Failure characteristics of combined coal-rock with different interfacial angles

Zhao, Tong-Bin,Guo, Wei-Yao,Lu, Cai-Ping,Zhao, Guang-Ming Techno-Press 2016 Geomechanics & engineering Vol.11 No.3

In order to investigate the influence of the interfacial angel on failure characteristics and mechanism of combined coal-rock mass, 35 uniaxial/biaxial compressive simulation tests with 5 different interfacial angels of combined coal-rock samples were conducted by PFC2D software. The following conclusions are drawn: (1) The compressive strength and cohesion decrease with the increase of interfacial angle, which is defined as the angle between structure plane and the exterior normal of maximum principal plane, while the changes of elastic modulus and internal friction angle are not obvious; (2) The impact energy index $K_E$ decreases with the increase of interfacial angle, and the slip failure of the interface can be predicted based on whether the number of acoustic emission (AE) hits has multiple peaks or not; (3) There are four typical failure patterns for combined coal-rock samples including I (V-shaped shear failure of coal), II (single-fracture shear failure of coal), III (shear failure of rock and coal), and IV (slip rupture of interface); and (4) A positive correlation between interfacial angle and interface effect is shown obviously, and the interfacial angle can be divided into weak-influencing scope ($0-15^{\circ}$), moderate-influencing scope ($15-45^{\circ}$), and strong-influencing scope (> $45^{\circ}$), respectively. However, the confining pressure has a certain constraint effect on the interface effect.

Three-dimensional vibration analysis of 3D graphene foam curved panels on elastic foundations

Li-Cai Zhao,Shi-Shuenn Chen,Mohammad Khajehzadeh,Mariwan Araz Yousif,Vahid Tahouneh 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.43 No.1

This paper has focused on presenting a three dimensional theory of elasticity for free vibration of 3D-graphene foam reinforced polymer matrix composites (GrF-PMC) cylindrical panels resting on two-parameter elastic foundations. The elastic foundation is considered as a Pasternak model with adding a Shear layer to the Winkler model. The porous graphene foams possessing 3D scaffold structures have been introduced into polymers for enhancing the overall stiffness of the composite structure. Also, 3D graphene foams can distribute uniformly or non-uniformly in the shell thickness direction. The effective Young’s modulus, mass density and Poisson’s ratio are predicted by the rule of mixture. Three complicated equations of motion for the panel under consideration are semi-analytically solved by using 2-D differential quadrature method. The fast rate of convergence and accuracy of the method are investigated through the different solved examples. Because of using twodimensional generalized differential quadrature method, the present approach makes possible vibration analysis of cylindrical panels with two opposite axial edges simply supported and arbitrary boundary at the curved edges. It is explicated that 3D-GrF skeleton type and weight fracti

In situ Gelatinization of Starch using Hot Stage Microscopy

Canhui Cai,Jinwen Cai,Lingxiao Zhao,Cunxu Wei 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.1

Starch gelatinization is important in food processingand industrial use. Granule swelling and gelatinizationtemperature of 11 starches from different plants wereinvestigated in situ using hot stage microscopy duringheating. The amylose content, swelling power, pastingtemperature and thermal property of these starches werealso measured. The results showed that hot stage microscopywas suitable for measuring granule swelling and thegelatinization temperature of starch during heating. Thesectional area swelling percentage of starch granulesmeasured using hot stage microscopy was significantlypositively correlated with the swelling power. The gelatinizationtemperature measured using hot stage microscopy wassignificantly positively correlated with the pasting temperatureand with the thermal property for all 11 starches. For ricestarches with the same crystallinity and similar size, thegelatinization temperature was negatively correlated withthe amylose content and positively correlated with theswelling power and the sectional area swelling percentageat 95ºC.

장구령여당대유가문론적불도특색(張九齡여唐代儒家文론的佛道特色)

조채화 ( Cai Hua Zhao ) 전북대학교 인문학연구소 2011 건지인문학 Vol.6 No.-

Zhang Jiuling thought that literature should reflect "the belongings" which include nature, society, all aspects of life. Zhang Jiuling`s "clarify the way" is the Confucian way when pointing to the socio-political con-notations; and which contains with Buddhism and Taoism when on self-cultivation, The connotation of "belongings" and "clarify the way" is a typical embodiment of the impact of integration of the three religions at the Xuanzong times, which is typical of the Tang dynasty Confucian characteristics of literary theory that explicit Confucian way and inherent is both Buddhism and Taoism.

