The bending problem of a functionally graded anisotropic cantilever beam subjected to thermal and uniformly distributed load is investigated, with material parameters being arbitrary functions of the thickness coordinate. The heat conduction problem is treated as a 1D problem through the thickness. Based on the elementary formulations for plane stress problem, the stress function is assumed to be in the form of polynomial of the longitudinal coordinate variable, from which the stresses can be derived. The stress function is then determined completely with the compatibility equation and boundary conditions. A practical example is presented to show the application of the method.

Based on the Canadian Standards Association (CSA) criteria, 105 pullout specimens were tested to investigate the effect of different rib geometries on bond strength of glass fiber reinforced polymer (GFRP) rebars embedded in concrete. Two kinds of conventional reinforcing rebars were also studied for comparison. Each rebar was embedded in a 150 mm concrete cube, with the embedded length being four times the rebar diameter. The experimental parameters were the rebar type, rebar component, rebar diameter, rebar surface texture, rib height, rib spacing and rib width. Theoretical analysis was also carried out to explain the experimental phenomena and results. The experimental and theoretical results indicated that the bond strength of GFRP rebars was about 13%~35% lower than that of steel rebars. The bond strength and bond-slip behavior of the specially machined rebars varied with the rebar type, rebar diameter, rebar surface texture, rib height, rib spacing and rib width. Using the results, design recommendations were made concerning optimum rib geometries of GFRP ribbed rebars with superior bond-slip characteristics, which concluded that the optimal rib spacing of ribbed rebars is the same as the rebar diameter, and that the optimal rib height is 6% of the rebar diameter.

The cable-strut structural system is statically and kinematically indeterminate. The initial pre-stress is a key factor for determining the shape and load carrying capacity. A new numerical algorithm is presented herein for the initial pre-stress finding procedure of complete cable-strut assembly. This method is based on the linear adjustment theory and does not take into account the material behavior. By using this method, the initial pre-stress of the multi self-stress modes can be found easily and the calculation process is simplified and efficient also. Finally, the initial pre-stress and structural performances of a particular Levy cable dome are analyzed comprehensively. The algorithm has proven to be efficient and correct, and the numerical results are valuable for practical design of Levy cable dome.

The characteristic properties of shell element with similar shapes are used to generate a so-called super element for the analysis of the crack problems for cylindrical pressure vessels. The formulation is processed by matrix condensation without the involvement of special treatment. This method can deal with various singularity problems and it also presents excellent results to crack problems for cylindrical shell. Especially, the knowledge of the kind of singular order is not necessary in super element generation; it is very economical in terms of computer memory and programming. This method also exhibits versatility to solve the problem of kinked crack at cylindrical shell.

An expansion theory of spherical cavities in strain-softening materials with different moduli of tension and compression was presented. For geomaterials, two controlling parameters were introduced to take into account the different moduli and strain-softening properties. By means of elastic theory with different moduli and stress-softening models, general solutions calculating Tresca and Mohr-Coulomb materials’ stress and displacement fields of expansion of spherical cavity were derived. The effects caused by different elastic moduli in tensile and compression and strain-softening rates on stress and displacement fields and development of plastic zone of expansion of cavity were analyzed. The results show that the ultimate expansion pressure, stress and displacement fields and development of plastic zone vary with the different elastic moduli and strain-softening properties. If classical elastic theory is adopted and strain-softening properties are neglected, rather large errors may be the result.

