Solid waste management in urban areas: Development and application of a decision support system

A decision support system (DSS) developed to assist the planner in decisions concerning the overall management of solid waste at a municipal scale is described. The DSS allows to plan the optimal number of landfills and treatment plants, and to determine the optimal quantities and the characteristics of the refuse that has to be sent to treatment plants, to landfills and to recycling. The application of the DSS is based on the solution of a constrained non-linear optimization problem. Various classes of constraints have been introduced in the problem formulation, taking into account the regulations about the minimum requirements for recycling, incineration process requirements, sanitary landfill conservation, and mass balance. The cost function to be minimized includes recycling, transportation and maintenance costs. The DSS has been tested on the municipality of Genova, Italy, and the results obtained are presented.     

Ecology of the mind and educational research: Chemistry,the universal language of nature

Summary The authors advocate the need for a new approach to chemistry, using educational research to permit a fuller appreciation of the functions of the mind and a better understanding of natural processes. Such studies will, the authors believe, clarify the true relationships between energy, matter and information. Their integration, within a conceptually unitary whole, should allow a wider and more fruitful interpretation of reality. An attempt is made to understand the preferential orientation of bond-electrons that give order to a molecular formation, in terms of a tentative reinterpretation of chemistry as a universal language of nature.Dr Paolo Manzelli, senior author of this paper, is Professor in the Department of Chemistry at the University of Florence and Executive Secretary to the International Committee for the Promotion of Advanced Educational Research (Capire). John Eaton, until very recently Head of Education and Media Studies at Farnborough College of Technology, Hants; is now Vice Principal at East Herts College, Broxbourne, Herts, UK.     

The modelling of pool vaporization

This paper describes a mathematical model which calculates the time dependencies of the flow rate and composition of the vapour emerging from a pool. A large variety of accidental cases can be covered: continuous or instantaneous spills, on confined or unconfined ground, ideal or non-ideal liquid mixtures in boiling or evaporating conditions. The boiling, when present, is modelled through an equation system comprising the Rachford-Rice relation and the energy balance of the pool, which is assumed to be well-mixed. In the case of a volatile pool, interfacial mass rates are determined taking into account the Stefan flux, and the thermal resistance inside the liquid phase is also considered. In all situations, the energy balance includes the contribution of ground, sun and air. Known experimental data have been used to validate the model.     

APPROACHES TO MULTIVARIATE MODELING OF WATER RESOURCES TIME SERIES1

ABSTRACT: Alternative approaches suggested for modeling multiseries of water resources systems are reviewed and compared. Most approaches fall within the general framework of multivariate ARMA models. Formal modeling procedures suggest a three-stage iterative process, namely: model identification, parameter estimation and diagnostic checks. Although a number of statistical tools are already available to follow such modeling process, in general, it is not an easy task, especially if high order vector ARMA models are used. However, simpler ARMA models such as the contemporaneous and the transfer-function models may be sufficient for most applications in water resources. Two examples of modeling bivariate and trivariate streamflow series are included. Alternative modeling procedures are used and compared by using data generation techniques. The results obtained suggest that low order models, as well as contemporaneous ARMA models, reproduce quite well the main statistical characteristics of the time series analyzed. It is assumed that the same conclusions apply for most water resources time series.     

Gauging the societal impacts of natural disasters using a capability approach

There is a widely acknowledged need for a single composite index that provides a comprehensive picture of the societal impact of disasters. A composite index combines and logically organizes important information policy‐makers need to allocate resources for the recovery from natural disasters; it can also inform hazard mitigation strategies. This paper develops a Disaster Impact Index (DII) to gauge the societal impact of disasters on the basis of the changes in individuals’ capabilities. The DII can be interpreted as the disaster impact per capita. Capabilities are dimensions of individual well‐being and refer to the genuine opportunities individuals have to achieve valuable states and activities (such as being adequately nourished or being mobile). After discussing the steps required to construct the DII, this article computes and compares the DIIs for two earthquakes of similar magnitude in two societies at different levels of development and of two disasters (earthquake and wind storm) in the same society.     

mtDNA control region and D-HPLC analysis: a method to evaluate the mating system in Syngnathidae (Teleostei)

Mitochondrial DNA (mtDNA) has been used extensively in animals for phylogenetic and population studies but it has been applied only occasionally to mating systems analysis, where nuclear markers are usually preferred. We used denaturing-high performance liquid chromatography (D-HPLC) to detect mitochondrial DNA polymorphisms to assess the genetic mating system in Syngnathus abaster. Our study of ten pregnant males, revealed polygyny in 30% of the males, who carried embryos originating from multiple females. In addition, 30% of the pregnant males carried embryos with the same mitochondrial haplotype. This is not sufficient to demonstrate polyandry but allows a rapid selection and a reduced sample size for further studies. In conclusion, the proposed technique is time- and cost-effective, allows the certain identification of polygyny and provides useful information to study polyandry.     

Sperm removal and ejaculate size correlate with chelae asymmetry in a freshwater crayfish species

Asymmetry in traits of sexual relevance may impair copulation behaviour and sexual performance of males, ultimately resulting in a fitness cost. Freshwater crayfish males use chelae, a sexually selected trait, to secure and position the female prior to and during mating. Thus, a relatively large chelae asymmetry, resulting from accidental loss and regeneration of one cheliped after autotomy, could have great consequences for male sexual behaviour. We studied copulatory behaviour and sperm expenditure of males paired to a mated female in Austropotamobius italicus, a freshwater crayfish species where both male and female mate multiply and where last-mating males are able to actively remove previously deposited sperm. We aimed at assessing whether male sperm removal and expenditure varied according to sperm allocated by first-mating males, and according to copulation behaviour and phenotypic traits (carapace length, chelae length and relative chelae asymmetry) of second-mating males. Second-mating males did not adjust their ejaculate size in relation to first-mating male ejaculate, nor to the first-mating male’s sperm removed. Moreover, the amount of sperm removed by second-mating males increased with increasing first-mating males ejaculate size, and first-mating male sperm remaining after removal did not correlate with the original first-mating male ejaculate size. Interestingly, the amount of sperm removed by second-mating males decreased with increasing relative chelae asymmetry, while increasing with male body size. However, second-mating (but not first-mating) asymmetric-clawed males produced larger ejaculates than symmetric-clawed ones. Importantly, the proportion of second-mating male sperm remaining after the two matings did not vary with relative chelae asymmetry nor with body size of second-mating males. Thus, small, asymmetric-clawed crayfish males appear to adopt sperm allocation tactics that allow them to fully compensate for their inferior sperm removal ability.     

Tributyltin chloride disrupts aortic vascular reactivity and increases reactive oxygen species production in female rats

Environmental Science and Pollution Research - Organotin compounds, such as tributyltin (TBT), are environment contaminants that induce bioaccumulation and have potential toxic effects on marine...