Evaluation of noise environments during daily activities of university students

Noise conditions specifically in areas inside university facilities and its impact on the quality of life of university students are topics that have received little attention. This paper presents a study of the noise conditions in which university students of various institutions in Madrid, Spain, carry out their daily studies. A representative number of measurements was carried out using noise dosemeters and dataloggers in order to evaluate the levels of noise, noise dose and exposure to noise during school periods and extracurricular activities. The results were compared with the recommendations given by current environmental noise regulations. This paper was complemented with a survey to get to know how students perceive the exposure to noise in university environments.     

Flammability of heat transfer fluid aerosols produced by electrospray measured by laser diffraction analysis

Accidental release of pressurized high flash point heat transfer fluids can result in fire and explosion hazard scenarios in the process industry. An experimental investigation on ignition of aerosols of a heat transfer fluid is carried out, and characterization of aerosol and its ignition process by non-intrusive laser diffraction technique is reported. Propagation speed of the aerosol combustion flame front as analyzed from the laser diffraction measurement agrees with high-speed visual camera observation. Flammability of the aerosol, which is based on the chances of the global flame appearance in the aerosol, is mainly controlled by aerosol droplet size and the droplet volume concentration.     

Feeding and movement patterns of the sea cucumber Holothuria sanctori

Sea cucumbers are conspicuous organisms inhabiting almost all marine habitats across the globe. Despite their importance as effective consumers of detritus, little is known about their behavior. We studied organic matter (OM) consumption and nocturnal movement patterns of Holothuria sanctori through indoors assays and in situ experiments at shallow bottoms off Gran Canaria Island (Canary Islands, Spain). H. sanctori has a selective feeding toward high OM concentration sediments. Consumption of OM increased with OM availability, particularly during formation of the gonads. OM consumption did not differ in situ between two adjacent habitats arranged in mosaics: macroalgal beds and urchin-grazed “barrens.” Larger distances and fastest displacements were covered by H. sanctori during the end than the middle and start of the nighttime. Overall, we did not detect a clear “homing” behavior by H. sanctori, yet some individuals showed a fidelity for refuges when shelter availability was lacking.     

An integrative response by Mytilus chilensis to the toxic dinoflagellate Alexandrium catenella

Physiological responses of Mytilus chilensis exposed to the toxic dinoflagellate Alexandrium catenella were measured over 21 days in the laboratory and were compared with control mussels not exposed to the dinoflagellate. Mussels were collected from culturing ropes at Yaldad Bay, southern Chile (43o08′S 73o44′W), in August 2004 and acclimated to laboratory conditions for one week prior to the experiment. After 8 days, the paralytic shellfish poisoning (PSP) toxins (i.e. saxitoxin) in the tissues of exposed mussels exceeded safe levels for human consumption. Clearance rates, ingestion of organic matter, and absorption efficiency of exposed mussels were significantly lower than those of controls on day 0, but this was followed by an increase on day 3. The exposed mussels also increased their excretion rate over time, and this increase was significantly correlated with the accumulation of PSP toxins in their tissues. Oxygen consumption was not affected by the PSP toxins. The scope for growth (SFG) on day 0 was negative in exposed mussels, but it increased during the experiment. Although feeding activity and absorption efficiency were adversely affected during the first few days of exposure to PSP toxins from A. catenella in the laboratory, the M. chilensis cultured in Yaldad Bay may have evolved mechanisms that allow them to exploit the toxic dinoflagellate as a food source.     

Methodology for quantification of waste generated in Spanish railway construction works

In the last years, the European Union (EU) has been focused on the reduction of construction and demolition (C&D) waste. Specifically, in 2006, Spain generated roughly 47million tons of C&D waste, of which only 13.6% was recycled. This situation has lead to the drawing up of many regulations on C&D waste during the past years forcing EU countries to include new measures for waste prevention and recycling. Among these measures, the mandatory obligation to quantify the C&D waste expected to be originated during a construction project is mandated. However, limited data is available on civil engineering projects. Therefore, the aim of this research study is to improve C&D waste management in railway projects, by developing a model for C&D waste quantification. For this purpose, we develop two equations which estimate in advance the amount, both in weight and volume, of the C&D waste likely to be generated in railway construction projects, including the category of C&D waste generated for the entire project.     

