Simulation of wind-driven dispersion of fire pollutants in a street canyon using FDS

Air quality in urban areas attracts great attention due to increasing pollutant emissions and their negative effects on human health and environment. Numerous studies, such as those by Mouilleau and Champassith (J Loss Prevent Proc 22(3): 316–323, 2009), Xie et al. (J Hydrodyn 21(1): 108–117, 2009), and Yassin (Environ Sci Pollut Res 20(6): 3975–3988, 2013) focus on the air pollutant dispersion with no buoyancy effect or weak buoyancy effect. A few studies, such as those by Hu et al. (J Hazard Mater 166(1): 394–406, 2009; J Hazard Mater 192(3): 940–948, 2011; J Civ Eng Manag (2013)) focus on the fire-induced dispersion of pollutants with heat buoyancy release rate in the range from 0.5 to 20 MW. However, the air pollution source might very often be concentrated and intensive, as a consequence of the hazardous materials fire. Namely, transportation of fuel through urban areas occurs regularly, because it is often impossible to find alternative supply routes. It is accompanied with the risk of fire accident occurrences. Accident prevention strategies require analysis of the worst scenarios in which fire products jeopardize the exposed population and environment. The aim of this article is to analyze the impact of wind flow on air pollution and human vulnerability to fire products in a street canyon. For simulation of the gasoline tanker truck fire as a result of a multivehicle accident, computational fluid dynamics large eddy simulation method has been used. Numerical results show that the fire products flow vertically upward, without touching the walls of the buildings in the absence of wind. However, when the wind velocity reaches the critical value, the products touch the walls of the buildings on both sides of the street canyon. The concentrations of carbon monoxide and soot decrease, whereas carbon dioxide concentration increases with the rise of height above the street canyon ground level. The longitudinal concentration of the pollutants inside the street increases with the rise of the wind velocity at the roof level of the street canyon.     

A review of virus and protein sorption by ion exchange resins

This paper reviews the use of ion exchange resins for adsorbing proteins and viruses and for purifying viral suspensions. The analysis of resin performance under different conditions provides some information on the fundamental nature of virus/protein-resin interaction.A variety of systems are considered and the influence of factors such as resin type, resin pretreatment, chemical characteristics of the solution and virus type on adsorption are discussed and compared. Analogies are made between virus-host and virus-resin interactions, both of which are specific to the virus-host or virus-resin pair. Consideration is given to the use of proteins as models for virus adsorption. The use of viral parameters such as iso-electric point and the amino acid content of the protein coat for predicting virus adsorption behavior is also discussed. Anion exchange resins were found to be more effective virus sorbents than cation exchange resins. Cation exchange resins were ineffective in low ionic strength media, while anion exchange resins were most effective in low ionic strength media.     

Cephalopod hatchling growth: the effects of initial size and seasonal temperatures

Temperature is known to have a strong influence on cephalopod growth during the early exponential growth phase. Most captive growth studies have used constant temperature regimes and assumed that populations are composed of identically sized individuals at hatching, overlooking the effects of seasonal temperature variation and individual hatchling size heterogeneity. This study investigated the relative roles of initial hatchling size and simulated natural seasonal temperature regimes on the growth of 64 captive Octopus pallidus over a 4-month period. Initial weights were recorded, and daily food consumption and fortnightly growth monitored. Two temperature treatments were applied replicating local seasonal water temperatures: spring/summer (14–18°C) and summer/autumn (18–14°C). Overall octopuses in the spring/summer treatment grew at a rate of 1.42% bwd⁻¹ (% body weight per day) compared to 1.72% bwd⁻¹ in the summer/autumn treatment. Initial size influenced growth rate in the summer/autumn treatment with smaller octopuses (<0.25 g) growing faster at 1.82% bwd⁻¹ compared to larger octopuses at 1.68% bwd⁻¹. This was opposite to individuals in the spring/summer treatment where smaller octopuses grew slower at 1.29% bwd⁻¹ compared to larger octopuses at 1.60% bwd⁻¹. Initial size influenced subsequent growth, however, this was dependent on feeding rate and appears to be secondary to the effects of temperature.     

Reproduction in the deepwater squid<Emphasis Type="Italic"> Moroteuthis ingens</Emphasis>, what does it cost?

The cost of reproduction for the terminal spawning onychoteuthid squid, Moroteuthis ingens, was analysed using measures of condition and tissue biochemistry. Both males and females showed a dramatic drop in the weight of the gonad in stage 6 (spent) individuals. The mantle weight and nidamental gland weight of females also decreased during the maturation process. Males, however, had a marked increase in both the penis and spermatophoric complex weight in spent individuals, while female oviducal gland weight and nidamental gland length also increased in stage 6 individuals. Residual analysis indicated that testis growth was not developing at the expense of mantle growth, although there was a suggestion of cost to the fins. Females showed that the development of the ovary occurred at a cost to both the mantle and fins. Overall body condition also declined with maturity stage for both males and females, with stage 6 individuals of both sexes in poor condition. Very few females had eggs in the oviducts, suggesting that the oviducts are used as ducts instead of storage organs. Proximal analysis revealed a loss of constituents within the mantle during maturation, with an associated increase in water, indicating the remobilization of energy from the mantle to fuel reproduction. This study suggests that the digestive gland is not used as an energy store in this species.Communicated by M.S. Johnson, Crawley