Based on new high-resolution seismic profiles and existing structural and sedimentary results, a superposition deformation model for Cenozoic Bachu Uplift of northwestern Tarim Basin, northwestern China is proposed. The model presents the idea that the Bachu Uplift suffered structure superposition deformation under the dual influences of the Cenozoic uplifting of Southern Tianshan and Western Kunlun orogen, northwestern China. In the end of the Eocene (early Himalayan movement), Bachu Uplift started to be formed with the uplifting of Western Kunlun, and extended NNW into the interior of Kalpin Uplift. In the end of the Miocene (middle Himalayan movement), Bachu Uplift suffered not only the NNW structure deformation caused by the Western Kunlun uplifting, but also the NE structure deformation caused by the Southern Tianshan uplifting, and the thrust front fault of Kalpin thrust system related to the Southern Tianshan orogen intrudes southeastward into the hinterland of Bachu Uplift and extends NNE from well Pi1 to Xiaohaizi reservoir and Gudongshan mountain, which resulted in the strata folded and denuded strongly. In the end of the Pliocene (late Himalayan movement), the impact of Southern Tianshan orogen decreased because of the stress released with the breakthrough upward of Kalpin fault extending NE, and Bachu Uplift suffered mainly the structure deformation extending NW-NNW caused by the uplifting of Western Kunlun orogen.

In this paper modelling of the translational motion of transportation rail-guided cart with rope suspended payload is considered. The linearly moving cart, driven by a travel mechanism, is modelled as a discrete six degrees of freedom (DOF) dynamic system. The hoisting mechanism for lowering and lifting the payload is considered and is included in the dynamic model as one DOF system. Differential equations of motion of the cart elements are derived using Lagrangian dynamics and are solved for a set of real-life constant parameters of the cart. A two-sided interaction was observed between the swinging payload and the travel mechanism. Results for kinematical and force parameters of the system are obtained. A verification of the proposed model was conducted.

An important functioning mechanism of biological macromolecules is the transition between different conformed states due to thermal fluctuation. In the present paper, a biological macromolecule is modeled as two strands with side chains facing each other, and its stochastic dynamics including the statistics of stationary motion and the statistics of conformational transition is studied by using the stochastic averaging method for quasi Hamiltonian systems. The theoretical results are confirmed with the results from Monte Carlo simulation.

In this paper, a new nonlinear autonomous system introduced by Chlouverakis and Sprott is studied further, to present very rich and complex nonlinear dynamical behaviors. Some basic dynamical properties are studied either analytically or numerically, such as Poincaré map, Lyapunov exponents and Lyapunov dimension. Based on this flow, a new almost-Hamilton chaotic system with very high Lyapunov dimensions is constructed and investigated. Two new nonlinear autonomous systems can be changed into one another by adding or omitting some constant coefficients.

Straight Darrieus wind turbine has attractive characteristics such as the ability to accept wind from random direction and easy installation and maintenance. But its aerodynamic performance is very complicated, especially for the existence of dynamic stall. How to get better aerodynamic performance arouses lots of interests in the design procedure of a straight Darrieus wind turbine. In this paper, mainly the effects of number of blades and tip speed ratio are discussed. Based on the numerical investigation, an assumed asymmetric straight Darrieus wind turbine is proposed to improve the averaged power coefficient. As to the numerical method, the flow around the turbine is simulated by solving the 2D unsteady Navier-Stokes equation combined with continuous equation. The time marching method on a body-fitted coordinate system based on MAC (Marker-and-Cell) method is used. O-type grid is generated for the whole calculation domain. The characteristics of tangential and normal force are discussed related with dynamic stall of the blade. Averaged power coefficient per period of rotating is calculated to evaluate the eligibility of the turbine.

The characteristics of the fluidic flowmeter, which is a combination of impinged concave wall and bistable fluid amplifier, is investigated by experimental studies and numerical simulations. The numerical approaches are utilized to examine the time dependent flow field and pressure field inside the proposed flowmeter. The effect of varying structural parameters on flow characteristics of the proposed fluidic flowmeter is investigated by computational simulations for the optimization. Both the simulation and experimental results disclose that the hydrodynamic vibration, with the same intensity, frequency and 180° phase shift, occurs at axisymmetric points in the feedback channel of the fluidic flowmeter. Using the structural combination of impinged concave wall and bistable fluid amplifier and differential signal processing technique, a novel fluidic flowmeter with excellent immunity and improved sensibility is developed.

