Application of high silica zeolite ZSM-5 in a hybrid treatment process based on sequential adsorption and ozonation for VOCs elimination

In this study, a hydrophobic synthetic zeolite, namely ZSM-5 is chosen as an adsorbent/catalyst for toluene removal. Experimental results showed that toluene adsorption onto ZSM-5 was favourable, following a Langmuir adsorption isotherm model. ZSM-5 zeolite was regenerated using gaseous ozone at low temperature. Adsorbed toluene was oxidised, releasing mainly CO₂ and H₂O. Traces of oxidation by-products such as acetic acid and acetaldehyde were formed and remained adsorbed after the oxidativate regeneration with ozone. After four successive cycles of adsorption/ozonation, the adsorption efficiency was not affected (92%–99%). These results showed that volatile organic compound (VOC) removal by adsorption onto ZSM-5 zeolite followed by ozone regeneration could be used as a promising hybrid process for the control of VOC emissions in terms of efficiency.     

The Effect of Heat on the Physicochemical Properties of Bacteriophage MS2

The differences in physicochemical characteristics between infectious and non-infectious viral particles are poorly known. Even for heat, which is known as one of the most efficient treatments to inactivate enteric viruses, the global inactivation mechanisms have not been described yet. Such knowledge would help distinguish between both types of particles and therefore clarify the interpretation of the presence of viral genomes in food after heat treatment. In this study, we examined in particular the differences in electrostatic charge and hydrophobicity between the two particle types. MS2 phage, a common surrogate for enteric viruses, was used as a model virus. The heat-induced inactivation process of the infectious phages caused hydrophobic domains to be transiently exposed and their charge to become less negative. The particles also became progressively permeable to small molecules such as SYPRO Orange dye. The presence of non-infectious phage particles in which the genome was not accessible to RNases has been clearly demonstrated. These observations were done for MS2 phages exposed to a temperature of 60 °C. When exposed to a temperature higher than their critical temperature (72 °C), the particles were disrupted and the genome became available for RNases. At lower temperatures, 60 °C in this study, the transient expression of hydrophobic domains of remaining infectious phages appeared as an interesting parameter for improving their specific detection.     

Persistent near-bottom aggregations of mesopelagic animals along the North Carolina and Virginia continental slopes

Submersible observations during four missions over the North Carolina and Virginia continental slopes (184–900 m) documented the occurrence of large aggregations of mesopelagic fishes and macronektonic invertebrates near or on the bottom. Aggregated mesopelagics formed a layer up to tens of meters deep positioned from a few centimeters to 20 m, usually <10 m, above the substrate. Aggregations were numerically dominated by microvores, notably the myctophid fish Ceratoscopelus maderensis and the penaeid shrimp Sergestes arcticus. Consistently present but in relatively lower numbers, were mesopelagic predators, including the paralepidids Notolepis rissoi and Lestidium atlanticum, the eel Nemichthys scolopaceus, the stomiid fishes Chauliodus sloani and Stomias boa ferox, and squids Illex spp. Near-bottom aggregations do not appear to be an artifact due to attraction to the submersible. Based on submersible observations in three areas in 4 years spanning a decade, near-bottom aggregations of midwater organisms appear to be a geographically widespread and persistent phenomenon along the continental slope of the southeastern US Aggregations may exploit areas of enhanced food resources at the bottom.     

FUNCTIONAL SIGNIFICANCE OF SPECIES COMPOSITION IN RIPARIAN PLANT COMMUNITIES1

ABSTRACT: This paper analyzes the spatial patterns of plant species richness observed in 1989 and in 1999 alongside the Adour River (Southwest France), focussing on: (1) upstream‐to‐down‐stream changes, (2) mid‐term changes, and (3) differences in observed patterns among various plant functional groups. The purpose of the research was to analyze how the proportions of invading species and/or ruderal species within riparian corridors can be related to regional environmental settings. About half of native and exotic species were ruderals. However, the proportion of competitors was higher within the native pool. No correlation was found between exotic and native functional groups. The longitudinal distribution of native and exotic ruderal species were correlated together, but they were not correlated with the total species richness. Converse to observations at the local scale in other studies, these patterns seem to be driven more by factors co‐varying with the size of the river and by climatic factors than by hydrological disturbance‐related factors. The role of the various plant groups studied and potential consequences on ecosystem function are discussed in the context of an increasing susceptibility of our ripanan corridors to invasions by nonriparian species. Management perspectives are discussed for the purpose of biodiversity conservation.     

Avoiding cultural trauma: climate change and social inertia

ABSTRACT

The failure of societies to respond in a concerted, meaningful way to climate change is a core concern of the social science climate literature. Existing explanations of social inertia display little coherence. Here, a theoretical approach is suggested that integrates disparate perspectives on social inertia regarding climate change. Climate change constitutes a potential cultural trauma. The threat of cultural trauma is met with resistance and attempts to restore and maintain the status quo. Thus, efforts to avoid large-scale social changes associated with climate change constitute an effort to avoid cultural trauma, and result in social inertia regarding climate change at individual, institutional, and societal levels. Existing approaches to social inertia are reviewed. An intellectual framework utilizing the work of Pierre Bourdieu is proposed to integrate these different levels of social interaction. Social processes that maintain social order and thus avoid cultural trauma create social inertia regarding climate change.     

Musculoskeletal Symptoms in Two Plants in the Electrical Sector

The study consisted of describing, using a questionnaire, the musculoskeletal symptoms in two industries in the electrical sector. The questionnaire was distributed to more than 600 workers in the two industries. The questionnaire described four types of variables: usual population data (age, gender, experience, etc.), certain work variables, the regions of the body affected in the past 12 months and in the past 7 days, and the severity of the symptoms. Ten variables were used to provide a symptom severity index. In the two plants, the women reported more frequent and more serious problems than the men and the least experienced workers were the most affected. In Plant 1, the questionnaire pinpointed two work sectors, whereas in Plant 2, the problems were found not to be concentrated in a few sectors, but distributed among different jobs throughout the entire plant.