Applied Mechanics and Materials Vols. 148-149

Abstract: The effects of Carbon fiber content and wear condition on the tribological properties of the composites were measured using a block on ring wear tester. The worn surface was investigated with a scanning electronic microscope and the wear mechanism was proposed. It was found that Carbon fiber improved the wear resistance of monomer casting polyamide 6 with the optimal content of Carbon being approximately 5 vol.%. The wear of PA6/Carbon fiber composite was lower than that of the PA6 and increased slowly while its friction coefficient decreased gradually with load. However, the friction coefficient of the composite was somewhat larger than that of monomer casting polyamide 6.

Abstract: In this paper, we present an automatic system for bloody image detection on the internet. A quick blood model in HIS color space is employed to identify the blood regions and then the fractal dimension and the information entropy of these regions are extracted. At last all the features are fed to a SVM -classifier to tell whether the image is bloody or not. Our experiments on real-world web image data indicate that this system can detect the bloody images with high recall ratio and high precision ratio.

Abstract: Ash deposition on the heat transfer tubes in the heat recovery steam generator (HRSG) can pose a significant influence on the operating efficiency and operational safety. In this paper a numerical deposition model was developed to predict particle deposition/rebounding in the thermal boundary layer as well as the influence of physical properties of deposits on the heat transfer process. In addition, deposition rate, deposits distribution and variations of deposits with the running time were also predicted by numerical simulation method. Compared with the other 4 sub areas, a strong deposition tendency along the running time occurred in the HR3. The predictive results from the ash deposition model showed that the HRSG had a significant increase in average furnace temperature and outlet temperature, and a decline in overall heat transfer efficiency as the deposits initiated, grew and maturated. In general, the predicted results is in good agreement with the field measurements.

Abstract: Semantic-SOA is becoming a key enabler for multi-disciplinary collaborative simulation and environment for supporting automatic integrated development. For meeting the challenges of Semantic-SOA applications in continuous/discrete systems and dynamic interoperation, we proposed a framework for developing flexible collaboration. In this paper, we present a DDL (Dynamic Description Logic) based framework to improving the existing Semantic-SOA. The extension of OWL-S with DDL allows us to implement clear representation of dynamic information and simulation activities. Furthermore, some new definitions of DDL are proposed to fit our simulation systems. In the end, a demo system is implemented.

Abstract: To meet the demand of food, pharmaceutical and cosmetics industry, study on the oligosaccharide- collagen peptide complexes has both scientific significance and application values. In the text, the preparation process and antioxidant capacity of oligochitosan-collagen peptides complexes were reported. The resultes indicated that the maximum DPPH radical-scavenging activity of oligochitosan-collagen peptide complexe was reached to 19.26 % when the ratio of oligochitosan to collagen peptide was 80:20, and the activity was stronger than the oligochitosan and collagen peptide at the same concentration in the detection range. In combination with the results of ion-exchange chromatography, we could concluded that the intermolecular chain associations were formed between oligochitosan chains and collagen peptide molecules driven by the electrostatic, intermolecular hydrogen bond and hydrophobic interactions. The results opened a new perspective on the utilization of oligochitosan-collagen peptide complexes as drug, food or cosmetic additives.

Abstract: Nanofluid is a kind of new engineering material consisting of nanometer-sized particles dispersed in base fluid. In this study, the thermal conductivity of four kinds of nanofluids is measured by the transient hot-wire method. The thermal conductivity of nanofluids is not only influenced by volume fraction of nanoparticles, but also by other factors such as diameter and suspension stability of nanoparticles and the temperature. The experimental results show that nanofluids have substantially higher thermal conductivity than the same liquids without nanoparticles.

Abstract: Based on finite element software MSC.Marc, the specific simulation model of cylindrical roller bearing was established, the axial equivalent stress distribution corresponding to Lundberg theoretical logarithmic crowned type was analyzed. Through the results of contact-mechanics properties and by means of design innovation, it is put forward that the Lundberg theoretical logarithmic crowned type can be replaced approximately by the multiple-variable-curvature arcs to avoid the stress concentration on the ends of roller. The influence of arc number on the axial equivalent and contact stress distribution was analyzed using finite element simulation. According to the numerical research, the appropriate number of curvature-changing arc segments was proposed. This method can be applicable to other types of line contact and the crown design of the roller

Abstract: An algorithm of independent component analysis from blind source separation domain is used and a Δλ-model strong-noise immunity is proposed in this work. The test results showed that maximal extraction error is respectively 0.28% and 3.7% under a SNR of 1/886 and an excellent agreementbetween the numerical simulation and the actual detection value is found, and the detection limit of test sample is improved from 16 ppb with the model based on common linear equations to 2 ppb using the proposed model.

Abstract: The single-phase Y-α-sialon ceramics with highly optical transmittance were produced by hot pressing starting mixtures of Si₃N₄, AlN, Al₂O₃ and Y₂O₃ at 1900 °C for 0.5 h in a nitrogen atmosphere. The resultant sialon shows very high optical transparency in the near infrared wavelength region, about 70% for 0.8 mm thickness. In addition to highly transmittance, the Y-α-sialon also show high hardness (19 GPa) and well fracture toughness (4 MPa•m^1/2), which attribute to the compound microstructure of uniform, equiaxed grain with a grain size of 2 μm and small aspect ration elongated α-sialon (<2) with a length no more than 5 μm. The high transparent was attribute to the uniform dense microstructure and pure single-phase α-sialon.

Abstract: It is demonstrated that the fine spheroidal and equiaxed non-dendritic microstructures required for semisolid casting can be formed by low superheat pouring and weak traveling-wave electromagnetic stirring (LSPWES). The effects of pouring temperature and then soaking treatment on the microstructure of A356 slurry were investigated. The results show that if A356 alloy is poured at 630 or 650°C and meanwhile stirred by an electromagnetic field at low power for a short time, the pouring process can be easily controlled and most solidified primary α-Al grains become spherical and only a few of them are rosette-like. Weak traveling-wave electromagnetic stirring makes the temperature field more homogeneous and makes the primary α-Al grains disperse in a large region, which leads to the spherical microstructure of primary α-Al grains. When the A356 alloy is soaked or reheated at the semisolid state, the primary α-Al grains ripen further and they become more spherical, which is favorable to the semisolid forming of A356 alloy.