Experimental investigation and stability analysis on dense-phase pneumatic conveying of coal and biomass at high pressure

Liang Cai,Cai Jiaying,Xu Guiling,Xu Pan,Chen Xiaoping,Zhao Changsui 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.2

Conveying characteristics and flow stability are very important for design and control of a conveying system at high pressure. The influences of operating parameters and material properties on conveying characteristics were investigated in an experimental test facility with a conveying pressure up to 4MPa. Wavelet transform and Shannon entropy analysis were applied to analyzing pressure drops through horizontal pipe in order to obtain the stability criterion. Results indicated that the mass flow rate of biomass decreased, while the mass flow rate of pulverized coal increased at first and then decreased with the increase in fluidization velocity. Solid loading ratios for four kinds of powders decreased with the increase in fluidization velocity. Conveying phase diagrams and pressure drops through different test sections of pulverized coal and biomass at high pressure were obtained and analyzed. The influences of coal category,fracture characteristics and particle size on conveying characteristics were determined.

Vibration analysis of damaged core laminated curved panels with functionally graded sheets and finite length

Li-Cai Zhao,Shi-Shuenn Chen,Yi-Peng Xu,Vahid Tahouneh 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.38 No.5

The main objective of this paper is to study vibration of sandwich open cylindrical panel with damaged core and FG face sheets based on three-dimensional theory of elasticity. The structures are made of a damaged isotropic core and two external face sheets. These skins are strengthened at the nanoscale level by randomly oriented Carbon nanotubes (CNTs) and are reinforced at the microscale stage by oriented straight fibers. These reinforcing phases are included in a polymer matrix and a three-phase approach based on the Eshelby-Mori-Tanaka scheme and on the Halpin-Tsai approach, which is developed to compute the overall mechanical properties of the composite material. Three complicated equations of motion for the panel under consideration are semi-analytically solved by using 2-D differential quadrature method. Several parametric analyses are carried out to investigate the mechanical behavior of these multi-layered structures depending on the damage features, through-the-thickness distribution and boundary conditions. It is seen that for the large amount of power-law index “P”, increasing this parameter does not have significant effect on the non-dimensional natural frequency parameters of the FG sandwich curved panel. Results indicate that by increasing the value of isotropic damage parameter “D” up to the unity (fully damaged core) the frequency would tend to become zero. One can dictate the fiber variation profile through the radial direction of the sandwich panel via the amount of “P”, “b” and “c” parameters. It should be noticed that with increase of volume fraction of fibers, the frequency parameter of the panels does not increase necessarily, so by considering suitable amounts of power-law index “P” and the parameters “b” and “c”, one can get dynamic characteristics similar or better than the isotropic limit case for laminated FG curved panels.

Bacterial Cellulose Immobilized S. cerevisiae as Microbial Sensor for Rapid BOD Detection

Chenyu Zhao,Guangshu Wang,Mengtao Sun,Zewei Cai,Zichu Yin,Yurong Cai 한국섬유공학회 2021 Fibers and polymers Vol.22 No.5

As one of the most important parameters to characterize the organic pollution of water, biochemical oxygendemand (BOD) determined through a rapid, in situ and on line method is very attractive. In this paper, a new BOD biosensorhas been developed, which are composed of the ecofriendly precursor of Saccharomyces cerevisiae (S. cerevisiae) embeddedin bacterial cellulose (BC) matrix and the Ketjen Black (KB) modified glassy-carbon electrode. Furthermore, a doublemediatorsystem is constructed using potassium ferricyanide and menadione in reaction cell to transfer electron from themicrobe to electrode. The responses of glucose glutamic acid (GGA) standard solutions are amperomertrically measured withan applied potential of 0.25 V versus Hg/Hg2Cl2 in a three-electrode system. Under the optimum conditions, the (BC/S. cerevisiae-menadione)/KB modified electrode shows a high operational stability with relative standard deviation (RSD) of4.16 % (fourteen assays), a good repeatability (RSD=3.10 %), a fast response time (in 20 minutes) and a wide linear range(from 10-220 mg O2 l-1). The BOD values measured by this method have been highly correlated with the standard BOD 5-daymethod for wastewater samples (R2=0.9859, n=3), indicating that it can meet the requirement of BOD rapid measurement.

