Strategic appraisal of energy models for Mozambique

The needs that an energy supply system must meet are constantly changing, due to technological, social and political reasons. Effective energy planning is a dynamic process that is repeated periodically and adjusts to changing conditions. Energy decision makers and planners are no longer able to rely on inductive decision making since they have to investigate the effect of various decision parameters and possible future changes. To help in this process, models have been developed where estimates of future load growth, candidate power plants, fuels and other key factors can be introduced, from which the planners can evaluate decision parameters and the available alternatives. The paper presents the different methodologies and practices that are used by 11 energy models for energy demand forecasting, supply side management and generation expansion planning, demand side management and integrated resource planning. The paper concludes to the presentation of a strategic appraisal of the examined energy models appropriate for energy planning in Mozambique. Three models are proposed for conducting demand forecasting, generation expansion planning and demand side management. Copyright © 2002 John Wiley & Sons, Ltd.     

Calcium Phosphate Biomaterials: An Update

1Introduction Archaeologicalfindingsdatingbacktothe4thcentury BCshowedthatmissinghumanteethhavebeenreplaced bymaterialswhichincluded:animalteeth,coral,shells,ivory(elephanttusk),wood,andmetals[1].Inmodern times,autografts(boneobtainedfromanothersiteinthe …     

A generalization of Vidyasagar's theorem on stabilizability using state detection

In this paper we generalize the Vidyasagar's well known theorem on the local stabilizability problem of nonlinear systems using state detection [11]. Our purpose is to prove that if a system is weakly detectable and stabilizable by means of a continuous state feedback u = γ(x), for which no differentiability assumption is imposed, then the system is also stabilized by the law u = γ(z), where z is the output of a weak detector for the state x. The result above is applicable to several cases not covered by other works.     

Comparisons of taste perceptions and preferences of Japanese and Australian consumers: overview and implications for cross-cultural sensory research

A program of research that compared the taste perceptions and preferences of Japanese and Australian consumer panels is reviewed from the point of view of the general issues that have emerged. These studies revealed few cross-cultural differences in the perceptions of the panels, implicating an important role for dietary experience in differences in preference. There was also little evidence for cross-cultural influences on panellists' assessment behaviour, such as scale usage. Studies of predominantly sweet and salty foods from both Australia and Japan illustrated the importance of familiarity with the overall product as an influence on the assessment of individual sensory characteristics. Subsequent attempts to overcome this influence by comparing cross-cultural responses to the manipulation of tastes within foods common to both cultures revealed no differences in the optimum tastant level within each of the foods. The implications of these studies for future cross-cultural research is addressed, and it is argued that future studies need to develop methods for determining the acceptability of relatively novel foods specifically developed for export markets, and also to address the complexity of food preferences from the point of view of both sensory and non-sensory influences.     

Response spectrum analysis of piping systems with elastic-plastic gap supports

A new seismic support device and its application in piping systems is described. The device, E-BAR (patented), can be cost effectively used for snubber replacement programs, mitigation of hydraulic transients, pipe whip and as a thermal stop. The device has pre-set gaps to allow free thermal movement. During a seismic or other dynamic load event, if the pipe movement exceeds the gap dimension, the device acts as an elastic or elastic-plastic restraint. The device also has a unique design feature for not exceeding the restraint force beyond a specified limit design value. To analyze piping systems with gap supports having elastic-plastic characteristics, modal analysis procedures for both response spectrum and time history methods are developed. The comparison of responses obtained from the procedures with nonlinear time history analysis and test results available in the literature shows excellent correlation. A pilot program conducted for snubber replacement with E-BARs demonstrates that the limit force feature of E-BAR makes them very attractive for snubber replacement. This is because a particular E-BAR with a specified limit design force can be selected, such that, the E-BAR replacing the snubber does not require any modifications be made to the existing support steel and hardware.     

Algorithms for Scheduling Multi-Level Just-In-Time Production Systems

Many companies are using Just-In-Time (JIT) control systems in their mixed-model multi-level production facilities. When scheduling these facilities the most important objective is to keep a constant rate of usage for every part used by the system. In this paper a mathematical model for scheduling these facilities is studied and techniques for determining good schedules are developed. Procedures for solving very large problems are given.