A GIS AND WEB-BASED DECISION SUPPORT TOOL FOR THE MANAGEMENT OF URBAN SOILS

Soils are fundamental to urban environmental quality. They have aesthetic and recreational functions in parks and gardens and contribute to the preservation of biodiversity. They also directly influence citizens' health. This paper describes the initial development of a decision support tool (DST) to appraise the urban soil resource and its valuable functions within a wide range of urban environments. It is aimed to provide assistance to local, national, and European authorities in the optimum planning and sustainable management of their soils resources. The DST is an integrated information technology system based on a spatially distributed environmental database management system of soil quality parameters and soil characteristics together with broader environmental factors. The integration is achieved through the implementation of the DST within the framework of a geographical information system coupled with risk assessment, pollution decay, and other models including the handling of “soft” data. The DST will be web-based, allowing wide access to all stakeholders and citizens, providing on-line forums for consultations, and exchange of information and feedback among stakeholders. It is designed to support true transparency in decision making at the local and international levels. The paper focuses specifically on the development of the system architecture of the DST.     

Relationship of Quality Characteristics of Peaches (cv. Loring) to Maturity

The effect of maturity and ripening on the quality characteristics of Loring peaches was determined. Size, weight, Minolta a values, sucrose, total sugar, soluble solids (SS) and SS/TA ratio of cv. Loring peaches increased significantly with increased degree of maturity of fruit. Firmness, titratable acidity (TA) and delayed light emission (DLE) decreased significantly with increased maturity grade. The fruit of grades 1 and 2 did not attain sensory characteristics similar to tree ripe fruit (grades 6 and 7). The fruit of those grades were less sweet and more sour than grades 3-7. The optimum maturity for harvesting Loring peaches for optimum quality was maturity grade 5.     

THE TEXTURE OF COD MUSCLE

Data on moisture, protein content and pH (after 24 h in ice post mortem) of the flesh of cod of different sizes, captured during several fishing expeditions from Aberdeen to northern fishing grounds in spring and autumn, have been examined in relation to the texture of the cooked material. It is concluded that large fish are slightly tougher than small fish, even when the pH is the same. In addition, the pH of large fish is often lower than that of small fish, so the relative toughness of large fish is enhanced. However, the size-pH relationship is clearly defined only in well-fed fish at certain times of the year. At other times, when food is scarce, the post-mortem pH of the muscle of all sizes of cod varies within wide limits, so that size no longer appears to influence the texture. Of the parameters studied, the post-mortem pH correlated best with the texture after cooking. Since fish with a high pH usually have a high water content, there was also a correlation between texture and moisture. However, the protein content seemed to exercise a negligible influence on texture, an unexpected finding considering that protein accounts for nearly all the ‘substance’ of white fish flesh after the water has been removed.     

Calculation of Activation Energy of Ionic Conductivity in Silica Glasses by Classical Methods

An equation for the activation energy of ionic conduction in silica glasses is developed. The approach uses the classical ideas of ionic crystal theory and elasticity theory. The equation finally derived involves the radius and valence of the modifier ion, the lattice constant of the glass, the electronic charge, the shear modulus, and three arbitrary parameters. Two of these parameters are shown to be related to the geometry of the silica network and are exactly determined from diffusion of gases in glass data. The other parameter is shown to be approximately numerically equal to the dielectric constant. he theory is compared with the experimental results of 140 glass compositions.     

THE GHANGING BREED STRUCTURE OF SCOTTISH DAIRY CATTLE

Changes in breed structure have taken place in the Scottish dairy herd set against a background of a 10-year decline in total cow and producer numbers. The detailed trends are discussed and related to insemination and milk recording statistics. The possibilities for further change are discussed as are the implications for cattle breeding and milk production in the next few years.     

A Review of:“Product Design with Plastics: a Practical Manual.” By Joseph B. Dym. (Industrial Press, 1983.) [Pp.297.] £22-50.

Correct formulation of the master production schedule is critically important for the optimization of the management of a production planning and control system. Most of the models described in the literature solve the problem in two separate sequential stages: lot sizing and then sequencing. This often produces an MPS which is not optimized or even not feasible. On the other hand, when the problem is tackled with models based on mixed integer linear programming, then dimensional constraints have to be respected which can limit the field of applications of the model itself.

A complete heuristic algorithm is presented in this paper which solves the problem of lot-sizing and sequencing in a single logic stage, together with the results of an extensive series of tests carried out to compare, in different types of production systems, the performances of the proposed heuristic and those of another algorithm taken from literature. The model concerns a single production line situation with relevant setup problems; on this production line component availability constraints are not considered (the model refers to mono-level bill of material products, but it can be applied also to the most critical level in multi-levels production systems).     

THE USE OF SPECULATION AND ANALYSIS IN THE DEVELOPMENT OF CORRELATIONS

Speculative analysis is shown to be effective Tor the development of asymptotes which are in turn useful for the development of correlating equations. Speculation is here defined as the selective elimination of variables among a complete set, or of terms in a model. The results of such speculation must be evaluated by comparison with experimental data and theoretical solutions. This procedure is illustrated for several processes of fluid flow and heat transfer. Guidelines are developed for its efficient application. Imprecision of the available data and their failure to extend to asymptotically large and small values is found to be a limiting factor in evaluating speculations and discriminating between competitive ones.