Applied Mechanics and Materials Vols. 556-562

Abstract: Graphene nanoplatelets (GNP) and nylon (PA) have been often used as thermal filler and matrix and respectively to produce composites. In this work, PA6/PA66/GNP thermal composites were prepared via a melt blending method. Mechanical properties, morphology, and thermal properties of PA6/PA66/GNP composites were investigated. Because the GNP is very expensive, we investigated to use Al₂O₃ and graphite and examined the characteristics of the prepared composites. Thermal conductivity values of PA6/PA66/GNP composites remarkably increased with increase of GNP contents mainly via layered dispersion in nylon matrix. The thermal conductivity of composite containing 50 wt % of GNP was measured as 5.03 W·m^–1·K^–1 at 30 °C, indicating an increase of more than 15 times compared with that of the neat PA6. When the Al₂O₃ was replaced for GNP, the thermal conductivity of composites decreased, but the mechanical properties improved. When graphite was used to replace for GNP, thermal conductivity basically remained unchanged but mechanical properties decreased.

Abstract: Wear-resistant polyurethane (PU)-based materials were prepared through addition of chemically modified aramid and PE fibers. The morphologies of PU-based materials were examined. We observed that treated fibers can be added to 10%, resulting in useful materials with very stable properties. Besides, bending strength of the materials increased from the 10 ~ 15 to 55 MPa, which greatly broadens the range of its applications. In this research, we also examined volume wear, heat resistance, and surface grinding marks morphology and observed very good performances.

Abstract: For variable selection in proteomic profile classification, we present a new local modeling procedure called interval support vector machine (iSVM). This procedure builds a series of SVM models in a window that moves over the whole spectral region and then locates useful spectral intervals in terms of the least complexity of SVM models reaching a desired error level. We applied iSVM in variable selection for proteomic profile classification. The results show that the proposed procedure are very promising for classification target-based variable selection and obtain much better classification than full-spectrum SVM model.

Abstract: We propose a new technique for cancer diagnosis from proteomic profile, which mainly contains four steps. Firstly, the original profiles are preprocessed by baseline correction, denoising, compression and rescaling. Then, the profiles are modelled by maximum margin criterion (MMC) analysis. After that, a consensus technique is utilized to identify the discriminant features. Finally, support vector machine (SVM) is applied to classify the modelling data. To study the validity of the proposed method, it is worked on classifying two proteomic profile datasets, the normal and the cancer samples. The results show that the method is efficient.

Abstract: Sintering reactions and fine structure of a biocomposite fabricated from hydroxyapatite (HA) powder, glass-ceramic (GC) powder and titanium mesh by dip coating method were investigated. A dense GC coating was initially deposited onto 3D Ti-mesh, which is to seal off the Ti-mesh. Then, a microporous HA-GC coating was deposited on the top of the dense GC coating to promote bone regeneration. Interfacial reactions play the key role for the coatings/substrate adhesion. During the fabrication process, the Ti substrate reacted with O₂ and produced the TiO₂ (rutile phase). Ti_xSi_y was detected in the GC coating/Ti substrate interfacial region. The average bonding strength between dense GC coating and Ti substrate was 27.1 MPa.

Abstract: In this study, CdLa₂S₄ hierarchical microspheres have been successfully synthesized through a hydrothermal method without any surfactants or templates. The crystal structure, morphology, and optical properties of the products were characterized by X-ray diffraction, scanning electron microscopy, and UV-vis diffuse reflectance spectroscopy. The results showed that the reaction time affects the structure and morphology of the CdLa₂S₄ products. Finally, the CdLa₂S₄ microspheres showed perfect photocatalytic properties for the degradation of the methyl orange solutions.

Abstract: The main components of Konjac glucomannan are glucose and glucomannan that are byڂ1-4 bond [ molar ratio is 1.6: (1~4) ] of high molecular weight non-ionic glucomannan, special glucose and mannose's ڂ-1-4chain structure isn't affected by the human digestive enzymes, and does not generate heat. According to the peculiar properties of konjac glucomannan, through the scientific experiment in the body of a rabbit to verify its unique immunological function, and then the human experiments after the effective experimental data statistics scientific analysis, finally the system can obtain the effect of konjac glucomannan on human immune system.

Abstract: Polyamides (PI)-matrix composite films with inorganic nanoTiO₂ have been fabricated by employing in situ polymerization. Before addition, TiO₂ particles were firstly modified with coupling agents (KH550). The electric breakdown strength and micromorphology of hybrid films were characterized and investigated. Results indicated that nanoTiO₂ particles were homogeneously dispersed in the PI matrix for the addition of coupling agents and the electric breakdown strength of PI/TiO₂ composite films with KH550 were better than unmodified PI composite film. The breakdown field strength and tensile modulus of PI composite film with the inorganic content of 5 wt% were 200.1 (KV/mm). So the using coupling agent can effectively improve the compatibility and the homogenous dispersion of nanoTiO₂ particles in PI matrix. Meanwhile, the procedure described here offers an effective and simple method to produce PI/TiO₂ with excellent electrical needed for future application in electrical engineering field.

Abstract: The impacts of operation parameters on agglomeration characteristics during biomass gasification in fluidized bed were studied experimentally in a 0.02MWt CFB gasifier using cotton stalk pellet as fuel. The experimental results indicated that among the temperature range (600 °C-800 °C), bed agglomeration would occur after a period running with sand, high alumina bauxite or periclase as the bed material, and potassium gathered on the surface of bed materials. In the process of the fluidized-bed gasification of biomass, air velocity affected the degree of bed agglomeration, and the agglomeration problem in return valve was more serious than that in main bed.

Abstract: Chemisorption of CO molecule on the (001) surface of δ-Pu using the generalized gradient approximation of the density functional theory with the Perdew-Burke-Ernzerhof exchange-correlation functional has been investigated without spin-orbit coupling at the non-spin-polarized level to better understand the interaction and chemical reaction of CO with Pu surface. Band structure and density of states before and after CO molecule chemisorption on the bridge position of the (001) surface have been compared and analyzed. The result shows that s and p states of CO molecule hybrid with Pu 6d states. Chemisorption energy for this adsorption site and repulsion energy between CO molecules are 0.615046eV and 0.96768eV, respectively.Key words: density functional;chemisorption;energy band;density of states;repulsion energy