Speciation of the semivolatile hydrocarbon engine emissions from sunflower biodiesel

Biodiesel fuel is a very attractive alternative to conventional fuel and its effects in the engine performance and regulated emissions have been widely studied. However, the impact on unregulated individual compounds or chemical characteristics of exhaust emissions is not fully characterized. In this paper, the semivolatile fractions of the exhaust emissions of biodiesel blends and conventional fuel have been speciated. The results show great differences between the compounds emitted, especially regarding oxygenated and aromatic species. Likewise, there is a clear relationship between speciated hydrocarbons and other important emissions such as total hydrocarbons (HC), particulate matter (PM), volatile organic fraction (VOF) and mean particle diameter (Dm) of PM.     

Effect of the exposure angle in the corrosion rate of plain carbon steel in a marine atmosphere

This investigation aims to analyse the effect of the exposure angle on the corrosion rate of mild steel. Test samples were exposed to a marine environment at 0°, 30°, 45° and 90° inclination. To determine the effects of contaminants on the protective characteristics of the rusts, Cl and SO₂ contents in the atmosphere as well as SEM-EDX analyses and polarisation curves on the weathered samples were performed. Results demonstrated that the exposure angle influences the corrosion rate, as also the morphology of the rust, but with no effect on rust composition.     

Good Enough is Good Enough: Overcoming Disaster Response Organizations’ Slow Social Media Data Adoption

Organizations that respond to disasters hold unreasonable standards for data arising from technology-enabled citizen contributions. This has strong negative potential for the ability of these responding organizations to incorporate these data into appropriate decision points. We argue that the landscape of the use of social media data in crisis response is varied, with pockets of use and acceptance among organizations. In this paper we present findings from interviews conducted with representatives from large international disaster response organizations concerning their use of social media data in crisis response. We found that emergency responders already operate with less than reliable, or “good enough,” information in offline practice, and that social media data are useful to responders, but only in specific crisis situations. Also, responders do use social media, but only within their known community and extended network. This shows that trust first begins with people and not data. Lastly, we demonstrate the barriers used by responding organizations have gone beyond discussions of trustworthiness and data quality to that of more operational issues.     

Reduction of automobile traffic: urgent health promotion policy

During the last few decades, traffic injuries have become one of the leading causes of death and disability in the world. In urban areas, traffic congestion, noise, and emissions from motor vehicles produce subjective disturbances and detectable pathological effects. More than one billion people are exposed to harmful levels of environmental pollution. Because its combustion engine generates carbon dioxide (CO2), the automobile is one of the chief sources of the gases that are causing the greenhouse effect. The latter has already caused a rise in the average ambient temperature, and over the next decades it will predictable cause significant climatic changes whose consequences, though uncertain, are likely to be harmful and possibly catastrophic. Aside from the greenhouse effect, the relentless growth of parking zones, traffic, and the roadway infrastructure in urban and rural areas is currently one of the leading causes of environmental degradation. Urban development, which is nearly always "planned" around traffic instead of people, leads to a significant deterioration in the quality of life, while it also destroys the social fabric. Unlike the private automobile, public transportation, bicycles, and walking help reduce pollution, congestion, and traffic volume, as well as the morbidity and mortality resulting from injuries and ailments related to pollution. Non-automobile transportation also encourages physical activity--with its positive effect on general health--and helps reduce the greenhouse effect. The drop in traffic volume and the increased use of alternate means of transportation are thus an integrated health promotion policy which should become an inherent part of the movement for the promotion of healthy cities and of transportation policies and economic policy in general.     

A consensus model for group decision making problems with linguistic interval fuzzy preference relations

Sometimes, we find decision situations in which it is difficult to express some preferences by means of concrete preference degrees. In this paper, we present a consensus model for group decision making problems in which the experts use linguistic interval fuzzy preference relations to represent their preferences. This model is based on two consensus criteria, a consensus measure and a proximity measure, and on the concept of coincidence among preferences. We compute both consensus criteria in the three representation levels of a preference relation and design an automatic feedback mechanism to guide experts in the consensus reaching process.     

Study of the influence of the pH media dissolution, degree of polymerization, and degree of swelling of the polymers on the mechanism of release of diltiazem from matrices based on mixtures of chitosan/alginate

The dissolution profiles of formulations based on mixtures of chitosan/alginate depend on the pH. It is possible to distinguish two processes: (a) a fast kinetic drug release up to 180 min, where the pH value changes from 1.17 to 2.21 and the drug released is controlled by the degree of polymerization and the quantity of chitosan in the formulation; (b) a low kinetic drug release between 210 and 480 min, where the pH value changes from 5.52 to 8.72 and the drug release from the matrix is controlled by the interpolymeric complex. In all formulations the order of release, according to Peppas's model in the range of fast kinetic drug release, was between 0.5 and 1.0. The mechanism of release was non-fickian diffusion, which corresponds to a coupling mechanism of diffusion and relaxation of the polymer.     

Removal of Inorganic Mercury from Polluted Water Using Structured Nanoparticles

This paper presents a process for the removal of inorganic mercury from aqueous solutions using alumina nanoparticles, which were prepared by the sol-gel method. Different amounts of mercury were added to the particles until a critical concentration was achieved, thus inducing the alumina sol flocculation. Particle growth was monitored during the process using dynamic light scattering. The amount of metal ion adsorbed on the surface of the alumina sols was determined by atomic absorption spectroscopy. Initial mercury concentrations ranging between 50 and 100 ppm decreased to below 1 ppb in a short time.     

Structural transitions in neutral and charged proteins in vacuo

In vacuo proteins provide a simple laboratory to explore the roles of sequence, temperature, charge state, and initial configuration in protein folding. Moreover, by the very absence of solvent, the study of anhydrous proteins in vacuo will also help us to understand specific environmental effects. From the experimental viewpoint, these systems are now beginning to be characterized at low resolution. Molecular dynamics (MD) simulations, in combination with tools for protein shape analysis, can complement experiments and provide further insights on the folding-unfolding transitions of these proteins. We review some aspects of this issue by using the results from a detailed MD study of hen egg-white lysozyme. For lysozyme ions, unfolding can be triggered by Coulombic repulsion. In neutral lysozyme, unfolding can be induced by centrifugal forces and also by weakening the monomer-monomer interaction. In both cases, the resulting unfolded transients can be used as initial configurations for relaxation dynamics. All trajectories are analyzed in terms of global molecular shape features of the backbone, including its anisometry and chain entanglement complexity. This strategy allows us to quantify separately the degree of polymer collapse and the evolution of large-scale folding features. Using these last two notions, we discuss some basic questions regarding the nature of the accessible paths associated with unfolding from, and refolding into, compact conformers.     

Mémoire et émotion dans le trouble de stress post-traumatique (TSPT).

In Posttraumatic Stress Disorder (PTSD), the hypermnesis linked to the trauma produces various emotional disturbances that result in a state of increased hypersensitivity towards environmental stimuli. Accordingly, memory and emotional functions play a predominant role in the PTSD symptomatology. Through a distinctive approach to the cognitive psychopathology research, the goal of this review is to define the nature of the links between the memory and emotional processes in PTSD. The research conducted in this area, whether on explicit or implicit memory, reveals a memory bias in information specific to the trauma. In determining the workings of the cognitive mechanisms responsible for this traumatic information bias, we hope that this will provide a basis for progress to be made in the understanding of the cognitive mechanisms responsible for the repetitive mnemic symptoms of PTSD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)