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81.
Abstract Toughness, as defined in ASTM D5801, is the work used to stretch a specimen until fracture, and is used to evaluate the ability of polymer modified asphalt (PMA) to resist deformation. Fracture elongations in PMA are usually longer than 10 cm. However, it is almost impossible for asphalt concrete, with or without PMA, to endure such large deformation before fracture. It is presumed that an effective elongation exists for more effective determination of toughness. Principle component analysis (PCA) and single regression analysis were used in this study to evaluate the correlation between physical tests of PMA, including toughness and performance tests of Stonic Mastic Asphalt (SMA). Meanwhile, performance tests, including resilient modulus tests, creep tests and indirect tensile tests, were conducted on SMA samples. According to the results form Principle Components Analysis (PCA), it was observed that only a common factor affects the performance tests. Regression analyses were used to find common factors from physical tests of PMA. Correlation coefficients between toughness and performance tests were found to be better than other physical tests. When toughness was calculated with effective elongation (6.5 cm), R 2 was 0.90. In our opinion, the desirable PMA should provide SMA enough work to resist the deformation while the deformation is still small. This result was also confirmed by observation of SEM and Rheological analysis. Modified toughness (calculated with effective elongation) considered as the common factor, is a simple method to evaluate the microstructure of PMA. Overall, modified toughness seems promising for use in evaluation of the effect of PMA on SMA. 相似文献
82.
Semi-active control is based on the use of the emerging concept of active control and passive control. The developed accumulator semi-active hydraulic damper (ASHD) is converted to interaction element (IE) of active interaction control (AIC). Systemic equations of motion, control law and control rulers of this proposed new AIC are studied in this research. A full-scale multiple degrees of freedom shaking table is tested to verify the energy dissipation of this proposed AIC, including test building without control, with passive control added involving various stiffness ratios and also with synchronic control added involving various stiffness ratios. Shock absorption of displacement can be up to 74–81% of that of the test structure with stiffness ratio = 2.3387 and 1.790 at 1st and 2nd floor under control of synchronous switch of this proposed AIC, respectively. No matter what the test structure added with various stiffeners at 1st and 2nd floor under synchronous control, test results of shock absorption ratio of acceleration show good seismic proof capability. In addition, base shear control effects of this proposed AIC method are higher than those of the test structure with various stiffeners added under passive control. These results show that AIC with stiffeners for structural control provides the characteristics of a stabilized structure under excitation of near-fault earthquake with velocity impulse action. 相似文献
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85.
Self‐Crack‐Filled Graphene Films by Metallic Nanoparticles for High‐Performance Graphene Heterojunction Solar Cells 下载免费PDF全文
86.
Li-Jane Shih Jia-Yu Wang Jing-Yao Jheng An-Ci Siao Yen-Yue Lin Yi-Wei Tsuei Yow-Chii Kuo Chih-Pin Chuu Yung-Hsi Kao 《International journal of molecular sciences》2020,21(23)
Prostate cancer (PCa) is a reproductive system cancer in elderly men. We investigated the effects of betel nut arecoline on the growth of normal and cancerous prostate cells. Normal RWPE-1 prostate epithelial cells, androgen-independent PC-3 PCa cells, and androgen-dependent LNCaP PCa cells were used. Arecoline inhibited their growth in dose- and time-dependent manners. Arecoline caused RWPE-1 and PC-3 cell cycle arrest in the G2/M phase and LNCaP cell arrest in the G0/G1 phase. In RWPE-1 cells, arecoline increased the expression of cyclin-dependent kinase (CDK)-1, p21, and cyclins B1 and D3, decreased the expression of CDK2, and had no effects on CDK4 and cyclin D1 expression. In PC-3 cells, arecoline decreased CDK1, CDK2, CDK4, p21, p27, and cyclin D1 and D3 protein expression and increased cyclin B1 protein expression. In LNCaP cells, arecoline decreased CDK2, CDK4, and cyclin D1 expression; increased p21, p27, and cyclin D3 expression; had no effects on CDK1 and cyclin B1 expression. The antioxidant N-acetylcysteine blocked the arecoline-induced increase in reactive oxygen species production, decreased cell viability, altered the cell cycle, and changed the cell cycle regulatory protein levels. Thus, arecoline oxidant exerts differential effects on the cell cycle through modulations of regulatory proteins. 相似文献
87.
