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201.
A composite was synthesized by irradiation of poly(butylene succinate) (PBS) and glass fiber (GF) in the presence of a polyfunctional monomer, trimethallyl isocyanurate (TMAIC), which accelerates gel formation of the matrix (PBS) in the composite. The highest gel fraction was achieved at 1% concentration of TMAIC at the dose level of 200 kGy compared to other concentrations. Mechanical properties of the composites were highly dependent on the gel fraction of the polymer and volume fraction of glass fiber reinforcement in the composite. Optimal conditions to synthesize a PBS/GF composite reaching maximum value of bending strength were 1% TMAIC, 67% fiber volume fraction, and irradiation dose of 200 kGy. These synthesized PBS/GF composites can be degraded by enzymes produced from the microorganism population in soil. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2122–2127, 2004 相似文献
202.
Behavior of noncircular tunnels excavated in stratified rock masses – Case of underground coal mines
Ngoc Anh Do Daniel Dias Van Diep Dinh Tien Tung Tran Van Canh Dao Viet Doan Dao Phuc Nhan Nguyen 《岩石力学与岩土工程学报(英文版)》2019,11(1):99-110
The amount of tunnels excavated along stratified/sedimentary rock masses in Quangninh coal mine area,Vietnam, is gradually increasing. Rock mass in Quangninh is characterized by beddings between rock layers. The behavior of stratified rock masses surrounding the tunnels depends on both the intact rock and the beddings between rock layers. The main characteristics of stratified rock masses that need to be considered are their heterogeneity and anisotropy. Depending on the dip angle of rock layers, movements and failure zones developed surrounding the tunnels can be asymmetrical over the vertical axis of tunnel. This asymmetry causes adverse behaviors of the tunnel structures. The objective of this study is to highlight convergences and yielded zones developed in rock masses surrounding noncircular tunnels in Quangninh coal mine area using a finite element method. The presence of bedding joints is explicitly simulated. The numerical results indicated that with the increase in dip angle of bedding joints, the stress asymmetry over the tunnel vertical axis increases. It gradually leads to an asymmetry of the failure zone surrounding the tunnel. An increase of rock mass quality means a decrease of rock mass sensitivity to the discontinuities. In addition,a dip angle of the bedding joints of approximately 45° could be considered as the critical angle at which the rock mass mechanism changes between sliding and bending. 相似文献
203.
Quang-Vu Bach Cuong Manh Vu Huong Thi Vu Hoa Binh Vu Tuyen Van Nguyen Soon Wong Chang Dinh Duc Nguyen Tuyet Anh Dang Thi Vu Ngoc Doan 《应用聚合物科学杂志》2020,137(2):48276
Carboxyl-terminated poly(acrylonitrile-co-butadiene) (CTBN)-grafted epoxidized linseed oil (ELO) (CTBN-g-ELO) was synthesized and used as an effective toughener to simultaneously enhance the mechanical properties and fracture toughness of epoxy resin (EP). The ELO was fabricated from linseed oil via epoxidation processing. The characteristics of the ELO and CTBN-g-ELO, such as the average molecular weight and chemical structure, were determined using gel permeation chromatography, proton nuclear magnetic resonance, and Fourier transform infrared spectroscopy. The effects of the CTBN-g-ELO loading on the characteristics of the EP were investigated in detail. The test results indicated that by adding 15 phr CTBN-g-ELO, the tensile strength, impact strength, and critical stress intensity factor (KIC) were significantly increased, by approximately 23.62, 91.8, and 33.8%, respectively, compared with pristine EP. The glass-transition temperature (Tg) and storage modulus, which were examined via dynamic mechanical thermal analysis and differential scanning calorimetry, respectively, exhibited decreasing trends. Scanning electron microscopy revealed that the CTBN-g-ELO existed as spherical particles in the EP, helping to stop the crack growth and change the crack growth directions. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48276. 相似文献
204.
