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101.
James W. Mjelde Richard M. Adams Bruce L. Dixon Philip Garcia 《Journal of the Air & Waste Management Association (1995)》2013,63(4):360-364
The effects of ozone on the profitability of Illinois cash grain farms is investigated by utilizing a profit function framework. This approach uses individual farms as the observational unit so the data are generated under field conditions. Hence, experimental plot data are not used although results from past biological experiments are utilized to frame initial hypotheses and for evaluation of the estimated model. This study demonstrates the benefits of combining economic data and biological science results to estimate the economic reactions of producers in terms of input and output (production) response to an ambient environmental characteristic. A time series of cross sectional data on cash grain farms in Illinois is used to estimate two profit functions. Ozone data are measured on a growing season basis by county. The estimated model shows ozone has a negative effect on profits. Increases in ozone levels tend to depress output levels and lessen the demand for variable inputs. Additionally, a production function is derived from one of the profit functions. The impact of ozone is found to be in general agreement with dose-response data obtained in Illinois by plant scientists. 相似文献
102.
Xiaoli Chen Nathan Emery Elizabeth S. Garcia Erin J. Hanan Heather E. Hodges Tyronne Martin Matthew A. Meyers Lindsey E. Peavey Hui Peng Jaime Sainz Santamaria Kellie A. Uyeda Sarah E. Anderson Christina Tague 《Environmental management》2013,52(6):1415-1426
Environmental regulations frequently mandate the use of “best available” science, but ensuring that it is used in decisions around the use and protection of natural resources is often challenging. In the Western US, this relationship between science and management is at the forefront of post-fire land management decisions. Recent fires, post-fire threats (e.g. flooding, erosion), and the role of fire in ecosystem health combine to make post-fire management highly visible and often controversial. This paper uses post-fire management to present a framework for understanding why disconnects between science and management decisions may occur. We argue that attributes of agencies, such as their political or financial incentives, can limit how effectively science is incorporated into decision-making. At the other end of the spectrum, the lack of synthesis or limited data in science can result in disconnects between science-based analysis of post-fire effects and agency policy and decisions. Disconnects also occur because of the interaction between the attributes of agencies and the attributes of science, such as their different spatial and temporal scales of interest. After offering examples of these disconnects in post-fire treatment, the paper concludes with recommendations to reduce disconnects by improving monitoring, increasing synthesis of scientific findings, and directing social-science research toward identifying and deepening understanding of these disconnects. 相似文献
103.
Garcia F Barioni A Arruda-Neto JD Deppman A Milian F Mesa J Rodriguez O 《Environment international》2006,32(5):697-703
Natural levels of uranium in the diet of S?o Paulo City residents were studied, and radionuclide concentrations were measured by the fission track method on samples of typical adult food items. This information was used to evaluate the daily intake of uranium in individuals living in S?o Paulo City which is, according to our findings, around 0.97 microg U/day. Using the ICRP Uranium-model, we estimated the uranium accumulation and committed doses in some tissues and organs, as function of time. We compared the output of the ICRP uranium biokinetic model, tailored for the conditions prevailing in S?o Paulo, with experimental data from other localities. Such comparison was possible by means of a simple method we developed, which allows normalization among experimental results from different regions where distinct values of chronic daily intake are observed. 相似文献
104.
105.
The recycling of rubber from old tyres by batch hydrogenation has been performed using tubing bomb reactors. Important process variables like temperature, reaction time, initial hydrogen pressure and nature of gas used have been studied. In all the runs the maximum total conversion was achieved. Conversion products are comprised of oils and gases, being the asphaltene yield lower than 1% in all conditions tested. The most valuable conversion products, oils, have been systematically analysed by TLC-FID1 and the influence of the process variables in oils composition has been assessed. From the obtained results, it can be deduced that the conversion of rubber in oils is a fast thermal process, which is neither affected by initial pressure nor the nature of gas used. But on the other hand, the nature of obtained oils and gases is a function of process variables. 相似文献
106.
Raquel Garcia Rodriguez Loida Garcia Cruz Yeray Novoa Medina Raquel Garcia Delgado Julio Perez Gonzalez Carmen Palma Milla Juan Lopez Siles Margarita Medina Castellano Jose Angel Garcia Hernandez Alfredo Santana Rodriguez 《黑龙江环境通报》2019,39(6):415-419
Solitary median maxillary central incisor (SMMCI) syndrome is a complex disorder consisting of multiple, developmental defects involving midline structures of the head, which includes the cranial bones, the maxilla, and its container dentition (specifically the central incisor tooth germ), together with other midline structures of the body. SMMCI may appear as an isolated trait or in association with other midline developmental anomalies. We describe the case of a patient with SMMCI. He presented with a solitary median maxillary incisor, short stature, corpus callosum anomalies and a microform of holoprosencephaly (HPE), diabetes insipidus, and neurodevelopmental delay. The diagnosis was performed postnatally based on clinical features, radiological imaging, and a comprehensive genetic study. SMMCI can be diagnosed during the prenatal or neonatal periods or during infancy. Evaluation of the superior maxillary bone is important for prenatal diagnosis. Direct evaluation through bidimensional ultrasound or the use of multiplanar ultrasound or tridimensional reconstruction should be performed in cases of brain or face malformations. Early diagnosis can contribute to improved prenatal assessment and postnatal management. 相似文献
107.
