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Based on the Aggregate Imaging Measurement System (AIMS) and the Particle Flow Code in Two Dimensions (PFC2D), an algorithm for modeling two-dimensional virtual aggregates was proposed in this study. To develop the virtual particles precisely, the realistic shapes of the aggregates were captured by the AIMS firstly. The shape images were then processed, and the morphological characteristics of aggregates were quantified by the angularity index. By dividing the particle irregular shape into manydoi:10.3390/app8050738 fatcat:7xzjzxaynnb2rnrkf6rjz22zgq
more »... triangle areas and adjusting the positions of the generated balls via coordinate systems' conversion within PFC2D, the virtual particles could be reconstructed accurately. By calculating the mapping area, the gradations in two-dimensions could be determined. Controlled by two variables (µ_1 and µ_2), which were drawn from the uniform distribution (0, 1), the virtual particles forming the specimens could be developed with random sizes and angular shapes. In the end, the rebuilt model of the SMA-13 aggregate skeleton was verified by the virtual penetration tests. The results indicated that the proposed algorithm can not only model the realistic particle shape and gradations precisely, but also predict its mechanical behavior well. following shape acquisition, which is the basis to guarantee the results [7, 8] . The discrete-element method (DEM) was proposed by the Cundall  firstly, and then, a software program named Particle Flow Code (PFC) was developed to help the mechanical calculation of heterogeneous materials, which has been widely used in many fields    . As the basic calculation elements, the balls in the software (PFC2D, Itasca Consulting Group: Minneapolis, USA) are all round shaped without any angular shape, which is not consistent with the realistic particles in pavement construction. Therefore, prior to numerical simulation, it is important to rebuild the realistic particle shape, which will influence the simulation results obviously    . Many modeling methods have been proposed within PFC to characterize the shape features by some researchers. Zhang et al.  regarded the aggregate particles as hexahedrons, pentahedrons and tetrahedrons within PFC, respectively. Then, the equal-radius balls were arranged regularly within the particles and were defined as a rigid body. CPA (Computerized Particle Analysis) was utilized to help develop the virtual shape within PFC by Stahl and Konietzky  . The input index, known as the grain-shape coefficient, was used to redefine the particle contour. Then, numerical particles were reconstructed by filling the redefined area with balls. Huang  reconstructed 3D ballast particles with three images (top, side and front) of the particles with the help of the image processing technology. Similar methods can also be found in the works of Liu and You [19, 20] , Tutumluer et al.  and Dondi and Vignali    , as well. Most of the existing modeling methods can only model the shape roughly with excessive simplification. Although some virtual models were rebuilt precisely by X-ray scanning, the angular shape could not be quantified precisely      . Liu scanned the particles and rebuilt their virtual shapes according to the acquired images [30, 31] . In their studies, the stl-format file were developed, which can reflect the shapes of aggregates precisely. By the designed routine, the virtual particles in three dimensions were developed successfully with enough balls filled. However, their methods can only model the realistic shapes, but cannot evaluate the shape properties of mixtures by a specific index. Therefore, the simulation accuracy mainly depends on the samples' selection and cannot model the material heterogeneity well. Compared to X-ray scanning, the Aggregate Imaging Measurement System (AIMS) apparatus is a promising way for performing particle shape modeling and has been utilized gradually in material analyses  . It can capture the morphological characteristics of aggregates and quantifies the shape properties by some design indices such as the angularity index, texture index, size, and so on. However, this apparatus is mainly used for pavement skid resistance measurements nowadays    . More uses of it should be explored, especially combined with other technologies. The objective of this study is to propose an algorithm for the virtual aggregates' reconstitution based on the Discrete-Element Method (DEM). To achieve this, the AIMS apparatus with the image processing technology were utilized before the simulations. Then, an innovative method for developing the virtual particles and gradations was proposed precisely. In the end, based on the virtual penetration tests, the precision of the developed models was verified. The relevant issues include: capturing the shape image of particles by AIMS; processing the captured images and measuring their angularity index; modeling the virtual particles with different sizes and shapes; modeling the virtual gradations of specimens; developing the virtual penetration tests to predict and evaluate the performance of coarse aggregates. Image Preprocessing and Shape Measurement Prior to the virtual particles' reconstitution, several steps were performed that could provide the proposed algorithm with the fundamental data. Firstly, enough aggregate particles were selected and were scanned by the AIMS to obtain their shape image and the angularity index. The particles were put in the turntable of the AIMS and were rotated slowly to go through the scanning area. A digital camera above the particles was utilized to capture the image of the maximum section from the top side. Then, the original images of the particles were converted to the binary ones within the MATLAB routine as shown in Figure 1 . As shown, two forms of binary images were acquired via the image processing technology including the shape (Figure 1a ) and its contour (Figure 1b) .
