Supply Chain Management in Food Chains: Improving Performance by Reducing Uncertainty

This paper investigates the impact of Supply Chain Management on logistical performance indicators in food supply chains. From a review of quantitative and more qualitative managerial literature, we believe that Supply Chain Management should be concerned with the reduction or even elimination of uncertainties to improve the performance of the chain. The following clusters of sources of uncertainty are identified: order forecast horizon, input data, administrative and decision processes and inherent uncertainties. For each source of uncertainty, several improvement principles are identified. A case study was conducted in a food chain in which a simulation model helped quantify the effects of alternative configurations and operational management concepts. By comparing this simulation study with a pilot study, the model is validated against real data, and organisational consequences are identified. The results of the case study suggest that reduction of uncertainties can improve service levels significantly, although current supply chain configurations restrict possible benefits. The availability of real-time information systems is found to be a requirement for obtaining efficient and effective Supply Chain Management concepts.     

Optimization of subtractive-transformative hybrid processes supported by the technological heredity concept

This paper presents the optimization procedure of a hybrid removal-forming type process based on the minimum energy consumption and demanded surface roughness which is supported by the analysis of transformation of the surface and sublayer properties termed as the technological heredity. The experimental investigation covers an alloy steel hardened to 35 HRC and 55 HRC which was initially turned using coated carbide and CBN tools and subsequently burnished to produce surfaces with Ra roughness parameter of about 0.15 μm. The modifications of the initial surface profiles, microstructure and microhardness of the sublayer were determined and relevant technological limits are selected.     

The corrosion behaviour of NiAl in Molten Carbonate at 650°C

In Molten Carbonate Fuel Cells (MCFC) the separator plates in a stack are exposed to severe conditions. The normal operating temperature of a MCFC is 650°C, while the electrolyte consists of an eutectic mixture of 62/38 Li₂CO₃/K₂CO₃. On one side the separator plate material is in contact with a reducing atmosphere and on the other side it is an oxidising atmosphere. Due to the application of a wet seal the material is also in contact with the molten carbonate. A wide range of materials is therefore being investigated to enable a justified materials selection either as base material or as coating. NiAl is one of the investigated materials, which has promising properties, due to the possible formation of a protective oxide LiAlO₂ layer. A comparison will be made with data available for pure Ni, with special emphasis on the protective character of the oxide layer based on quasi-stationary polarisation curves, exposure tests at open circuit potential and quenching experiments, incorporating earlier published results obtained on Ni with impedance measurements. All experiments were performed in molten carbonate, while the gas composition over the melt was 64% H₂, 16% CO₂, and 20% H₂O.     

Solidification of thermoviscoelastic melts. Part 3: Effects of mold surface temperature differences on warpage and residual stresses

The solidification of a molten layer of amorphous thermoplastic between cooled parallel plates is used to model the mechanics of part warpage in the injection-molding process. Flow effects are neglected, and a thermorheologically simple thermoviscoelastic material model is assumed. The model allows material to be added to fill the space created by the pressure applied during solidification so that this model can be used to assess packing-pressure effects in injection molding. Parametric results are presented on the effects of the mold temperatures and the packing pressure—the pressure applied during solidification to counteract the effects of volumetric shrinkage of the thermoplastic—on the in-plane and through-thickness shrinkages, on warpage, and on residual stresses in plaque-like geometries. The packing pressure is shown to have a significant effect on part warpage. While the results are presented in terms of normalized variables based on the properties of bisphenol-A polycarbonate, they can be interpreted for other amorphous thermoplastics, such as modified polyphenylene oxide, polyetherimide, and acrylonitrile-butadiene-styrene.     

Structural and Physicochemical Changes of Potato Starch Along Periodate Oxidation

Dialdehyde starches were prepared by oxidation with periodate. The influence of the degree of oxidation of the dialdehyde starch on its microstructural and physicochemical properties such as crystallinity, granular structure, complexing capacity with iodine and lysolecithine and water absorption are discussed. Oxidation appears to cause a gradual decrease of any microstructure, meanwhile water absorption is observed to be maximal at intermediate degrees of oxidation. A structure-swelling relationship has been developed and compared with the washing efficiency during purification.     

A new technique for the calculation and 3D visualisation of magnetic complexities on solar satellite images

In this paper, we introduce two novel models for processing real-life satellite images to quantify and then visualise their magnetic structures in 3D. We believe this multidisciplinary work is a real convergence between image processing, 3D visualisation and solar physics. The first model aims to calculate the value of the magnetic complexity in active regions and the solar disk. A series of experiments are carried out using this model and a relationship has been indentified between the calculated magnetic complexity values and solar flare events. The second model aims to visualise the calculated magnetic complexities in 3D colour maps in order to identify the locations of eruptive regions on the Sun. Both models demonstrate promising results and they can be potentially used in the fields of solar imaging, space weather and solar flare prediction and forecasting.     

Contrast of displays on the retina

Abstract— When the eye projects an image on the retina, contrast degradation takes place because of stray light in the eye. This letter shows that for a 24 × 18° display, the maximum achievable retinal contrast for a 4 × 4 checkerboard image is approximately 80:1 for young persons, going down to approximately 37:1 for a 70‐year‐old person. This information is important for both display consumers and manufacturers because it puts the display contrast specification into perspective and may affect the contrast design target of a display system.     

A view of the relation between the continuum theory of lattice defects and non-euclidean geometry in the linear approximation

A view is presented of the relation between the continuum theory of defects in crystals and the mathematical theory of non-metric, non-Riemannian geometry. Both theories are treated in the linear approximation. The lattice defects consist of disclinations, dislocations, and extra-matter, which are identified with the following three important tensors from non-Euclidean geometry: the Riemann-Christoffel curvature tensor, the Cartan torsion tensor and the non-metric Q-tensor. The correspondence between the two theories is established by finding a relation between the coefficients of linear connection of non-Euclidean geometry and the elastic strain, bend-twist, and quasi-plastic strain of defect theory. The definitions of the important tensors from non-Euclidean geometry then generally correspond to the field equations of defect theory. The identities for the curvature tensor generally correspond to the continuity equations of defect theory. The relation to the conventional formulation of defect theory is pointed out. Two examples are given to illustrate the concepts of the paper. One example is related to the deformations associated with constant dislocation distribution and the other to the deformations of a constant disclination distribution.     

Experimental set-up for measuring diffusive and advective transport of radon through building materials

This study describes an approach for measuring and modelling diffusive and advective transport of radon through building materials. The goal of these measurements and model calculations is to improve our understanding concerning the factors influencing the transport of radon through building materials. To reach this goal, a number of experiments have to be conducted. These experiments, including measurements in a large cylinder for creating diffusive and advective transport of radon under controlled, 'dwelling-like' conditions, are described here and the initial results are presented. A better understanding about the transport of radon through building materials will lead to more effective ways to decrease or to prevent the entrance of radon into dwellings.