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ABSTRACT: Waste waters from various operations at the Miami International Airport are characterized. Servicing, maintenance, overhauling, and washing of aircraft seem to be the most significant waste water producing operations. Pollutional constitutents commonly found in the airport wastes include acids, alkalis, detergents, oil, grease, and oxygen demanding substances. Phenols are of concern when stripping and repainting operations occur. Although most airport wastes may be treatable, a great reduction in influent load can be achieved by proper housekeeping methods.  相似文献   
313.
Alginates are naturally occurring components of organic matter in natural soil whose effects on nanoparticle (NP) toxicity to plants is not well understood. In the present study, corn plants were grown for one month in soil spiked with 400 mg/kg CeO2 NPs with various alginate concentrations. After one month of growth in the NPs impacted soil, plants were harvested and analyzed for Ce and mineral element concentrations. Chlorophyll concentration and heat shock protein 70, used as biomarkers for oxidative stress, were also evaluated. Results showed that, compared to CeO2 NPs treatment, alginate at 10, 50, and 100 mg/kg increased Ce concentration in roots by approximately 46%, 38%, and 29% and by 115%, 45%, and 56% in shoots, respectively. CeO 2 NPs without alginate increased Mn accumulation in roots by 34% compared to control. CeO2 NPs with low and medium alginate increased Mn by ca. 92% respect to NPs without alginate and by ca. 155% respect to control. CeO2 NPs without/with alginate significantly increased accumulation of Fe and Al in roots. In addition, alginate at 50 mg/kg increased Zn accumulation in roots by 52% compared to control. In shoots, K increased at all NP treatments but the accumulation of other elements was not affected. Alginate enlarged the impact of CeO2 NPs to corn plants by reducing chlorophyll a content and triggering overexpression of heat shock protein 70.  相似文献   
314.
The rising prices of crude oil in the world market and the continuing global trend to mainstream renewable energy use have prompted the Philippines to consider alternative fuels. Since 2006 when a new law was implemented requiring a 10 % blend to unleaded gasoline, the use of ethanol has increased significantly. Sugarcane (Saccharum spp.), cassava (Manihot esculenta ) and sweet potato (Ipomoea batatas) have been the major feedstock in ethanol production. This analysis focused on the impacts of E10 (10 % ethanol content) on the retail price of gasoline and how this might affect gasoline prices. Recognizing the direct dependence of the price of E10 on gasoline prices, the analysis focused on analyzing the price of ethanol. The hypothesis is that since ethanol is what makes E10 cheaper than gas given the lower cost of its production i.e., domestically grown raw materials, then cheaper ethanol should depress the price of E10 and therefore gas, ceteris paribus. The price of E10 is endogenous since it is a function of the price of gasoline, being a major input to its production, 90 % in fact. Using fixed-effects, 2007–2009 provincial panel data, from second stage least squares econometric estimation, the impact of ethanol use on retail regular gasoline prices is quantified. The partial effect analysis indicates that a 1-peso (rate: 1USD - PhP 41.96) increase in the price of feedstock prices as inputs to the production of E10 increases the price of gasoline by 37 centavos per liter. The analysis shows the positive relationship between the prices of E10 and gasoline.  相似文献   
315.
A methodology for identifying volatile organic compounds (VOC) and determining air quality of indoor air has been developed. The air samples are collected using pump samplers by the inhabitants when they perceive odorous and/or discomfort episodes. Glass multi-sorbent tubes are connected to the pump samplers for the retention of VOC. The analysis is performed by automatic thermal desorption (ATD) coupled with gas chromatography-mass spectrometry (GC/MS). This methodology can be applied in cases of sick building syndrome (SBS) evaluation, in which building occupants experience a series of varied symptoms that appear to be linked to time spent in the building. Chemical pollutants concentrations (e.g., VOC) have been described to contribute to SBS. To exemplify the methodology, a qualitative determination and an evaluation of VOC present were performed in a dwelling where the occupants experienced the SBS symptoms. Higher total VOC (TVOC) value was detected in episodes in indoor air (1.33 ( 1.53 mg/m3) compared to outdoor air (0.71 ( 0.46 mg/m3). The concentrations of individual VOCs, such as ethanol, acetone, isopropanol, 1-butanol, acetic acid, acetonitrile and 1-metoxy-2-propanol, were also higher than the expected for a standard dwelling. The external source of VOC was found to be a not declared activity of storage and manipulation of solvents located at the bottom of a contiguous building.  相似文献   
316.
In the Brazilian Amazon, private land accounts for the majority of remaining native vegetation. Understanding how land‐use change affects the composition and distribution of biodiversity in farmlands is critical for improving conservation strategies in the face of rapid agricultural expansion. Working across an area exceeding 3 million ha in the southwestern state of Rondônia, we assessed how the extent and configuration of remnant forest in replicate 10,000‐ha landscapes has affected the occurrence of a suite of Amazonian mammals and birds. In each of 31 landscapes, we used field sampling and semistructured interviews with landowners to determine the presence of 28 large and medium sized mammals and birds, as well as a further 7 understory birds. We then combined results of field surveys and interviews with a probabilistic model of deforestation. We found strong evidence for a threshold response of sampled biodiversity to landscape level forest cover; landscapes with <30–40% forest cover hosted markedly fewer species. Results from field surveys and interviews yielded similar thresholds. These results imply that in partially deforested landscapes many species are susceptible to extirpation following relatively small additional reductions in forest area. In the model of deforestation by 2030 the number of 10,000‐ha landscapes under a conservative threshold of 43% forest cover almost doubled, such that only 22% of landscapes would likely to be able to sustain at least 75% of the 35 focal species we sampled. Brazilian law requires rural property owners in the Amazon to retain 80% forest cover, although this is rarely achieved. Prioritizing efforts to ensure that entire landscapes, rather than individual farms, retain at least 50% forest cover may help safeguard native biodiversity in private forest reserves in the Amazon. Umbrales de Pérdida de Especies en los Paisajes Fronterizos de Deforestación en el Amazonas Ochoa‐Quintero  相似文献   
317.
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