Metastasis associated genomic aberrations in stage II rectal cancer

Hong Zhao,Zhi-Zhou Shi,Rui Jiang,Dong-Bing Zhao,Hai-Tao Zhou,Jian-Wei Liang,Xin-Yu Bi,Jian-Jun Zhao,Zhi-Yu Li,Jian-Guo Zhou,Zhen Huang,Ye-Fan Zhang,Jian Wang,Xin Xu,Yan Cai,Ming-Rong Wang,Yu Zhang 한국유전학회 2016 Genes & Genomics Vol.38 No.11

Genomic aberrations of rectal carcinoma, especially DNA copy number changes associated with metastasis were largely unclear. We aim to identify the metastasis associated biomarkers in stage II rectal cancer. Formalin-fixed, paraffin-embedded primary tumor tissues of stage II rectal carcinoma were analyzed by array-based comparative genomic hybridization, and genomic aberrations were identified by Genomic Workbench and SAM software. Copy number changes and mRNA expressions were validated by Real-time PCR in an independent rectal cancer samples. The results showed that the most frequent gains in stage II rectal cancer were at 1q21.2-q23.1, 3p21.31, 11q12.2-q23.3, 12q24.11-q24.31, 12q13.11-q14.1 and losses in 18q11.2-q23, 17q21.33-q22, 13q31.1-q31.3, 21q21.1-q21.3, 8p23.3-p23.1 and 4q22.1-q23. Twenty-two amplifications and five homozygous deletions were also identified. We further found that S100A1 (1q21.3-q23.1), MCM7 (7q22.1) and JUND (19p13.11) were amplified and overexpressed in stage II rectal cancer. Interestingly, the genomic aberrations affected 14 signaling pathways including VEGF signaling pathway and fatty acid metabolism. Most importantly, loss of 13q31.1-q34 and gain of 1q44 were associated with distant metastasis. Our results indicated that these metastasis associated genomic changes may be useful to reveal the pathogenesis of rectal cancer metastasis and identify candidate biomarkers.

Recombinant Human Granulocyte Colony-Stimulating Factor Promotes Preinvasive and Invasive Estrogen Receptor-Positive Tumor Development in MMTV-erbB2 Mice

Chun Ling Zhao,Guang Ping Zhang,Zheng Zheng Xiao,Zhi Kun Ma,Cai Peng Lei,Shi Yuan Song,Ying Ying Feng,Ya Chao Zhao,Xiao Shan Feng 한국유방암학회 2015 Journal of breast cancer Vol.18 No.2

Purpose: We investigated whether recombinant human granulocyte colony-stimulating factor (rhG-CSF) could promote the development of preinvasive and invasive breast cancer in mouse mammary tumor virus (MMTV-erbB2) mice with estrogen receptor- positive tumors. Methods: MMTV-erbB2 mice were randomly divided into three experimental groups with 20 mice in each group. MMTV-erbB2 mice were treated with daily subcutaneous injections of vehicle or rhG-CSF (low-rhG-CSF group, rhG-CSF 0.125 μg; vehicle-rhG-CSF group, normal saline 0.25 μg; and high-rhG-CSF group, rhG-CSF 0.25 μg) at 3 months of age. Cellular and molecular mechanisms of G-CSF action in mammary glands were investigated via immunohistochemistry and reverse transcription polymerase chain reaction. Results: Low, but not high, rhG-CSF doses significantly accelerated mammary tumorigenesis in MMTV-erbB2 mice. Short-term treatment with rhG-CSF could significantly promote the development of preinvasive mammary lesions. The cancer prevention effect was associated with reduced expression of proliferating cell nuclear antigen, cluster of differentiation 34, and signal transducers and activators of transcription 3 in mammary glands by >80%. Conclusion: We found that G-CSF was regulated by rhG-CSF both in vitro and in vivo. Identification of G-CSF genes helped us further understand the mechanism by which G-CSF promotes cancer. Low doses of rhG-CSF could significantly increase tumor latency and increase tumor multiplicity and burden. Moreover, rhG-CSF effectively promotes development of both malignant and premalignant mammary lesions in MMTV-erbB2 mice.

Photochemical synthesis of 2,3,9,10-tetrabromopentacene: its unusual photodimerization

Zhao, Yuewei,Cai, Xichen,Danilov, Eugene,Li, Guifeng,Neckers, Douglas C. Korean Society of Photoscience 2009 Photochemical & photobiological sciences Vol.8 No.1

The photogeneration of 2,3,9,10-tetrabromopentacene from its precursor dione by photodecarbonylation was investigated. An unusual photodimer, 3,3',9,9',10,10'-hexabromo-2,2'-bipentacene, is produced.