Yichu Zheng Axel Fischer Michael Sawatzki Duy Hai Doan Matthias Liero Annegret Glitzky Sebastian Reineke Stefan C. B. Mannsfeld 《Advanced functional materials》2020,30(4)
In recent decades, organic memory devices have been researched intensely and they can, among other application scenarios, play an important role in the vision of an internet of things. Most studies concentrate on storing charges in electronic traps or nanoparticles while memory types where the information is stored in the local charge up of an integrated capacitance and presented by capacitance received far less attention. Here, a new type of programmable organic capacitive memory called p‐i‐n‐metal‐oxide‐semiconductor (pinMOS) memory is demonstrated with the possibility to store multiple states. Another attractive property is that this simple, diode‐based pinMOS memory can be written as well as read electrically and optically. The pinMOS memory device shows excellent repeatability, an endurance of more than 104 write‐read‐erase‐read cycles, and currently already over 24 h retention time. The working mechanism of the pinMOS memory under dynamic and steady‐state operations is investigated to identify further optimization steps. The results reveal that the pinMOS memory principle is promising as a reliable capacitive memory device for future applications in electronic and photonic circuits like in neuromorphic computing or visual memory systems. 相似文献
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207.
Wireless Networks - Wormhole attack is a serious security issue in Mobile Ad hoc Network where malicious nodes may distort the network topology and obtain valuable information. Many solutions,... 相似文献
208.
Khue Nhu Doan Dat Quoc Lai Phung T. Kim Le Tam Nhat Le 《International Journal of Food Science & Technology》2021,56(4):1987-1995
The use of ohmic heating (OH) to inactivate damaging elements in pomelo juice was evaluated. The work investigated the effect of frequencies (50–20 000 Hz) on pectin methylesterase (PME) and Lactobacillus plantarum (L. plantarum) in pomelo juice at 30 V cm−1 of electric field strength. The results show that frequency does not affect PME inactivation (P > 0.05) but affects bacterial reduction and has the most efficiency at 60 Hz, followed by 50 Hz, and in the frequency range at or higher than 500 Hz (P < 0.05). Additionally, the inactivation kinetics of PME and L. plantarum and the impact of nonthermal factors were given. The nonthermal element has contributed to the inactivation enhancement of L. plantarum and PME to reduce the necessary treatment temperature and time. The major spoilage bacteria and enzyme destruction in pomelo juice occurred faster under OH than under conventional heating (CH) suggesting that OH can be effectively used to pasteurise pomelo juice. 相似文献
209.
Van-Quoc-Truong Hoang T-Que-Phuong Phan Velusamy Senthilkumar Van-Thuan Doan Yong Soo Kim Minh-Vien Le 《International Journal of Applied Ceramic Technology》2019,16(4):1651-1658
In this report, undoped, mono and co-doped perovskite strontium titanate (SrTi1−(x+y)MoxVyO3) were synthesized by the sol-gel method, and their physical and optical properties were investigated. Furthermore, the photocatalytic degradation activities of the synthesized powders were conducted in 10 ppm methylene blue solution under visible-light irradiation. A maximum degradation efficiency of 91.5% was achieved in SrTi0.9Mo0.05V0.05O3 powder whereas only 59.9% of degradation was found in undoped SrTiO3. The improved efficiency in co-doped SrTiO3 was due to the doping of metal cations, Mo+6 and V+5 in the host lattice, which created impurity defect states thereby effectively reducing the bandgap energy of the semiconductor. 相似文献
210.
Pham Quoc Bao Abba S. I. Usman Abdullahi Garba Linh Nguyen Thi Thuy Gupta Vivek Malik Anurag Costache Romulus Vo Ngoc Duong Tri Doan Quang 《Water Resources Management》2019,33(15):5067-5087
Water Resources Management - One of the most challenging tasks in rainfall prediction is designing a reliable computational methodology owing the random and stochastic characteristics of... 相似文献