Development of highly active coated monolith SCR catalyst with strong abrasion resistance for low-temperature application

Monolith SCR catalysts coated with V₂O₅-WO₃/TiO₂ were prepared by varying binder and coating thickness. Comparing with a monolith extruded with 100% V₂O₅-WO₃/TiO₂ powder, a coated monolith with a catalyst-coating layer of 260 μm in thickness exhibited the similar initial NO_x reduction activity at 250°C. After 4 h abrasion (attrition) in an air stream containing 300 g·m⁻³ fine sands (50–100 μm) at a superficial gas velocity of 10 m·s⁻¹, the catalyst still has the activity as a 100% molded monolith does in a 24-h activity test and it retains about 92% of its initial activity at 250°C. Estimation of the equivalent durable hours at a fly ash concentration of 1.0 g·m⁻³ in flue gas and a gas velocity of 5 m·s⁻¹ demonstrated that this coated monolith catalyst is capable of resisting abrasion for 13 months without losing more than 8% of its initial activity. The result suggests the great potential of the coated monolith for application to de-NO_x of flue gases with low fly ash concentrations from, such as glass and ceramics manufacturing processes.     

High seagrass diversity and canopy-height increase associated fish diversity and abundance

Seagrass species function as typical foundation species that unifies most ecosystem processes. This ecosystem role depends largely on the morphological characteristics and structural complexity of seagrass beds, including their ecological importance for fish species. This study examined relationships between seagrass bed characteristics and associated fish communities in mixed seagrass beds. Correspondence analysis (CA) and canonical correlation analysis (CCoA) were performed to estimate relationships for individual seagrass bed characteristics. The CCoA results revealed that species richness and three-dimensional structure of seagrass had great effect on the biomass and richness of the associated fish community. The CA results revealed that the relative importance of seagrass bed characteristics differed among fish functional groups including fishes appearing on the surface of, inside, and on the bottom of seagrass beds. The fishes found on the surface of the beds preferred beds with low seagrass biomass and high three-dimensional structure, those inside the beds preferred beds with high seagrass biomass and high three-dimensional structure, and those on the bottom of the beds preferred locations with low seagrass biomass and low three-dimensional structure. The results of this study provide compelling evidence that seagrass beds with high species diversity and high three-dimensional structure, but intermediate biomass, may provide the great benefit to the associated fish community. Such niche complementarity among fishes may be a process facilitated by seagrass diversity for secondary production as an ecosystem functioning.     

Effects of deltamethrin on serum calcium and corpuscles of Stannius of freshwater catfish,Heteropneustes fossilis

Adult male deer mice were exposed every other day for a period of 11 days to either 7,12-dimethylbenzanthracene (DMBA; CAS# 57-97-6) or benzo[b]fluoranthene (BbF; CAS# 205-99-2) (0, 0.3, 1, 3, 10, or 30?mg?kg^?1). Immune endpoints assessed were lymphocyte proliferation, macrophage pinocytosis, and the antibody plaque-forming cell (PFC) response. Cytochrome P450 (CYP450) activity was assessed using ethoxyresorufin-O-deethylase (EROD) and pentoxyresorufin-O-deethylase (PROD). Macrophage pinocytosis was not altered by either compound. Both T- and B-cell proliferations were significantly increased by DMBA at 0.3 or 1?mg?kg^?1 and by BbF at 10 or 30?mg?kg^?1, but decreased by DMBA at 30?mg?kg^?1. Sheep red blood cell (SRBC)-specific-IgM production, as measured by the PFC response, was the most striking adverse immune effect observed and was significantly suppressed compared to control at all treatment concentrations for both compounds. EROD activity was markedly induced by DMBA at 30?mg?kg^?1, while BbF produced induction at 1, 10, or 30?mg?kg^?1. No marked effect on PROD activity was noted following DMBA treatment, but BbF-induced PROD activity at 1, 10, or 30?mg?kg^?1. Unexpectedly, four of six mice in the 30?mg DMBA?kg^?1 group did not survive to the end of the experiment, and one animal died in both the 3 and 10?mg?kg^?1 treatments. The calculated LD₅₀ was 20.8?mg DMBA?kg^?1. The PFC response in deer mice was a more sensitive endpoint than CYP450 activity, suggesting that utilization of CYP450 endpoints in risk assessment without assessment of immune function, specifically antibody production, might possibly underestimate the risk to wild rodents environmentally exposed to polycyclic aromatic hydrocarbons.     

