Advanced Materials Research Vols. 415-417

Abstract: Nonresonant enhancements of third-order susceptibility χ(3)(-ω; ω, ω, -ω) have been investigated for zigzag carbon nanotube (n,0) bundles (n = 5, 7, 11, 13, 8, 10, 14, 16) based on the energy band theory combined with the classic anharmonic oscillator model. The obtained results show that the (3) values increase as circumference of tube varies in the order of 5<7<11<13 and 8<10<14<16 for (n,0) tube bundles, respectively. The origination of the large third-order susceptibility is ascribed to the circumference effect of individual tube. The nonresonant third-order susceptibility is estimated to be about 10-6 esu in the axial direction of (16,0) tube bundles, and it is possible for a good candidate to make optical phase conjugate device.

Abstract: The cellulose which is the extraction from Ochroma lagopus wood was dissolved in alkali system. With the BIS as crosslinker, wood cellulosic aerogels was prepared with high porosity and absorption rate. At last, the structure and properties were characterized using SEM, FT-IR, and absorption features. Cellulosic aerogels possessed a high bleaching ability to the discolor. The corresponding parameters were with 10 hours, 25 °C, and initial concentration of methylene blue 2.4×10^-4g/L, respectively. The quality of adsorption material 16 mg.

Abstract: In order to investigate the effect of interfacial adhesion on phase morphology, crystallization behavior and tensile property of magnesium hydroxide filled polypropylene (PP/MH) composites, PP blends with compatibilizers, compatibilised and uncompatibilised PP/MH composites were prepared in this work. Three different types of compatibilizers namely, polypropylene grafted-maleic anhydride (PP-g-MA), ethylene-octene copolymer grafted with maleic anhydride (POE-g-MA) and ethylene-vinyl acetate copolymer grafted with maleic anhydride (EVA-g-MA) were used to control the interfacial adhesion among the components. SEM analysis revealed the formation of an encapsulation structure in PP/compatibilizer/MH composites. The interfacial tension (γ_AB) and wetting coefficient (ω_α) results also confirmed the formation of encapsulation structure in these ternary composites. Addition of compatibilizers improved the interfacial adhesion between PP matrix and MH particles and resulted in improvement in tensile strength.

Abstract: Tricalcium silicate (Ca₃SiO₅) bioceramics have good bioactivity and compatibility. In simulated oral fluid they can induce teeth mineralization to repair the acid etched dental enamel. But teeth mineralization effect was relied on particles adhesive ability onto the enamel surface, so a new and simple method was established to evaluate the adherence quantitatively by optical micrograph analyzer and particle counter based on light blocking theory, and further verified Ca₃SiO₅ particle size affected mineralization effect in stimulated oral fluid (SOF) by nanoindentaion depth. The results indicated that particle size affected the adhesive capability and mineralization ability, in the size of 1-10μm is optimal selection as a toothpaste agent against early caries.

Abstract: By using a new kind of single-beam normalized photo-acoustic tomography spectroscopy (PAS-CT) technology with non-damage and weak signals detection, the photo-acoustic tomography spectroscopy, optical absorption properties and photosynthetic pigment content of the green and yellow leaves of Ficus altissima were studied. The results showed that: photo-acoustic tomography spectroscopy could be obtained from different chopping frequency. The more photosynthetic pigment content the leaves of Ficus altissima contain, the bigger optical absorption coefficient and the higher photosynthetic efficiency they have. In the research, we could find that the photosynthetic pigment content of the yellow leaves of Ficus altissma is lower than that of the green ones. As a result, the optical absorption coefficient and the photosynthetic efficiency of the yellow ones were smaller and lower than the green ones. The photo-acoustic tomography spectroscopy technology can be a kind of non-damage detection to confirm the growth of trees. It could make benefits to the controlled environmental forestry and increase forest production to meet the need of forest for 6 billion people. The research showed high practical value to the study and application of the photosynthesis of plants.