Focused on the fatigue performance of the asphalt mortar, this study proposed an assessment model for fatigue damage evolution based on the continuum mechanics. From the perspective of the material scale rather than the macrostructure, the proposed damage model was set by concentrating on the stress-strain state of a tiny point which could characterize the material performance accurately. By the mechanical formula derivation and based on the four-point bending fatigue tests, the damagedoi:10.1155/2018/5904807 fatcat:h43wmgvv3nfwrnem6cqthz2mlq
more »... law was determined and then the proposed model was verified. Based on the finite element method (FEM), a commercial software named ABAQUS was utilized to develop the random mixtures consisting of coarse aggregates, mortar, and voids. Eventually, combined with the damage model and virtual simulation of bending tests, the factors influencing the fatigue resistance of the whole asphalt mixtures were analyzed further.
Based on the Particle Flow Code in Two dimensions (PFC2D), an algorithm for modeling the two-dimensional virtual asphalt mixture was proposed in this study. By combining the AIMS scanning technology (Aggregate Imaging Measurement System) with the designed stochastic algorithm, the virtual coarse aggregates could be generated rapidly and precisely. Different from the conventional methods, the contour shapes of the coarse aggregates were rebuilt only to balance the shape modeling precision anddoi:10.1155/2018/5180562 fatcat:wilkrd4pgnhu5ir4too6ohkmu4
more »... ulation efficiency. Then by distributing the coarse particles within container, virtual skeletons were formed firstly. An innovate algorithm was proposed afterwards to distinguish the external and internal area of the coarse aggregates and then model the mastic part by filling the irregular hollow shape with uniformly arranged balls. By deleting the mastic balls randomly, the voids were reconstructed consistent with the actual ratio. In the end, the virtual uniaxial compressive tests of AC-16 were simulated within PFC2D and the dynamic modulus at different load frequencies was predicted. The results indicated that the proposed algorithm could not only model the asphalt mixture precisely but also characterized its mechanical behavior as well.
Based on the Langley method and the EuroSkyRad (ESR) pack retrieval scheme, we carried out the retrieval of the aerosol properties for the CE–318 sunphotometer observation data from March 2012 to February 2014 in Kunming, China, and we explored the possible mechanisms of the seasonal variations. The seasonal variation of the aerosol optical depth (AOD) was unimodal and reached a maximum in summer. The retrieval analysis of the Angstrom exponent (α) showed the aerosol types were continental,doi:10.3390/rs11242911 fatcat:bxlupbodmjgs7beasp63dfopla
more »... ass burning (BB), and urban/industrial (UI); the content of the desert dust (DD) was low, and it may have contained a sea–salt (SS) aerosol due to the influence of the summer monsoon. All the aerosol particle spectra in different seasons showed a bimodal structure. The maximum and submaximal values were located near 0.2 μm and 4 μm, respectively, and the concentration of the aerosol volume was the highest in summer. In summer, aerosol particles have a strong scattering power but a weak absorption power; this pattern is the opposite in winter. The synergistic effect of the East Asian monsoon and the South Asian monsoon seasonal oscillations can have an important impact on the variation of the aerosol properties. The oscillation variation characteristic of the total vertical columnar water vapor (CWV) and the monsoon index was completely consistent. The aerosol types and sources in the Yunnan–Kweichow Plateau and the optical radiation properties were closely related to the monsoon circulation activities during different seasons and were different from other regions in China.