The highly nonlinear behavior of the system limits the performance of classical linear proportional and integral (PI) controllers used for hot rolling. An active disturbance rejection controller is proposed in this paper to deal with the nonlinear problem of hydraulic servo system in order to preserve fast response and small overshoot of control system. The active disturbance rejection (ADR) controller is composed of nonlinear tracking differentiator (TD), extended state observer (ESO) and nonlinear feedback (NF) law. An example of the hydraulic edger system case study is investigated to show the effectiveness and robustness of the proposed nonlinear controller, especially, in the circumstance of foreign disturbance and working condition variation, compared with classic PI controller.

The linear stability of fiber suspensions between two concentric cylinders rotating independently is studied. The modified stability equation is obtained based on the fiber orientation model and Hinch-Leal closure approximation. The primary instabilities and bicritical curves have been calculated numerically. The critical Reynolds number, wavenumber and wave speeds of fiber suspensions as functions of the aspect ratio, volume concentration of the fibers and the gap width of cylinders are obtained.

In this paper, a geometric approach to fault detection and isolation (FDI) is applied to a Multiple-Input Multiple-Output (MIMO) model of a frame and the FDI results are compared to the ones obtained in the Single-Input Single-Output (SISO), Multiple-Input Single-Output (MISO), and Single-Input Multiple-Output (SIMO) cases. A proper distance function based on parameters obtained from parametric system identification method is used in the geometric approach. ARX (Auto Regressive with eXogenous input) and VARX (Vector ARX) models with 12 parameters are used in all of the above-mentioned models. The obtained results reveal that by increasing the number of inputs, the classification errors reduce, even in the case of applying only one of the inputs in the computations. Furthermore, increasing the number of measured outputs in the FDI scheme results in decreasing classification errors. Also, it is shown that by using probabilistic space in the distance function, fault diagnosis scheme has better performance in comparison with the deterministic one.

Performance of a pulse tube cooler significantly depends on the efficient operation of its regenerator. Influence of input acoustic power on regenerator’s performance is simulated and analyzed with simple harmonic analysis method. Given regenerator’s dimensions and pressure ratio, there is an optimal input acoustic power for achieving a highest coefficient of performance, due to a compromise between relative time-averaged total energy flux in regenerator and relative acoustic power at regenerator’s cold end. Additionally, optimal dimensions of regenerator are also estimated and presented for different input acoustic powers. The computed optimal diameter obviously increases with increase of input acoustic power, while the optimal length decreases slightly, and as a result, a larger input acoustic power requires a smaller aspect ratio (length over diameter).

Boron-doped diamond (BDD) film electrodes using Ta as substrates were employed for anodic oxidation of salicylic acid (SA). The effects of operational variables including initial concentration, current density, temperature and pH were examined. The results showed that BDD films deposited on the Ta substrates had high electrocatalytic activity for SA degradation. There was little effect of pH on SA degradation. The current efficiency (CE) was found to be dependent mainly on the initial SA concentration, current density and temperature. Chemical oxygen demand (COD) was reduced from 830 mg/L to 42 mg/L under a current density of 200 A/m² at 30 °C.

The effectiveness of using acoustical (sonochemical) reactor for degradation of linear alkylbenzen sulfonate (LAS) from aqueous solution was investigated. LASs are anionic surfactants, found in relatively high amounts in domestic and industrial wastewaters. In this study, experiments on LAS solution were performed using methylene blue active substances (MBAS) method. The effectiveness of acoustical processor reactor for LAS degradation is evaluated with emphasis on the effect of treatment time and initial LAS concentration. Experiments were performed at initial concentrations of 0.2, 0.5, 0.8 and 1.0 mg/L, acoustic frequency of 130 kHz, applied power of 500 W and temperature of 18 °C~20 °C. At the conditions involved, LAS degradation was found to increase with increasing sonochemical time. In addition, as the concentration increased, the LAS degradation rate decreased in the acoustical processor reactor.

