Factors influencing human exposure assessment of organophosphorus flame retardants (OPFRS) via indoor dust ingestion

Concentrations of selected organophosphate flame retardants (PFRs) were determined in samples of living room dust from differents countries with international differences in absolute concentrations and relative abundance of different PFRs. Other substantial international differences were observed that are likely attributable to variations in flame retardant legislation and use between different countries. Within-room, within-home, and between home temporal and spatial variation in concentrations of PFRs in floor dust and elevated surface dust was studied in 3 homes from Birmingham, UK. Of particular note are the seasonal variations in PFR concentrations where by higher concentrations were observed in spring and summer; and that between-home spatial variation was largely attributable to differences in flooring composition. Moreover, higher concentrations were generally found in elevated surface rather than floor dust. Concentrations of PFRs were determined in indoor air from houses and offices in Birmingham, UK. Finally, controlled chamber experiments were conducted to examine the magnitude and rate of PFR transfer from a treated fabric to dust via direct fabric-dust contact. A key finding was that source-to-dust transfer via direct contact occurs and over the time period of our experiments was proportional to the duration of contact; with the majority of PFRs, transfer from fabric to dust via direct contact occurs within the first 4 days of contact

Análisis de un circuito hidráulico de circulación natural para el enfriamiento de un fluido

En este trabajo de tesis se presenta un estudio param´etrico del dise˜no de un circuito hidr´aulico de circulaci´on natural mediante un an´alisis num´erico del transporte de calor por convecci´on natural, en el que se evalu´o el efecto que tienen diferentes factores geom´etricos y adimensionales, sobre los fen´omenos de transporte en el circuito. Se consider´o un circuito hidr´aulico formado por dos serpentines interconectados entre s´ı, de di´ametro y volumen constante, lleno de un fluido newtoniano, espec´ıficamente agua con propiedades constantes, excepto la densidad, cuya variaci´on es dependiente de la temperatura y fue calculada mediante una ecuaci´on polinomia

The Sonozotz project: Assembling an echolocation call library for bats in a megadiverse country

Bat acoustic libraries are important tools that assemble echolocation calls to allow the comparison and discrimination to confirm species identifications. The Sonozotz project represents the first nation-wide library of bat echolocation calls for a megadiverse country. It was assembled following a standardized recording protocol that aimed to cover different recording habitats, recording techniques, and call variation inherent to individuals. The Sonozotz project included 69 species of echolocating bats, a high species richness that represents 50% of bat species found in the country. We include recommendations on how the database can be used and how the sampling methods can be potentially replicated in countries with similar environmental and geographic conditions. To our knowledge, this represents the most exhaustive effort to date to document and compile the diversity of bat echolocation calls for a megadiverse country. This database will be useful to address a range of ecological questions including the effects of anthropogenic activities on bat communities through the analysis of bat sound.</p