Louis, MO, USA), anti-Tubulin(ab18207, Abcam, Cambridge, MA), DAPI( H-1500, Vector Laboratories, Burlingame, CA, USA). ... The primary antibody was detected with Alexa Fluor 488-conjugated secondary antibody (R37114, Life Technologies, Waltham, MA, USA). ...doi:10.15698/cst2019.08.195 pmid:31440741 pmcid:PMC6702449 fatcat:jxdkruxd7bbvlonwojrd4uxkaq
-HUVECs or HMECs were starved in EBM for 16 h before trypsinization with Trypsin-EDTA (0.25%, 25200072, ThermoFisher Scientific, Waltham, MA) and incubated for 30 min with CM. ... Primary antibodies used in this study were: mouse-anti-Fibronectin (1:200, #610077, BD Biosciences, San Jose, CA), and rabbit-anti-α-SMA (1:200, ab5694, Abcam, Cambridge, MA). ...doi:10.1021/acs.bioconjchem.9b00262 pmid:31067032 pmcid:PMC6939887 fatcat:jch7lijdpnah3byoucngguq7ei
Cell lysates were separated on 10% SDS-polyacrylamide gels by electrophoresis and transferred to PVDF membrane (Millipore Immobilin P, Bedford, MA). ... For invasion assay, cells (5 × 10 4 ) were seeded in the upper chamber of transwell fitted with Matrigel-coated membrane (8 µm pore size, BD Biosciences, Bedford, MA). ...pmid:31218104 pmcid:PMC6556613 fatcat:a42kashorzatnmlxpcp63m473e
Vectors encoding short hairpin RNA (shRNA) were constructed by cloning RNA oligonucleotides (Invitrogen, Carlsbad, CA) into pLKO.1 vector (AddGene, Cambridge, MA). ... The invasive capability of cells was determined by using 24-well matrigel-coated transwell chambers with 8-μm pore size (BD Biosciences, Bedford, MA) as described  . 5×10 4 cells were added to the ...doi:10.18632/oncotarget.16730 pmid:28388589 pmcid:PMC5522093 fatcat:myafxy3dcndr3br2lodttgdazy
Viotti, Roberto Vivas, Anna Vogt, Nikolaus Voloshina, Irina von Braun, Kaspar Votruba, Viktor Waelkens, Christoffel Walker, Merle Walker, William Walker, Edward Wallerstein, George WANG, Xunhao ... van den Heuvel, Edward van Hamme, Walter Vaz, Luiz Paulo Vennes, Stephane Vierdayanti, Kiki Vilhu, Osmi Voloshina, Irina Wachter, Stefanie Wade, Richard Walder, Rolf Walker, William WANG, Xunhao ...doi:10.1017/s1743921315005694 fatcat:2fuohtecxzewzjpqydcwo24z7e
Louis, MO. [ 3 H] Thymidine was from Perkin-Elmer, (Waltham, MA). Media and PBS was purchased from Mediatech (Manassas, VA). ...doi:10.18632/oncotarget.2203 pmid:25071019 pmcid:PMC4171643 fatcat:uwfyqvbmanfuhetzzxnvyjgn6i
Voloshina, Irina von Braun, Kaspar Votruba, Viktor Wachter, Stefanie Wade, Richard Waelkens, Christoffel Walder, Rolf Walker, Merle Walker, William Walker, Edward Wallerstein, George WANG, Xunhao ... Lovas, Miklos Lugaro, Maria Lukyanyk, Igor Lutz, Barry Luu, Jane Luz, David Lyon, Ian MA, Yuehua Magee-Sauer, Karen Magnusson, Per MAIHARA, Toshinori Makalkin, Andrei Manara, Alessandro Mann ...doi:10.1017/s1743921315005682 fatcat:iiva4frvlvdjhe4k6jyk232vfm
Walker, Merle Fu, Jianning Melikian, Norair Walker, William Fu, Hsieh-Hai Mennickent, Ronald Walker, Edward Fujiwara, Tomoko Messina, Sergio Wallerstein, George Gahm, Goesta Michel, Eric Wang, Xunhao ... Fernandes, Francisco Mohan, Anita Voitenko, Yuriy Ferreira, João Moreno Insertis, Fernando Wang, Huaning Ferriz Mas, Antonio Morita, Satoshi Wang, Yi-ming Fisher, George Moriyama, Fumio Wang, ...doi:10.1017/s1743921310005430 fatcat:4f4baqdrirfp5jo76msovs7afa
The following antibodies were used for Western blotting and immunofluorescence: anti-FLAG (Millipore, Billerica, MA); anti-GST (Novagen); anti-E-cadherin, anti-Sec8, and anti-vinculin (BD Biosciences, ... line and cloned into pET42a (Novagen, Gibbstown, NJ). shRNA-expressing vectors were constructed by cloning shRNA oligonucleotides (Invitrogen, Carlsbad, CA) into the pLKO.1 vector (AddGene, Cambridge, MA ...doi:10.1091/mbc.e11-05-0449 pmid:22049025 pmcid:PMC3248907 fatcat:eprsxq3grzb2bl5gluft62gvz4
Ma Jiantang *JK 1989/No.6, pp.56-62 121. On the seasonal fluctuation of China (Chin.). Ma Jiantang *JY 1989/No.ll, pp.24-30 122. ... Liu Xunhao *NJW 1989/NO.12, pp.25-28 175. China's current agricultural Situa tion and policy. Tian Jiyun *BR 1990/No.2, pp.15-19 176. ...doi:10.11588/chakt.1990.januar.9135 fatcat:yt3tru237vbh5as4gl2yugktdu
hypothesis is further supported by two recent reports that demonstrated that the inability of ER Ca 2+ to enter the mitochondria upon cisplatin treatment might cause chemoresistance in cancer cells [Liwei Ma ...doi:10.1038/ncomms14634 pmid:28530221 pmcid:PMC5477507 fatcat:tmykbbe3wvcpzjbbihazunhpde
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