H.A. Carreras J.H. Rodriguez C.M. González E.D. Wannaz F. Garcia Ferreyra C.A. Perez M.L. Pignata 《Atmospheric environment (Oxford, England : 1994)》2009,43(18):2944-2949
Samples of the vascular plant Tradescantia pallida and the lichen Usnea amblyoclada were exposed from October 2004 to April 2005 in three sites with different local sources of air pollution in Córdoba city, Argentina. Simultaneous determinations of the ambient levels of total suspended particles were made for each site. Young inflorescenses of T. pallida were collected in November, February and April and the frequency of micronuclei was determined on early tetrads of pollen mother cells. Physiological parameters and the elemental composition of lichen thalli were measured from samples exposed and replaced every month. Significant differences among sampling sites were observed in the frequency of micronuclei measured in T. pallida as well as in many physiological parameters and elements accumulated in lichen thalli. The mass of particulate material as well as the concentration of Ca, Mn, Cu, Zn and Sr was significantly different in different sampling sites, too. These results suggest that in situ biomonitoring using both higher plants and lichens may be of use to characterize air pollution in areas devoid of instrumental monitoring techniques or where it is necessary to explore the distribution of air contaminants at a microscale. 相似文献
108.
Alexandro M.M. Vargas André L. Cazetta Clarice A. Garcia Juliana C.G. Moraes Eurica M. Nogami Ervim Lenzi Willian F. Costa Vitor C. Almeida 《Journal of environmental management》2011
Activated carbons were prepared from flamboyant pods by NaOH activation at three different NaOH:char ratios: 1:1 (AC-1), 2:1 (AC-2), and 3:1 (AC-3). The properties of these carbons, including BET surface area, pore volume, pore size distribution, and pore diameter, were characterized from N2 adsorption isotherms. The activated carbons obtained were essentially microporous and had BET surface area ranging from 303 to 2463 m2 g−1.13C (CP/MAS and MAS) solid-state NMR shows that the lignocellulosic structures were completely transformed into a polycyclic material after activation process, thermogravimetry shows a high thermal resistance, Boehm titration and Fourier-transform infrared spectroscopy allowed characterizing the presence of functional groups on the surface of activated carbons. Scanning electron microscopy images showed a high pore development. The experimental results indicated the potential use of flamboyant pods as a precursor material in the preparation of activated carbon. 相似文献
109.
Tonucci RG Nair PK Nair VD Garcia R Bernardino FS 《Journal of environmental quality》2011,40(3):833-841
Silvopastoral management of fast-growing tree plantations is becoming popular in the Brazilian Cerrado (savanna). To understand the influence of such systems on soil carbon (C) storage, we studied C content in three aggregate size classes in six land-use systems (LUS) on Oxisols in Minas Gerais, Brazil. The systems were a native forest, a treeless pasture, 24- and 4-yr-old eucalyptus ( sp.) plantations, and 15- and 4-yr-old silvopastures of fodder grass plus animals under eucalyptus. From each system, replicated soil samples were collected from four depths (0-10, 10-20, 20-50, and 50-100 cm), fractionated into 2000- to 250-, 250- to 53-, and <53-μm size classes representing macroaggregates, microaggregates, and silt + clay, respectively, and their C contents determined. Macroaggregate was the predominant size fraction under all LUS, especially in the surface soil layers of tree-based systems. In general, C concentrations (g kg soil) in the different aggregate size fractions did not vary within the same depth. The soil organic carbon (SOC) stock (Mg C ha) to 1-m depth was highest under pasture compared with other LUS owing to its higher soil bulk density. The soils under all LUS had higher C stock compared with other reported values for managed tropical ecosystems: down to 1 m, total SOC stock values ranged from 461 Mg ha under pasture to 393 Mg ha under old eucalyptus. Considering the possibility for formation and retention of microaggregates within macroggregates in low management-intensive systems such as silvopasture, the macroaggregate dynamics in the soil seem to be a good indicator of its C storage potential. 相似文献
110.
In this paper a PSIAC-based multi-parameter fuzzy pattern recognition (MPFPR) model is proposed and applied for classifying and ranking the potential soil erosion (PSE). In this approach, standard value matrix is used to define the membership degrees of each catchment to each class and the feature values are used for alternative ranking. The characteristic of PSE for each class is expressed by linguistic variables. The proposed method is straightforward, easy to understand, very practical, and its results may easily be interpreted. To assess the performance of the model, the results of PSIAC MPFPR and original PSIAC method are interpreted and compared with the observed data. It is shown that the proposed approach reflects the fuzzy nature of the soil erosion more efficiently and is quite robust for application in real world cases. 相似文献