Isolation of new bacterial strains and recognition of their metabolic activities are highly desirable for sustainability of natural ecosystems. Biodegradation of dimethyl phthalate (DMP) under anoxic conditions has been shown to occur as a series of sequential steps using strain CW-1 isolated from digested sludge of Sibao Wastewater Treatment Plant in Hangzhou, China. The microbial colony on LB medium was yellowish, 3~5 mm in diameter, convex in the center, and embedded in mucous externally. The individual cells of strain CW-1 are irregular rods, measuring (0.6~0.7)×(0.9~1.0) μm, V-shaped, with clubbed ends, Gram positive and without any filaments. 16S rDNA (1438 bp) sequence analysis showed that the strain was related to Arthrobacter sp. CW-1 and can degrade PAEs utilizing nitrate as electron acceptor, but cannot mineralize DMP completely. The degradation pathway was recommended as: dimethyl phthalate (DMP)→monomethyl phthalate (MMP)→phthalic acid (PA). DMP biodegradation was a first order reaction with degradation rate constant of 0.3033 d⁻¹ and half-life 2.25 d. The DMP conversion to PA by CW-1 could be described by using sequential kinetic model.

Considering that contaminated raw water mostly contains high Ammonia-N and a majority of water treatment plants use prechlorination process in China, efficiency of chloramines as a coagulant aid in enhancing coagulation was investigated by Jar stirring and pilot-scale tests, using Yellow River water containing high concentration of natural organic matters (NOM) and bromide in winter. The jar tests results showed that, compared with no preoxidation, preformed chloramine apparently decreased the turbidity of settled and filtered water with low dosage (2.0 mg/L), and the aid-coagulation efficiency was further enhanced with the increase of chlorine (Cl₂) to Ammonia-N (N) ratio. Pilot-scale studies indicated that, in comparison to the case without preoxidation, the turbidity removal efficiency of flotation and filtration effluent water was significantly improved, the particle counts of filtered water were decreased 63.4%, the average rate of filter head loss was reduced 18.2%, and filter run time was prolonged 15.7%. Therefore, chloramine preoxidation may substantially enhance the particle separation efficiency.

This paper deals with the study of a water quality forecast model through application of BP neural network technique and GUI (Graphical User Interfaces) function of MATLAB at Yuqiao reservoir in Tianjin. To overcome the shortcomings of traditional BP algorithm as being slow to converge and easy to reach extreme minimum value, the model adopts LM (Levenberg-Marquardt) algorithm to achieve a higher speed and a lower error rate. When factors affecting the study object are identified, the reservoir’s 2005 measured values are used as sample data to test the model. The number of neurons and the type of transfer functions in the hidden layer of the neural network are changed from time to time to achieve the best forecast results. Through simulation testing the model shows high efficiency in forecasting the water quality of the reservoir.

Due to pollution in second water supply system (SWSS), nine renovation alternative plans were proposed and comprehensive evaluations of different plan based on Analytical Hierarchy Process (AHP) were presented in this paper. Comparisons of advantages and disadvantages among the plans of SWSS renovations provided solid foundation for selecting the most appropriate plan for engineering projects. In addition, a mathematical model of the optimal combination of renovation plans has been set up and software Lingo was used to solve the model. As a case study, the paper analyzed 15 buildings in Tianjin City. After simulation of the SWSS renovation system, an optimal scheme was obtained, the result of which indicates that 10 out of those 15 buildings need be renovated in priority. The renovation plans selected for each building are the ones ranked higher in the comprehensive analysis. The analysis revealed that the optimal scheme, compared with two other randomly calculated ones, increased the percentage of service population by 19.6% and 13.6% respectively, which significantly improved social and economical benefits.

