The Wreck of Amtrak's Sunset Limited: News Coverage of a Mass Transport Disaster

Using the 1993 crash of Amtrak's Sunset Limited in Mobile, Alabama, this study examines the safety education provided by seven newspapers. A total of 117 news stories were analysed for five primary themes: overall story category, passenger safety theme, train personnel safety theme, train safety theme and rescue safety. Sixty-three per cent were found to contain at least one safety theme paragraph within the larger story. A total of 631 paragraphs were identified as safety theme paragraphs, 32 per cent of which were passenger safety themes, 8 per cent were train personnel safety, 31 per cent were train safety and 29 per cent were rescue safety themes. As in previous research, safety themes rarely appeared alone; more often than not, a story contained a mixture of all themes. Some safety themes appeared more frequently than others, but overall, the safety themes present a complete view of the safety issues surrounding the crash.
Safety themes are embedded within a story framework which reflects the three stages of disaster news work. Images of normalcy tragically disrupted by the crash abound as do images of passengers escaping and aiding others. Disaster relief personnel and aviation officials are shown working to restore order and solve the mystery of the crash. Within this framework we can learn what to expect when a train crashes and what we might have to do in a similar situation.     

二氧化钛光催化降解处理染料废水

研究了TiO2的添加量,粒径大小,作用时间对3种染料废水脱色率的影响及TiO2薄膜对染料废水的处理效果。对于汽巴克染绿和直接大红染料溶液,适宜的TiO2添加量均为5g/L,紫外灯照射60min,其脱色率大于85％。对于阳离子红染料溶液,适宜的TiO2添加量为3g/L,其脱色率为83．5％。粒径小的TiO2作用效果优于粒径大的效果。在室温和适宜的TiO2添加量的条件下,随照射时间的延长,太阳光的光催化降解效果渐渐接近于紫外光的光催化降解效果。将TiO2薄膜固定在陶瓷睛上,有利于TiO2的重复使用。     

Socio-economic levels and environmental perception in a small town in Argentina

Summary In order to determine the environmental problems as perceived by the community of Luján (Province of Buenos Aires, Argentina), a survey was carried out. The relationship between environmental perception and socio-economic level was also studied. The most important problems reported by the community were the floods, which occur when the Luján river overflows its banks, and the contamination of this river as it flows through Luján city. Deficiencies in the tourist infrastructure were also considered to be serious. The least perceived problem was that of industrial air pollution. Positive correlations between environmental perception, socio-economic standing and levels of instruction were observed.Claudia Feijoó is a Lecturer in Ecology at the National University of Luján. Her research interests are in environmental perception and ecology of rivers and polluted waters. Prof. Fernando Momo is Professor of Ecology at the same University. His research interests are focused on theoretical ecology and ecological modelling, especially as applied to aquatic ecology.     

Evolution of biodegradation of deinking by-products used as alternative cover material

Deinking by-products (DBP) have been used as alternative cover material for landfills and mine tailings. Since DBP is biodegradable because of its high cellulose and hemicellulose content, a laboratory experimental program was performed to monitor the evolution of biodegradation and changes in the physico-chemical and geotechnical properties of DBP samples submitted to accelerated biodegradation for 1460 days at 38 degrees C. The evolution of gas and leachate production was monitored in terms of both quality and quantity, which allowed for the calculation of mass loss with time. Under the conditions of the tests (no load applied), 19.6% of the mass was lost as gas, whereas 6.1% was leached out. The results show that biodegradation did not significantly alter the compaction behavior of DBP. The void ratio and water content increased significantly, while the volume of the samples slightly decreased. This seem to indicate that the porous structure of the samples was no longer the same after 1460 d of accelerated biodegradation. A slight increase in the relative density indicates that the organic/inorganic matter ratio increased. The results of permeability tests performed with samples at various stages of biodegradation and at various confining stresses show that the saturated hydraulic conductivity of recompacted biodegraded DBP decreased from 7 x 10(-7)cm/s to approximately 2 x 10(-7)cm/s, as biodegradation advanced.     

Zinc accumulation in plant species indigenous to a Portuguese polluted site: relation with soil contamination

The levels of zinc accumulated by roots, stems, and leaves of two plant species, Rubus ulmifolius and Phragmites australis, indigenous to the banks of a stream in a Portuguese contaminated site were investigated in field conditions. R. ulmifolius, a plant for which studies on phytoremediation potential are scarce, dominated on the right side of the stream, while P. australis proliferated on the other bank. Heterogeneous Zn concentrations were found along the banks of the stream. Zn accumulation in both species occurred mainly in the roots, with poor translocation to the aboveground sections. R. ulmifolius presented Zn levels in the roots ranging from 142 to 563 mg kg(-1), in the stems from 35 to 110 mg kg(-1), and in the leaves from 45 to 91 mg kg(-1), vs. average soil total Zn concentrations varying from 526 to 957 mg kg(-1). P. australis showed Zn concentrations in the roots from 39 to 130 mg kg(-1), in the stems from 31 to 63 mg kg(-1), and in the leaves from 37 to 83 mg kg(-1), for the lower average soil total Zn levels of 138 to 452 mg kg(-1) found on the banks where they proliferated. Positive correlations were found between the soil total, available and extractable Zn fractions, and metal accumulation in the roots and leaves of R. ulmifolius and in the roots and stems of P. australis. The use of R. ulmifolius and P. australis for phytoextraction purposes does not appear as an effective method of metal removing, but these native metal tolerant plant species may be used to reduce the effects of soil contamination, avoiding further Zn transfer to other environmental compartments.     

Mathematical modelling of a composting process, and validation with experimental data

The present study aimed to develop a mathematical model of composting which, while not overlooking the fundamental principles of physical and microbiological chemistry, could be easily applied in practice and be validated by experimental data. The experimental results of the biological aerobic decomposition of a mixture consisting of rice and rice husks, could be explained in terms of the parameter aggregation model, assuming a set of pseudo-first-order reactions in series, in which a hydrolysis step is followed by a biochemical oxidative step with formation of compost, biomass and biological gases (CO2, O2). The corresponding kinetic parameters and their temperature dependence were determined. These parameters indicated that the hydrolysis step was always the slowest one, and, therefore, the overall rate-determining step. This is in substantial agreement with our experimental observations of a non-dependency of the overall rate on the oxygen concentration, and suggests that rather than using mesophilic and thermophilic bacteria and fungi for seeding or accelerating the process, adequate hydrolytic enzymes (or related micro-organisms) should be added, instead.     

Eucalyptus ESTs related to genes for oxidative stress

Oxidative stress generating active oxygen species has been proved to be one of the underlying agents causing tissue injury after the exposure of Eucalyptus (Eucalyptus spp.) plants to a wide variety of stress conditions. The objective of this study was to perform data mining to identify favorable genes and alleles associated with the enzyme systems superoxide dismutase, catalase, peroxidases, and glutathione S-transferase that are related to tolerance for environmental stresses and damage caused by pests, diseases, herbicides, and by weeds themselves. This was undertaken by using the eucalyptus expressed-sequence database (https//forests.esalq.usp.br). The alignment results between amino acid and nucleotide sequences indicated that the studied enzymes were adequately represented in the ESTs database of the FORESTs project.