Transcrystallisation in PP/flax composites and its effect on interfacial and mechanical properties

The effect of flax fibre reinforcement on the crystallisation behaviour of polypropylene (PP) was investigated using a hot-stage polarising optical microscope. To follow the crystallisation kinetics, crystallisation temperature and time were varied. At crystallisation temperatures between 130 and 138 °C the most uniform and thickest transcrystalline layers were formed. The effect of transcrystallisation on the interfacial shear strength (IFSS) in micro-composites was studied by the fibre pull-out test method. It was found that the IFSS of the PP/flax system is slightly decreased with the presence of a transcrystalline interphase. Finally, the influence of the formation of a transcrystalline zone on the macromechanical properties of compression moulded PP/flax composites was studied.     

Impact of plug-in hybrid electric vehicles on power systems with demand response and wind power

This paper uses a new unit commitment model which can simulate the interactions among plug-in hybrid electric vehicles (PHEVs), wind power, and demand response (DR). Four PHEV charging scenarios are simulated for the Illinois power system: (1) unconstrained charging, (2) 3-hour delayed constrained charging, (3) smart charging, and (4) smart charging with DR. The PHEV charging is assumed to be optimally controlled by the system operator in the latter two scenarios, along with load shifting and shaving enabled by DR programs. The simulation results show that optimally dispatching the PHEV charging load can significantly reduce the total operating cost of the system. With DR programs in place, the operating cost can be further reduced.     

Liquid CO2 droplet extraction from gases

Efficient mechanical separation of CO₂ from combustion effluent affects the utilization potential of high CO₂ producers such as coal. Novel mechanical separations of condensing CO₂ from gas flows need to be able to capture the small condensed droplets below the cyclone cut-off limit of 20 μm. We describe the thermodynamics, the energy costs and droplet formation of CO₂ phase separation from combustion effluent and natural gas. We report the first measurements of condensing CO₂ droplet sizes from gas. This shows that application of homogeneous condensation of CO₂ yields much smaller droplets in flue gas (N₂/CO₂) than from contaminated natural gas (CH₄/CO₂). These small droplets can only be efficiently removed at high throughputs using the novel centrifugal method we describe. Such mechanical separations are preferable to the current standard chemical methods because of the much lower environmental footprint.     

Characterization of rigid polyurethane foams containing microencapsulated Rubitherm? RT27. Part I

Rigid polyurethane foams (RPU foams) and phase change materials (PCMs) are widely used in buildings for thermal insulation and thermal storage, respectively. The combination of both materials could increase energy savings, leading to more energy efficient housing. In this work, PU foams were produced incorporating different percentages of microcapsules containing Rubitherm^? RT27. Microcapsules added to the foam had a high influence on the foaming process and also on the foam properties. It was observed that the increase of foam microcapsules content decreases the final foam height but increases its density and thermal energy storage (TES) capacity. On the other hand, an increase of the foam microcapsules content up to 5 wt% led to decrease the reduced compressive strength (RS) and modulus (RE) in 7 and 25%, respectively. Higher contents had a sharply negative impact on mechanical properties.     

Registering Landsat images by point matching

Image registration of Landsat Thematic Mapper scenes with translational and rotational differences is studied. Two major steps of image registration, control-point selection and control-point matching, are emphasized. In control-point selection, the properties that a good control point should satisfy are defined. Several potential control-point candidates are suggested, and methods are discussed for extracting them from the input image. In control-point matching, a relaxation algorithm proposed in the literature is improved by reducing its time complexity from O(n⁴) to O(n³ ), where n is the number of control points. The matching algorithm also uses a two-way matching concept which utilizes the inherent symmetry property of the point-matching problem. The robustness of the proposed algorithm was demonstrated through simulation experiments by evaluating a matching index. Experimental results on Landsat images show that the proposed method produces results comparable to those obtained by an experienced photointerpreter     

Role of the phase composition of tungsten containing hard alloys in the formation of a layer of titanium carbide in gas titanizing

Conclusions In gas titanizing of tungsten-containing hard alloys a continuous layer of titanium carbide forms on their surface; its composition, thickness, and microhardness depend on the phase composition of the alloy, in particular on the amount of cobalt phase.When hard alloys contain the phase (Ti, W)C, the thickness of the layer of titanium carbide increases.We discovered selective solubility of the solid solution (Ti, W)C in the cobalt phase in proportion to its decarburization during titanizing; this leads to the formation of ring structure of the grains of (Ti, W)C with higher titanium content on the periphery which, as is known [9], increases the wear resistance of hard alloys.Translated from Poroshkovaya Metallurgiya No. 7(319), pp. 74–79, July, 1989.     

Automation of test bed studies of coal cutting

Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 110–115, May–June, 1988.     

Eddy current solutions applicable to the problem of nondestructive inspection of flat and cylindrical surface layer

Nondestructive inspection of flat and long cylindrical metallic-surface layers is conveniently dealt with using the results of wave propagations in a one-dimensionally stratified medium. Analytical solutions for some special profiles are obtained, and perturbation technique is used to obtain results for more frequently encountered profiles.     

Average Interest Rate Caps

There exist a number of approximation methods for the price of average rate options, when the underlying asset is a currency or equity. Realistic pricing models for average interest rate caps based on interbank offered rates have not yet been published. In this paper we propose to adapt the methods of Levy (1992), Vorst (1992) and Rogers and Shi (1995) for average rate options to price average interest rate caps, and we compare their computational efficiencies. All three methods are very fast, compared to the Monte Carlo simulation. Two of them are fast enough for on-the-fly calculations. The underlying interest rate model we use is consistent with the observed term structure of the interest rate. Hence, the models developed here are suitable for practical implementation.     

Developments in plastics packaging for the transport of dangerous goods

Several interesting developments in plastics packagings and intermediate bulk containers (IBCs) for the transport of dangerous goods are of importance. Significant developments include the application of new materials and packaging concepts, the increasing re‐use of packaging and the possibility of the application of recycled material. How these developments have influenced or should influence the UN recommendations and regulations on the transport of dangerous goods is discussed. Further, the role of CEN and ISO standards, which are under development, is indicated. In this context, the European project CHEMPACK funded by the EC within the framework of the Standards, Measurements and Testing programme, is outlined. This project is executed in cooperation with raw materials manufacturers, packaging/IBC manufacturers and research institutes, and is coordinated by TNO. The aim of the project is to develop harmonized test methods and procedures for the assessment of the chemical compatibility of plastics packagings and IBCs. Copyright © 1999 John Wiley & Sons, Ltd.