Salivary cortisol and cortisone levels,and breast milk dioxin concentrations in Vietnamese primiparas

There is a great deal of concern regarding the adverse effects of polychlorinated dibenzodioxins (PCDD) and polychlorinated dibenzofurans (PCDF) present in Agent Orange and other herbicides on Vietnam's population and ecosystems. The purpose of this study was to determine the effect of dioxin exposure on adrenal steroids in saliva, and dioxin levels in breast milk, of primiparas in an Agent Orange/dioxin hot-spot and a non-exposed area in Vietnam on the basis of epidemiological research. The subjects were 35 lactating women who had recently given birth to their first or second child. A further sub-study involved eight primiparas from each area. All subjects were aged between 20 and 30 years with infants aged between 4 and 16 weeks. The mean concentration of PCDD, PCDF, and PCDD?+?PCDF toxic equivalents (TEQ) in breast milk in the hot-spot area was significantly higher than in the non-exposed area. Cortisol and cortisone levels in the saliva of primiparas in the hot-spot area were also significantly higher than those in the non-exposed area. There was a significant negative correlation between cortisol and the cortisol/cortisone ratio and PCDD?+?PCDF and PCDF TEQ levels in the hot-spot area. Furthermore, the correlation between cortisol and cortisone and the PCDD + PCDF, PCDD, and PCDF TEQ in the combination of hot spot + non-exposed area was significant according to the curve (bell style). Our results suggest that Agent Orange/dioxin exposure still exerts a major influence on the salivary hormones of the Vietnamese population.     

Influence of a botanical pesticide,azadirachtin, on ultimobranchial gland of the freshwater catfish Heteropneustes fossilis

Freshwater catfish, Heteropneustes fossilis, were subjected to 42 mg L^?1 of azadirachtin for short-term exposure (96 h) and to 10.5 mg L^?1 for long-term exposure (28 days). Six fishes were sacrificed on each time interval from control and experimental groups after 24, 48, 72, and 96 h in the short-term exposure and after 7, 14, 21, and 28 days in the long-term experiment. The calcium regulating endocrine gland, viz. the ultimobranchial gland, was fixed for histological studies. Up to 72 h of azadirachtin treatment, there was no histological alteration in the UBG (ultimobranchial gland) of H. fossilis. After 96 h exposure, the ultimobranchial cells stain feebly and the nuclear volume of these cells were slightly decreased. No histological alterations have been observed in the UBG cells up to 14 days following azadirachtin exposure. After 21 days, the cytoplasm of ultimobranchial cells was feebly stained and the nuclear volume exhibits a decrease. The nuclear volume of these cells was further decreased and the gland shows vacuolization and degeneration at certain places after 28 days azadirachtin treatment. Hence, it can be concluded that azadirachtin severely affects the physiology of calcium homeostasis in H. fossilis. Therefore, the botanical pesticides should be used carefully near aquatic reservoirs.     

Honeybee foragers adjust crop contents before leaving the hive

Upon leaving the hive, foragers carry a small amount of honey, which they subsequently consume to generate energy for flight. We investigated the relationship between waggle-phase duration and crop volume in foragers (both dancers and dance followers) leaving the hive. Our findings indicate that these variables were positively correlated in the two types of bee, suggesting that they were able to adjust the amount of food that they carry depending on the distance to a food source. We also found that dance followers left the hive with a larger amount of honey than dancers. We suggest two possible explanations: (1) dance followers have less information about the location of the food source than dancers, who have a better knowledge of the surrounding area; or (2) honeybees lack a precise calibration method for estimating energy needs from waggle-run duration. The effect of foraging experience was confirmed: bees decreased their honey load at departure with repeated trips to a sugar-syrup feeder. Honeybees showed a different pattern of change when the feeder provided soybean flour as a pollen substitute, possibly because honeybees use honey not only as an energy source but also as “glue” to form “balls” of pollen on their hind legs. Based on our observations that followers of sugar-syrup foragers carry a different amount of honey in their crop than followers of soybean-followers, we suggest that waggle dancers also convey information concerning food type.