Assessment of groundwater contamination caused by uncontrolled dumping in old gravel quarries in the Besòs aquifers (Barcelona,Spain)

The contamination of groundwater in the aquifer of the La Llagosta basin (Besòs river basin) due to waste disposal in quarries formerly used for the extraction of dry raw materials has led to the cessation of groundwater extraction for public water supply. The mobilization of pollutants was largely caused by fluctuations in piezometric levels, which led to the washing of buried waste. The hydrogeochemical processes associated with uncontrolled waste disposal in these landfilled areas of the La Llagosta basin aquifer were studied along a flow path that crosses the contaminated area. The PHREEQC code was used to establish the reactions associated with the different mineral phases through inverse modeling. This transport code, ionic exchange phenomena, surface reactions and balance (mineral phase) reactions were used to simulate the dilution phenomenon associated with the pollution after the potential removal of the sources of contamination. One-dimensional advective–dispersive modeling indicates a substantial reduction in Ca, Mg, Na and SO₄²⁻ within one year and stabilization within four years.     

Air-water PCB fluxes from southwestern Lake Michigan revisited

From simultaneous air and water polychlorinated biphenyl (PCB) measurements collected in September 2010, we re-evaluated the direction and magnitude of net air-water exchange of PCBs in southwest Lake Michigan and compared them with estimations made using similar approaches 15 years prior. Air and water samples were collected during a research expedition on Lake Michigan at 5 km off the coast of Chicago, with prevailing winds from the southwest of our location. Gas-phase ΣPCB concentrations ranged from 190 to 1100 pg m^?3 with a median of 770 pg m^?3, which is similar to the concentrations measured in the City of Chicago at the same time and similar to concentrations measured in this part of the lake over the last 20 years. Water dissolved-phase ΣPCB concentrations ranged from 150 to 170 pg L^?1 with a median of 160 pg L^?1, which is one-tenth of that measured in the 1990s. ?PCB net fluxes showed a slightly absorptive behavior, with a median of (?) 21 ng m^?2 day^?1 and an interquartile range of (?) 47 to (+) 5 ng m^?2 day^?1, where (?) and (+) fluxes indicate absorption and volatilization, respectively. Airborne PCB concentrations were higher when the winds were coming from Chicago and drive the deposition. Our fluxes are not significantly different from estimations from 1994 and 1995 and suggest that absorption of PCBs into the waters is slightly more prevalent than 15 years ago. It was confirmed that Chicago remains an important atmospheric source of PCBs to Lake Michigan.

     

Effects of diet on fatty acid composition of body zones in larvae of the sea bass Dicentrarchus labrax: a chemometric study

Larvae of the sea bass Dicentrachus labrax were fed four Artemia sp. diets for 28 d. Three were nauplii enriched with emulsions of polyunsaturated fatty acids, and the fourth nauplii enriched with baker's yeast. At the end of the experimental period, the fatty acids of the bodies, heads and eyes of the larvae were analysed. A multivariate statistical method (discriminant analysis, DA) applied to the data revealed anatomical as well as dietary fatty acid pattern-discrimination. We propose here the use of discriminant analysis as a pattern-recognition method that will help to integrate the fatty acid information obtained in nutritional studies.     

Persistence of the mixture of chlorfenvinphos and cypermethrin (Survan) in citrus fruits

The Survan (a mixture of the insecticides chlorfenvinphos and cypermethrin) persistence in lemon citrus fruits, verna variety, is studied. In all the cases, residues of both compounds have been detected in the juices of the fruits treated. When the mixture of the insecticides is used at a concentration of 0.20%, the levels of chlorfenvinphos after 14 days is not higher than 0.14 ppm; however, when it is used at a 0.15% concentration, this value is overpassed in all the samples. The residues of the cypermethrin component are not higher than 0.35 ppm throughout the whole experiment.     

Non-immunological hydrops fetalis and intrapericardial teratoma: Case report and review

A large intrapericardial teratoma was found at necropsy in a 38−week stillborn fetus, in which prenatal diagnosis of hydrops fetalis and an ehogenic cardiac mass had been made. Clinical and pathological data are reported. In utero intrapericardial teratomata lead to different outcomes depending on whether fetal hydrops is associated. When generalized fetal hydrops is not present, the outcome is good, even in cases with large pericardial effusions. When generalized fetal hydrops occurs, it often results in a poor outcome. In our literature review, we have found eight perinatal deaths in nine similar cases reported.