Abstract: Molecular imprinting polymer microspheres were prepared by precipitation polymerization with methacrylic acid as functional monomer and 1-phenyl-1-propanol as template. The effects of synthesis conditions, including the kind of solvent, polymerization temperature, the concentration of template and initiator, rotational speed and pre-polymerization time, on the characteristics of the molecularly imprinted polymer microspheres were studied. The rebinding experiments showed that the molecularly imprinted polymer microspheres synthesized by precipitation polymerization at 60°C, with acetonitrile as solvent and the concentrations of both template and initiator of 0.01mol L^-1, have good specific recognition and higher affinity capacity.

Abstract: PS was chemically modified by grafting with maleic anhydride to obtain PS-g-MAH on a single-screw extrude. The blending of starch and PS-g-MAH was carried out to prepare the degradable composite materials by melt extrusion on the extruder. The fractured surfaces of the blends were observed and discussed with the different incorporation of starch by a scanning electron microscope (SEM). The results exhibited that MAH improved the component compatibility of the blends. Then the starch/PS-g-MAH blends were used as the carrier for preparing bensulfuron-methyl CRFs. The bensulfuron-methyl CRFs’ release performance was investigated in the different pH value media by UV analysis. It was shown that the starch/PS-g-MAH matrix has obvious controlled-release function, and the release rate in a basic medium is much higher than in an acidic or neutral medium. The bensulfuron-methyl CRFs should have the longer validity in acidic soil, and have an important potential in reducing inefficient use and impact of pesticides in the environment.

Abstract: The objective of this study is to determine the best materials for the tibia/femoral combination of the prosthetic knee joint using commercial available FEM software. Insertion of these joints in human should not result in too much of discomfort and postoperative treatment. Further, the life and performance of the artificial joints is of prime concern. During activation, contact is established between tibia and femoral components leading to stresses at the interface, which in turn dictates the performance of these joints. The intensity of the developed stresses at the interface depends on several important factors such as the materials used for tibia/femoral components and the load acting on the bearing surfaces of the joint. To ensure reduction in the stress intensity, it is of utmost importance to select the best materials for tibia/femoral combination. In this regard, FEM the most powerful and widely accepted numerical tool to predict the state of stress is currently gaining importance in optimization of design of knee joint. In the light of the above, this paper discusses the modeling and finite element analysis of prosthetic tibia/femoral joint with different material combinations. The materials like stainless steel, titanium alloy and alumina ceramic are considered for the femoral component. Polyethylene and polyethylene chopped carbon fiber composite are considered for the tibial insert. The three dimensional model was developed using PRO E software for sagittal radius of 40 mm and 0 degree flexion angle, while load was varied from 500-2667N. An explicit finite element was generated using hyper mesh software and was solved by ANSYS. For a given load, a considerable reduction in the stress intensity at the interface of femur made of alumina ceramic and tibia made of polyethylene chopped carbon fiber composite have been observed when compared with other combinations of materials investigated.

Abstract: In order to accelerate the cultivation of micro-aerobic granular sludge for domestic sewage treatment, an expanded granular sludge bed (EGSB) reactor seeded with excess sludge was employed. It was found that micro-aerobic granules can form and grew compact within one month, and remained stable during the later operation, the mature cultivation had average particle size of 0.81mm, and 64% of the granules had settling velocity above 35m•h^-1. Moreover, excellent COD and nitrogen removal were obtained. For hydraulic retention time (HRT) of 5h, as the recirculation ratio and oxygenation rate were set at 6.5 and 0.25g•L^-1d^-1 respectively, COD removal ranged in 80%-91%, leaving effluent COD below 50mg•L^-1. The removal efficiency of ammonium and total nitrogen (TN) were 72%-89% and 76%-87%, respectively with effluent concentration down to 3-12mg•L^-1 and 5-14mg•L^-1. Results showed that the efficiency of simultaneous nitrogen removal was much influenced by effluent recirculation and oxygenation rate in micro-aerobic EGSB reactor.

Abstract: The design of internal space of the building is an important part of modern high-rise office building. Based on the long term practice of the design of modern high-rise building, the green design of modern high-rise office building internal space from the aspect of optimum design of core tube, functional space, healthy space, humanized space are discussed. According to a green design of modern high-rise office building internal space in Guangzhou, the design skills are analyzed and explained, which provides a reference for other projects.