Adsorption of cadmium by sulphur dioxide treated activated carbon

Merck carbon (1.5 mm) was treated in three ways: heating from ambient temperature to 900 degrees C in SO(2); treatment at ambient temperature in SO(2); or successive treatments in SO(2) and H(2)S at ambient temperature. All samples were then characterised and tested as adsorbents of Cd(2+) from aqueous solution. The characterisation was in terms of composition by effecting ultimate and proximate analyses and also of textural properties by N(2) adsorption at -196 degrees C. Kinetics and extent of the adsorption process of Cd(2+) were studied at 25 and 45 degrees C at pH of the Cd(2+) solution (i.e., 6.2) and at 25 degrees C also at pH 2.0. The various treatments of the starting carbon had no significant effect on the kinetics of the adsorption of Cd(2+), but increased its adsorption capacity. The most effective treatment was heating to 900 degrees C, the adsorption in this case being 70.3% more than that of the starting carbon. The adsorption increased at 45 degrees C but decreased at pH 2.0 when compared to adsorption at 25 degrees C and pH 6.2, respectively.     

A statistical approach to estimate state variables in flow-accelerated corrosion problems

Sequential Monte Carlo or Particle Filter Methods have been widely used to deal with sequential Bayesian inference problems in several fields of knowledge. This technique involves approximation of probability sequences distributions of interest, by means of a large set of random samples, i.e. particles that are propagated along time with a simple Sampling Importance distribution, SI. A re-sampling technique is also used to improve the predictive probability. In this study, a methodology is proposed: apply the Bayesian filters to a state estimation problem involving the corrosion amount-time in a contraction–expansion geometry with the aid of Computational Fluid Dynamics to improve the accuracy of the results. The following filters were applied and compared: Sampling Importance Re-sampling filter (SIR filter) and Auxiliary Sampling Importance Re-sampling filter (ASIR filter). The corrosion model adopted is based on a double resistance due to the oxygen diffusion towards the wall through the hydrodynamic boundary layer and the oxide layer. Mass loss data over time are obtained from the literature to compare corrosion rates. Also, the influence of the corrosion products in rates of corrosion is discussed . Best results in corrosion damage estimation were obtained using the ASIR filter.     

微机测控技术在干式变压器试验中的应用

概述了干式变压器微机测试系统的特点，着重介绍了该系统在损耗试验和感应耐压试验中的应用情况。     

Computer arithmetic for probability distribution variables

The uncertainty in the variables and functions in computer simulations can be quantified by probability distributions and the correlations between the variables. We augment the standard computer arithmetic operations and the interval arithmetic approach to include probability distribution variable (PDV) as a basic data type. Probability distribution variable is a random variable that is usually characterized by generalized probabilistic discretization. The correlations or dependencies between PDVs that arise in a computation are automatically calculated and tracked. These correlations are used by the computer arithmetic rules to achieve the convergent approximation of the probability distribution function of a PDV and to guarantee that the derived bounds include the true solution. In many calculations, the calculated uncertainty bounds for PDVs are much tighter than they would have been had the dependencies been ignored. We describe the new PDV Arithmetic and verify the effectiveness of the approach to account for the creation and propagation of uncertainties in a computer program due to uncertainties in the initial data.     

A (somewhat) new solution to the variable binding problem

To perform automatic, unconscious inference, the human brain must solve the binding problem by correctly grouping properties with objects. Temporal binding models like SHRUTI already suggest much of how this might be done in a connectionist and localist way by using temporal synchrony. We propose a set of alternatives to temporal synchrony mechanisms that instead use short signatures. This serves two functions: it allows us to explore an additional biologically plausible alternative, and it allows us to extend and improve the capabilities of these models. These extensions model the human ability to both perform unification and handle multiple instantiations of logical terms. To verify our model's feasibility, we simulate it with a computer system modeling simple, neuron-like computations.     

Sketch-based warping of RGBN images

While current image deformation methods are careful in making the new geometry seem right, little attention has been given to the photometric aspects. We introduce a deformation method that results in coherently illuminated objects. For this task, we use RGBN images to support a relighting step integrated in a sketch-based deformation method. We warp not only colors but also normals. Normal warping requires smooth warping fields. We use sketches to specify sparse warping samples and impose additional constraints for region of interest control. To satisfy these new constraints, we present a novel image warping method based on Hermite–Birkhoff interpolation with radial basis functions that results in a smooth warping field. We also use sketches to help the system identify both lighting conditions and material from single images. We present results with RGBN images from different sources, including photometric stereo, synthetic images, and photographs.     

Physical and mechanical properties of unsaturated polyester resin matrix from recycled PET (based PG) with corn straw fiber

In this study, composites of unsaturated polyester resin (UPR), synthesized from recycled polyethylene terephthalate (PET), with 10 to 40% in volume of corn straw fiber (CSF), were elaborated and studied the effect of fiber content on their physical and mechanical properties. The content of cellulose (48.97%), hemicellulose (24.06%), and lignin (6.59%) were determined by chemical characterization of CSF. The characteristic bonds of the UPR were identified as a cross-linking network between the styrene monomer (ST) and the unsaturated polyester (UP) through FTIR. Two decomposition stages were observed by TGA–DTG. The results of physical and mechanical properties showed that as the fiber content increased in the UPR, the water absorption increased (0.6% to 2.56%), on the other hand, the density (1218.23 to 1150.28 kg/m³), flexural strength (50.58 to 26.98 MPa), flexural modulus (2.66 to 2.29 GPa), tensile strength (8.62 to 3.65 MPa), tensile modulus (1.18 to 0.43 GPa), and hardness (81.67 to 65.67 Shore D), they decreased. SEM analysis showed some defects in the fiber distribution in the UPR, which affected the mechanical properties of the composites. This research contributes to the development of new material from use of two waste materials for the benefit of the environment.     

Improving IT effectiveness through software process assessment

This paper provides some answers to the frequently asked question: what proof is there that process management gives measurable benefit in practice? We report the results of an improvement programme that is helping to improve the effectiveness of Scotland's IT community. This programme is currently operating in over 20 organizations and uses software process assessment as a key element. The majority of organizations have been on the programme for over a year and we have found that benefits can be obtained as early as six months from the outset of an assessment-based improvement programme. Using the experience of working with these organizations, we discuss how to set up an improvement programme and define the roles, responsibilities and critical factors that we have found successful.     

Viscous and Aeroelastic Effects on Wind Turbine Blades. The VISCEL Project. Part II: Aeroelastic Stability Investigations

The recent introduction of ever larger wind turbines poses new challenges with regard to understanding the mechanisms of unsteady flow–structure interaction. An important aspect of the problem is the aeroelastic stability of the wind turbine blades, especially in the case of combined flap/lead–lag vibrations in the stall regime. Given the limited experimental information available in this field, the use of CFD techniques and state‐of‐the‐art viscous flow solvers provides an invaluable alternative towards the identification of the underlying physics and the development and validation of sound engineering‐type aeroelastic models. Navier–Stokes‐based aeroelastic stability analysis of individual blade sections subjected to combined pitch/flap or flap/lead–lag motion has been attempted by the present consortium in the framework of the concluded VISCEL JOR3‐CT98‐0208 Joule III project. Copyright © 2003 John Wiley & Sons, Ltd.