then, another database, named SRRC-Net, was obtained by 16 groups of pull-out tests with square rebar. The SRRC-Net database can be used to provide the posteriori knowledge. Finally, based on the databases, the algorithm not only successfully predicted the bond–slip model of square rebar-reinforced concrete, but also that of the other 23 types of reinforced concrete. The research results can provide a scientific basis for the conservation of square rebar-reinforced concrete structures and can contribute to the bond–slip model prediction of the other types of reinforced concrete structures.

New Isoxys arthropod from Cambrian (Series 2, Stage 3) Qingjiang Biota, South China

Jiaxin Ma,Cong Liu,Weiliang Lin,Ao Sun,Yu Wu,Dongjing Fu 대한지질학회 2017 대한지질학회 학술대회 Vol.2017 No.10

Distinct sets of lysosomal genes define synucleinopathy and tauopathy

( Kyu Won Oh ),( Dong-kyu Kim ),( Ao-lin Hsu ),( Seung-jae Lee ) 생화학분자생물학회 2023 BMB Reports Vol.56 No.12

Neurodegenerative diseases are characterized by distinct protein aggregates, such as those of α-synuclein and tau. Lysosomal defect is a key contributor to the accumulation and propagation of aberrant protein aggregates in these diseases. The discoveries of common proteinopathies in multiple forms of lysosomal storage diseases (LSDs) and the identification of some LSD genes as susceptible genes for those proteinopathies suggest causative links between LSDs and the proteinopathies. The present study hypothesized that defects in lysosomal genes will differentially affect the propagation of α-synuclein and tau proteins, thereby determining the progression of a specific proteinopathy. We established an imaging-based high-contents screening (HCS) system in Caenorhabditis elegans (C. elegans) model, by which the propagation of α-synuclein or tau is measured by fluorescence intensity. Using this system, we performed RNA interference (RNAi) screening to induce a wide range of lysosomal malfunction through knock down of 79 LSD genes, and to obtain the candidate genes with significant change in protein propagation. While some LSD genes commonly affected both α-synuclein and tau propagation, our study identified the distinct sets of LSD genes that differentially regulate the propagation of either α-synuclein or tau. The specificity and efficacy of these LSD genes were retained in the disease-related phenotypes, such as pharyngeal pumping behavior and life span. This study suggests that distinct lysosomal genes differentially regulate the propagation of α-synuclein and tau, and offer a steppingstone to understanding disease specificity. [BMB Reports 2023; 56(12): 657-662]

Effects of different culture systems on the culture of buffalo (Bubalus bubalis) spermatogonia stem cell-like cells in vitro

Ting-Ting Li,Shuang-Shuang Geng,Hui-Yan Xu,Ao-Lin Luo,Peng-Wei Zhao,Huan Yang,Xing-Wei Liang,Yang-Qing Lu,Xiao-Gan Yang,Ke-Huan Lu 대한수의학회 2020 Journal of Veterinary Science Vol.21 No.1

Currently, the systems for culturing buffalo spermatogonial stem cells (SSCs) in vitro are varied, and their effects are still inconclusive. In this study, we compared the effects of culture systems with undefined (foetal bovine serum) and defined (KnockOut Serum Replacement) materials on the in vitro culture of buffalo SSC-like cells. Significantly more DDX4- and UCHL1-positive cells (cultured for 2 days at passage 2) were observed in the defined materials culture system than in the undefined materials system (p < 0.01), and these cells were maintained for a longer period than those in the culture system with undefined materials (10 days vs. 6 days). Furthermore, NANOS2 (p < 0.05), DDX4 (p < 0.01) and UCHL1 (p < 0.05) were expressed at significantly higher levels in the culture system with defined materials than in that with undefined materials. Induction with retinoic acid was used to verify that the cultured cells maintained SSC characteristics, revealing an SCP3+ subset in the cells cultured in the defined materials system. The expression levels of Stra8 (p < 0.05) and Rec8 (p < 0.01) were significantly increased, and the expression levels of ZBTB16 (p < 0.01) and DDX4 (p < 0.05) were significantly decreased. These findings provided a clearer research platform for exploring the mechanism of buffalo SSCs in vitro.

S100A4 Gene is Crucial for Methionine-Choline-Deficient Diet-Induced Non-Alcoholic Fatty Liver Disease in Mice

Yin-Hua Zhang,De-Ping Ding,De-Qiang Ma,Juan Li,Lin-Li Chen,Kang-Jian Ao,You-You Tian 연세대학교의과대학 2018 Yonsei medical journal Vol.59 No.9

Purpose: To explore the influence of S100 calcium binding protein A4 (S100A4) knockout (KO) on methionine-choline-deficient(MCD) diet-induced non-alcoholic fatty liver disease (NAFLD) in mice. Materials and Methods: S100A4 KO mice (n=20) and their wild-type (WT) counterparts (n=20) were randomly divided into KO/MCD, Ko/methionine-choline-sufficient (MCS), WT/MCD, and WT/MCS groups. After 8 weeks of feeding, blood lipid and liverfunction-related indexes were measured. HE, Oil Red O, and Masson stainings were used to observe the changes of liver histopathology. Additionally, expressions of S100A4 and proinflammatory and profibrogenic cytokines were detected by qRT-PCR andWestern blot, while hepatocyte apoptosis was revealed by TUNEL staining. Results: Serum levels of aminotransferase, aspartate aminotransferase, triglyceride, and total cholesterol in mice were increasedafter 8-week MCD feeding, and hepatocytes performed varying balloon-like changes with increased inflammatory cell infiltrationand collagen fibers; however, these effects were improved in mice of KO/MCD group. Meanwhile, total NAFLD activity scoresand fibrosis were lower compared to WT+MCD group. Compared to WT/MCS group, S100A4 expression in liver tissue of WT/MCD group was enhanced. The expression of proinflammatory (TNF-α, IL-1β, IL-6) and profibrogenic cytokines (TGF-β1, COL1A1,α-SMA) in MCD-induced NAFLD mice were increased, as well as apoptotic index (AI). For MCD group, the expressions ofproinflammatory and profibrogenic cytokines and AI in KO mice were lower than those of WT mice. Conclusion: S100A4 was detected to be upregulated in NAFLD, while S100A4 KO alleviated liver fibrosis and inflammation, inaddition to inhibiting hepatocyte apoptosis.