Bamboo was a popular material substituting for wood, especially for one-off commodity in China. In order to recover energy and materials from waste bamboo, the basic characteristics of bamboo pyrolysis were studied by a thermogravimetric analyzer. It implied that the reaction began at 190~210 °C, and the percentage of solid product deceased from about 25% to 17% when temperature ranged from 400 °C to 700 °C. A lab-scale fluidized-bed furnace was setup to research the detailed properties of gaseous, liquid and solid products respectively. When temperature increased from 400 °C to 700 °C, the mass percent of solid product decreased from 27% to 17% approximately, while that of syngas rose up from 19% to 35%. When temperature was about 500°C, the percentage of tar reached the top, about 31%. The mass balance of these experiments was about 93%~95%. It indicated that three reactions involved in the process: pyrolysis of exterior bamboo, pyrolysis of interior bamboo and secondary pyrolysis of heavy tar.

The dimensions and the materials type limit the performance of fuel cell. The increase of the temperature in electrodes and electrolyte of the cell, is due to the over potential of activation (transfer of load), the over potential Ohmic (resistance of polarization), the over potential of reaction (heat released by the chemical reaction) and the over potential of diffusion. In this paper, we studied the thermo-electrical performance of an intermediate temperature solid oxide fuel cell (IT-SOFC) with electrode supported. The aim of this work is to study this increasing temperature of a single cell of an IT-SOFC under the influence of the following parameters: heat sources, functioning temperature and voltages of the cell, geometric configuration and materials type. The equation of energy in one dimension is numerically resolved by using the method of finite volumes. A computing program (FORTRAN) is developed locally for this purpose in order to obtain fields of temperature in every element of the cell.

The solid oxide fuel cell (SOFC) is a nonlinear system that is hard to model by conventional methods. So far, most existing models are based on conversion laws, which are too complicated to be applied to design a control system. To facilitate a valid control strategy design, this paper tries to avoid the internal complexities and presents a modelling study of SOFC performance by using a radial basis function (RBF) neural network based on a genetic algorithm (GA). During the process of modelling, the GA aims to optimize the parameters of RBF neural networks and the optimum values are regarded as the initial values of the RBF neural network parameters. The validity and accuracy of modelling are tested by simulations, whose results reveal that it is feasible to establish the model of SOFC stack by using RBF neural networks identification based on the GA. Furthermore, it is possible to design an online controller of a SOFC stack based on this GA-RBF neural network identification model.

Mg-25 wt% Mg₂Ni composite was prepared by sintered method, hydrided at 613 K and then ball-milled with 1.5 wt% PdCl₂ additive for 51 h. The effects of PdCl₂ on the hydriding and dehydriding behavior of Mg-25 wt% Mg₂Ni composite were investigated. The absorption and desorption rate of the composite with PdCl₂ is fast and the hydrogen storage capacity is more than that of the composite without PdCl₂. The maximum hydrogen storage capacity reached 3.48 wt% at 373 K, and 5.05 wt% H at 453 K, respectively. The improvement of sorption and desorption kinetics is attributed to the catalytic effect of PdCl₂, and the grain refining and lattice strain introduced by ball milling.

In this work, rhamnolipid production was investigated using waste frying oil as the sole carbon source. By culture in shaking flasks, a naturally isolated strain synthesized rhamnolipid at concentration of 12.47 g/L and its mutant after treatment by UV light increased this productivity to 24.61 g/L. Fermentation was also conducted in a 50 L bioreactor and the productivity reached over 20 g/L. Hence, with a stable and high productive mutant strain, it could be feasible to reuse waste frying oil for rhamnolipid production on industrial scale.

Lovastatin production by Aspergillus terreus ATCC 20542 in solid-state fermentation (SSF) was studied. Various substrates were used to evaluate the ability of A. terreus to produce lovastatin. The results showed that either rice or wheat bran was suitable substrate for lovastatin production in SSF. The maximum yield of lovastatin (2.9 mg/g dry substrate) using rice as substrate was achieved after incubating for 11 d at the following optimized process parameters: 50%~60% initial moisture content, pH 5.5, incubation temperature 28 °C.