Prevention of RCF damage in curved track through development of the INFRA‐STAR two‐material rail

Results from the European 5th frame research project ‘INFRA‐STAR’ are presented. The goal of the project is to prevent rolling contact fatigue (RCF) and to reduce squeal noise in curves by applying an additional surface layer material on the top of the railhead, resulting in a two‐material rail. In INFRA‐STAR, a dynamic train–track interaction model is used to provide the contact forces. Wheel‐rail profiles, wheel‐rail friction, vehicle data, track data and operating conditions are included to calculate the wheel‐rail contact forces and spin moments, contact positions and load distributions in the contact patch. The contact pressure, friction coefficient, coating thickness, material properties of the coating and the rail material are used in finite element calculations and shakedown theory to calculate shakedown limits, which are then used to predict the RCF performance of the system. The paper details the work on theoretical modelling, twin disc testing, metallurgical research and field testing completed to date (August 2002, the project just passed midterm). The development of the surface layer application methods that are used, and the further objectives of the INFRA‐STAR project, are discussed.     

HIGH MANNURONATE ALGINATES AS BINDERS IN RESTRUCTURED BEEF

Three high mannuronate alginate types (Sobalg Fd 155, 176, and 275) were evaluated as binders in finely ground restructured beef (M. semitendinosus). Formulations with alginate levels (0.50%–1.25%) and calcium carbonate levels (0.10%–0.25%) were prepared, including the acidulant glucono-delta-lactone (0.80%). In addition, Sobalg Fd 176 was evaluated in a coarsely ground restructured product using the same raw materials and ingredient levels.
Among alginate types, the relatively high viscosity graded alginate, Sobalg Fd 176, resulted in the highest raw breaking strengths and lowest cooking loss (P < 0.05). When averaged across alginate types, increased raw breaking strengths were observed when the level of alginate was elevated, providing the calcium carbonate level was ≤ 0.15%. In the coarsely ground product using Sobalg Fd 176, cooked tensile strength ranged from 11.6 N to 17.9 N, corresponding to a satisfactory bind. In both finely and coarsely ground restructured samples, cooking loss was reduced when alginate levels were elevated, and pH increased as a function of calcium carbonate level (P < 0.05). This study demonstrates, that high mannuronate alginates, especially Sobalg Fd 176, can be used as binders in restructured beef products.     

Thermal Expansion in Air of Ceramic Oxides to 2200°C

Thermal-expansion measurements were made in an air atmosphere to 2200°C on polycrystalline single-phase ceramic oxides. Specimens were fabricated by hot-pressing, slip casting, and isostatic pressing. Magnesium oxide was tested in both air and argon; calcium oxide as well as magnesium aluminate and aluminum oxide specimens were tested in air. Specimens were characterized as to purity, thermal history, apparent density, grain size, and lattice parameter. It was determined that the coefficient of thermal expansion was not affected by changes in grain size or by fabrication techniques. All of the specimens tested in an air atmosphere showed weight and lattice parameter stability, whereas the magnesium oxide tested in argon did not. When tested in an air atmosphere, magnesium oxide, aluminum oxide, and magnesium aluminate spinel showed a permanent expansion with a decrease in density at temperatures well below their melting points.     

Lactose Crystallization from Whey Permeate in an Ethanol-Water Mixture

A 30% concentrated permeate of a whey ultrafiltration process was used for producing crystalline a-lactose monohydrate. Effect of pH (2.75–5.5 pH units) at solvent to solute ratio 10:1 v/w, agitation and seeding (0.004–0.02%) on rate of lactose crystallization were examined. Conditions which were favorable in terms of crystallized lactose yield, and time of crystallization were: pH 5.5, agitation with or without seeding and 22°C. The first-order reaction-rate constant for crystallization ranged from 0.0178 to 0.200 hr^?1 depending on conditions.     

Application of the prins reaction on oleic acid

The probable structure of the various components of oleic acid-formaldehyde adducts is discussed. The adducts are reduced to alcohols by high pressure hydrogenation with copper chromite as a catalyst. The new alcohols are distilled, analyzed and used for the preparation of various esters with carboxylic acids. The esters were evaluated as low temperature lubricant base stocks and low temperature plasticizers.     

Recent Advances in Minimal Heat Processing of Fish: Effects on Microbiological Activity and Safety

Thermal processing is one of the most common methods for achieving safe convenience fish products with an extended shelf life. Designing a thermal process for such products, typically in the range of 60–95 °C for 10 to 30 min, is challenging since the heat load required for inactivating target microorganisms may cause undesirable quality changes in the lipid and protein fraction. Concern about the safety of some fish products exists, particularly when considering the potential abuse caused by storage temperature. New methods that focus on minimal heating or rapid heating of fish products are therefore of vital importance. The main aim for new developments is to reduce the overall thermal load by reducing the temperature gradients in the product or by targeting specific potentially infected areas. In both cases, alternative technologies to conventional autoclaves, combi-steamers or water baths are used for enhanced heat transfer, thereby providing more rapid heating and avoiding unnecessarily high heat loads on part of the product. Dielectric heating, Shaka technology and surface pasteurisation are technologies that meet these approaches, and are now available for industrial applications. Minimal processing often relies on the use of multiple sub-lethal stresses or processes to achieve a similar level of microbial control such as that traditionally achieved by using a single lethal stress. Most minimally processed products require refrigerated storage and distribution to maintain food safety.     

TEXTURAL PARAMETERS IN COMPRESSION TESTING OF A GEL MADE FROM FRESH AND FROZEN FISH MINCE

The relation between deformability modulus and yield stress is evaluated in compression testing of a model product made from fresh and frozen stored mince of cod. The experiments were performed with a compression rate of 120 mm/min. Preliminary experiments showed decreasing values of yield stress when compression rates were below 50 mm/min. Two moduli were calculated from the slope of the compression curve; α₁, initially (small deformations) and α₂ in a linear part of the curve shortly before rupture of the gel. α₂ was linearly related to yield stress in gels of different water content, and in gels made from fresh and frozen raw material. α₁ showed different relations to yield stress depending on quality of the raw material.     

The role of electrical current mode in calcium carbonate deposition on conductive carbon nanofiber–epoxy coating

Calcium carbonate is one of the most common scaling minerals. In this paper we have used different electrical current modes (direct current [DC], pulsed DC, and alternating current [AC]) to control the amount, morphology, and distribution of calcium carbonate deposit on electroconductive epoxy/carbon nanofiber (CNF) coating. The effect of different current modes on surface scaling was visualized using scanning electron microscopy. It has been shown that both AC and DC anodic polarization limited scale deposition on epoxy/CNF coated surfaces, although the mechanisms of scale inhibition during AC and DC polarization were different. DC polarization of the coating at +2 V resulted in the smallest scale buildup without leading to coating degradation, while DC polarization at potentials as high as +5 V caused the coating to degrade. Interestingly, application of pulsed DC with high pulse frequency (50 Hz) inhibited the degradation. The type of current applied affected also the morphology of the precipitate at the cathode. The results presented in this work show, for the first time, how different modes of electrical current applied to electroconductive composite coatings can be used to control the morphology and distribution of calcium carbonate scale, and how the organic coating degradation at high polarization potentials can be avoided.