On-line acoustic viscometry in oil condition monitoring

The paper describes the theoretical standpoints of developing magnetoelastic viscometers and a concept of viscosity measurement. The magnetoelastic viscometer has shown the readings close to the capillary viscometer. Testing of the oils with PMMA viscosity-index improvers by viscometers has indicated changes in rheological properties observed in the non-Newtonian behavior of the oils. With increase in content or molecular weight of the improver, the non-Newtonian behavior of the oil appeared at lower frequencies of viscosity measurements.     

Analysis on the Latest Assessment Criteria of ASME B31G-2009 for the Remaining Strength of Corroded Pipelines

ASME B31G provides the most basic and widespread method in assessing the remaining strength of corroded pipelines. The third edition B31G (ASME B31G-2009) is the latest revision issued by the American National Standards Institute (ANSI) and is used as the basis for this study. This article discusses the development process of ASME B31G, and presents the comparative analysis of ASME B31G, RSTRENG, and DNV RP-F101. The predicted failure pressures are calculated by each standard mentioned above, based on 35 groups of data for full-size pipe tests collected from the literature. The deviations between the predicted values and the actual experiment results are discussed. Finally, practical applications are compared among the assessment methods. The investigation showed that predictions based on ASME B31G-2009 are much more accurate than predictions based on the previous editions of B31G. The applications of ASME B31G-2009 and RSTRENG 0.85 dL effectively improve the pipe’s conveying efficiency and optimize the cost of managing the piping system. However, they both are applicable only for evaluating the medium- and low-strength pipe steels. In contrast, DNV RP-F101 is applicable to the medium- and high-strength pipe steels, but its results are often not safe for application to the lower-strength pipe steels.     

Large-scale synthesis of hierarchical alpha-FeOOH flowers by ultrasonic-assisted hydrothermal route

In this paper, we report a facile, an environmental friendly ultrasonic-assisted hydrothermal route for preparation of goethite flower structures using Fe nanopowders at low temperature (85°C). The flower structure consisted of tens of hundreds of nanowires and such structures can further self-assemble with the flake with micro size area. Structural, morphological, and elemental analysis revealed that the products consisted of flower-like structures with high structural uniformity, good crystal quality, and high yields. Influencing factors such as the reaction temperature, pH value, and the deposition time were systematically investigated. A possible formation mechanism was proposed on the basis of the experimental results. Magnetic measurements showed that the as-obtained goethite flowers exhibited weakly ferromagnetic characteristics at room temperature, which were quite different from those of the corresponding bulk materials.     

An approximation method of origin–destination flow traffic from link load counts

Traffic matrix (TM) is a key input of traffic engineering and network management. However, it is significantly difficult to attain TM directly, and so TM estimation is so far an interesting topic. Though many methods of TM estimation are proposed, TM is generally unavailable in the large-scale IP backbone networks and is difficult to be estimated accurately. This paper proposes a novel method of TM estimation in large-scale IP backbone networks, which is based on the generalized regression neural network (GRNN), called GRNN TM estimation (GRNNTME) method. Firstly, building on top of GRNN, we present a multi-input and multi-output model of large-scale TM estimation. Because of the powerful capability of learning and generalizing of GRNN, the output of our model can sufficiently capture the spatio-temporal correlations of TM. This ensures that the estimation of TM can accurately be attained. And then GRNNTME uses the procedure of data posttreating further to make the output of our model closer to real value. Finally, we use the real data from the Abilene Network to validate GRNNTME. Simulation results show that GRNNTME can perform well the accurate and fast estimation of TM, track its dynamics, and holds the stronger robustness and lower estimation errors.     

Optimisation of location and dimension of SMC precharge in compression moulding process

The main goal of the present study is to optimise the precharge conditions such as the precharge location and dimensions that give significant effects on the mechanical performance of composite structures manufactured by the compression moulding process. As preliminary step of optimisation, we developed a manufacturing simulation program to predict the fibre volume fraction and fibre orientation. And coupled with this simulation program and a structural analysis program, a genetic algorithm (GA) is implemented to optimise the precharge conditions. The penalty function method and the repair algorithm are modified for handling constraints. The repair algorithm is applied to a symmetric structure and an arbitrary shape structure to find optimal precharge conditions.     

Synthesis and photovoltaic property of poly(3-octylthiophene)/titanium dioxide/ferric oxide composite

Titanium dioxide and ferric oxide were prepared by the supercritical fluid drying (SCFD) method. A conducting polymer composite, poly(3-octylthiophene)/titanium dioxide/ferric oxide (POT/TiO₂/Fe₂O₃) was first synthesized by chemical method. Transmission electron microscope (TEM) and scanning electron microscope (SEM) depicted the morphology of the samples, defining that TiO₂ and Fe₂O₃ were successfully coated by poly(3-octylthiophene) molecules. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (IR) showed the chemical interaction between poly(3-octylthiophene) and inorganic compounds in the composite. Cyclic voltammetry (CV) curves showed that the forbidden band gap of the POT/TiO₂/Fe₂O₃ composite is 0.691 eV, realizing the complementary advantages of n and p semiconductor. UV–vis spectra (UV) and fluorescence spectra (PL) showed that its optical performance is far superior to poly(3-octyl thiophene), titanium dioxide and ferric oxide separately. Solar cell was sensitized by POT/TiO₂/Fe₂O₃. A solar-to-electric energy conversion efficiency of 0.499% was attained with the system.     

Preparation and electrochemical performances of graphite oxide/polypyrrole composites

Graphite oxide/polypyrrole composites (GPys) were prepared by in situ polymerization and reduced by NaBH₄ to prepare reduced graphite oxide/polypyrrole composites (R-GPys). On the basis of the morphological and structural characterization of the composites by Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD) and transmission electron microscopy (TEM) tests, the electrochemical performances of the composites were investigated by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance techniques. The experimental results showed that the specific capacitances of the composites before and after reduction (197 and 180 F/g) were highly improved compared with that of pristine graphite oxide (11 F/g) and polypyrrole (112 F/g), respectively. The capacitance retention of about 73% for R-GPys compared with 12% for PPy and 47% for GPys after 1200 cycles indicated the high cycle stability of the R-GPys and its potential as an electrode material for supercapacitor applications.     

Schiff碱-双（呋喃甲醛）缩联苯胺的合成与光谱研究

Schiff碱在材料、催化剂和分析化学方面等的研究都有了很大进展,也越来越受到重视。文章以呋喃甲醛和联苯胺为起始原料,在无水甲醇的溶剂中合成了一种新的Schiff碱,收率为85.0%。反应的最佳条件是呋喃甲醛与联苯胺的比例为3∶1,反应时间为1h,反应温度为30℃。这种新的Schiff碱结构且通过了IR和UV光谱测定。     

Tests on inclined,tapered and STS concrete-filled steel tubular (CFST) stub columns

This paper is an attempt to study the behaviour of the inclined, tapered and straight-tapered-straight (STS) concrete-filled steel tubular (CFST) stub columns. A total of 34 specimens were tested. The main parameters were the column type (inclined, tapered and STS), inclined or tapered angle (from 0°to 9°) and the cross-sectional type (circular and square). Comparisons with predicted cross-sectional strengths were made using the existing codes: AIJ-2008, AISC-2005, BS5400-2005, DBJ-13-51-2003 and EC4-2004.