33 research outputs found

    Air pollution studies in Metromanila and catalysis technology towards clean air Philippines

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    Considerable air quality and emission data gathered in Metropolitan Manila (MM) led to the development of automobile exhaust treatment catalysts as well as their continued improvement. Findings of a 5-year (1993-1998) collaborative work on the development of base metal oxide catalysts for automobile exhaust are summarized here. One study in 1991 reveals an average 16% increase in the number of motor vehicles in MM where 16% are new and the rest are old ones. Another study in 1992 shows the CO and hydrocarbon emission levels from different types of motor vehicles in MM as a function of the age of the vehicle, type of fuel, and the operating condition. Reports of the Department of Environment and Natural Resources (DENR) and other related studies also provided data showing the quality of air in MM. Currently, there are several requirements to further improve the catalyst performance towards the reduction of NOx and to develop catalyst-sorbent for simultaneous NOx-SOx removal. This is so because of the present condition of rain acidification that is found in certain places in MM. These air quality and emission data are needed not only to establish practical emission standards for motor vehicles and the stationary industries and power plants but also in the development of technologies for air pollution control and other clean technologies for cleaner air in the country

    Behavioral response of delphinids to sonar - supporting acoustic data

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    Oceanic delphinids around naval operations are regularly exposed to intense military sonar broadcast within the frequency range of their hearing. However, empirically measuring the impact of sonar on the behavior of highly social, free-ranging dolphins is challenging. Additionally, baseline variability or the frequency of vocal state-switching among social oceanic dolphins during undisturbed conditions is lacking, making it difficult to attribute changes in vocal behavior to anthropogenic disturbance. Using a network of drifting acoustic buoys in controlled exposure experiments, we investigated the effects of mid-frequency (3-4 kHz) active sonar (MFAS) on whistle production in short-beaked (Delphinus delphis delphis) and long-beaked common dolphins (Delphinus delphis bairdii) in southern California. Given the complexity of acoustic behavior exhibited by these group-living animals, we conducted our response analysis over varying temporal windows (10 min – 5 s) to describe both longer-term and instantaneous changes in sound production. We found that common dolphins exhibited acute and pronounced changes in whistle rate in the 5 s following exposure to simulated Navy MFAS. This response was sustained throughout sequential MFAS exposures within experiments simulating operational conditions, suggesting that dolphins may not habituate to this disturbance. These results indicate that common dolphins exhibit brief yet clearly detectable acoustic responses to MFAS. They also highlight how variable temporal analysis windows – tuned to key aspects of baseline vocal behavior as well as experimental parameters related to MFAS exposure – enable the detection of behavioral responses. We suggest future work with oceanic delphinids explore baseline vocal rates a-priori and use information on the rate of change in vocal behavior to inform the analysis time window over which behavioral responses are measured

    Fundamental challenges and engineering opportunities in flue gas desulfurization wastewater treatment at coal fired power plants

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