Antioxidant activities of aqueous extracts of selected plants 总被引:1,自引:0,他引:1
The antioxidant properties of 25 edible tropical plants, expressed as Trolox equivalent antioxidant capacity (TEAC), were studied using DPPH (1,1-diphenyl-2-picrylhydrazyl free radical) scavenging and reducing ferric ion antioxidant potential (FRAP) assays. Their cupric ion chelating activities (CCA) and total polyphenol contents (TPC) were also determined. A strong correlation between TEAC values obtained for the DPPH assay (TEACDPPH) and those for the FRAP assay (TEACFRAP) implied that compounds in the extracts were capable of scavenging the DPPH free radical and reducing ferric ions. A satisfactory correlation of TPC with TEACDPPH and TEACFRAP suggested that polyphenols in the extracts were partly responsible for the antioxidant activities while its correlation with CCA was poor, indicating that polyphenols might not be the main cupric ion chelators. Principal component analysis (PCA) indicated that TEACDPPH, TEACFRAP and TPC contributed to the total variation in the antioxidant activities of the plants. 相似文献
88.
Yu‐Hao Chan Yushan‐Sophie Chang Yun‐Dun Shen Tzu‐Sen Yang Shih‐Fu Ou Ya‐Ju Hsu Mao‐Suan Huang Keng‐Liang Ou 《International Journal of Applied Ceramic Technology》2015,12(1):192-198
A bicalcium phosphate (BCP) bioceramic comprising α‐tricalcium phosphate (α‐TCP) and hydroxyapatite (HA) was prepared by a two‐step sintering. The microstructure of the BCP bioceramic was investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X‐ray diffraction. The in vitro osteoinductivity was evaluated by culturing MG63 osteoblast‐like cells on the BCP bioceramic. Results showed that the BCP bioceramic comprising α‐TCP and HA in a moderate ratio possessed a hardness of 93.7 Hv. The cells spread faster on the BCP bioceramic than those on the commercial HA. It suggested that the BCP bioceramic can enhance osteoinductivity in vivo. 相似文献
89.
Modularization strategy for syngas generation in chemical looping methane reforming systems with CO2 as feedstock 下载免费PDF全文
Peter Sandvik Fanhe Kong Yitao Zhang Abbey Empfield Liang‐Shih Fan 《American Institute of Chemical Engineers》2017,63(8):3343-3360
This study considers a CO2 feedstock in conventional methane reforming processes and metal oxide lattice oxygen based chemical looping reforming. Lattice oxygen from iron‐titanium composite metal oxide provides the most efficient co‐utilization of CO2 with CH4. A modularization chemical looping strategy is developed to further improve process efficiencies using a thermodynamic rationale. Modularization leverages the ability of two or more reactors operating in parallel to produce a higher quality syngas than a single reactor operating alone while offering a direct solution to scale up of multiple parallel reactor processes. Experiments conducted validate the thermodynamic simulation results. Simulation and experimental results ascertain that a cocurrent moving bed in a modularization system can operate under CO2 neutral or negative conditions. The results for a modularization process system for 7950 m3 per day (50,000 barrels per day) of liquid fuel indicate a ~23% reduction of natural gas usage over baseline‐case. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3343–3360, 2017 相似文献
90.
Feng-Yi Chou Chao-Ming Shih Meng-Chao Tsai Wen-Yen Chiu Shingjiang Jessie Lue 《Polymer》2012,53(14):2839-2846
This paper reports a novel method to synthesize magnetic, stimuli-sensitive latex nanoparticles made with magnetite/poly(N-isopropylacrylamide-co-acrylic acid) (Fe3O4/P(NIPAAm-co-AAc)). To form a stabilized suspended core, iron oxide (Fe3O4) was functionalized with AAc such that further polymerization with NIPAAm and AAc monomers could occur. The P(NIPAAm-co-AAc) shell layer exhibited thermosensitive properties. The inclusion of Fe3O4 into the latex nanoparticles was confirmed using transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction spectroscopy, thermogravimetric analyzer (TGA), and superconducting quantum interference device magnetometer. The NIP–(AAc2.6–Fe) latex nanoparticles contained 2.25% Fe3O4 (by weight), as determined by TGA analysis. The particle diameters measured approximately 160–240 nm with a lower critical solution temperature of 35 °C. These novel magnetic stimuli-responsive latex nanoparticles have potential applications in numerous fields, such as catalyst supports, protein immobilization, cancer therapy, target drug delivery systems, and other biomedical applications. 相似文献