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11.
The Coastal Vulnerability and Exposure Degree (CVED) of the Gran Canaria Island and the coastal risk of Playa de Las Canteras (Las Palmas de G.C.) have been assessed by means of a GIS analysis. The evaluation of coastal vulnerability (H) has been performed by using two different levels of analysis: the first one regarding the entire Island (Coastal Vulnerability Index method - CVI), the second one regarding specifically Las Canteras Beach, selected for its socio-economic importance (Coastal Vulnerability Assessment method - CVA). The application of the CVI method, based on geologic-geomorphologic and meteomarine data easily available, has allowed the regional scale assessment of coastal vulnerability (H) along the Gran Canaria coastline and, therefore, the individuation of more critical coast stretches deserving further analysis. The application of the CVA method, based on more specific morphologic-sedimentary beach features that allow to consider both the beach retreat due to storm surge and the coastal inundation due to run-up on the beach, has provided a large scale detail on the coastal vulnerability of Las Canteras Beach. Socio-economic and damage indexes have been determined for the 15 coastal municipalities included in the study area and, by means of the resulting matrix product, the degree of exposure (Ex) along the Gran Canaria coast has been assessed. Finally, the combination of coastal vulnerability and exposure levels has allowed to obtain the Coastal Vulnerability and Exposure Degree (CVED) for the entire Island and the risk levels that characterize specifically Las Canteras Beach. Major results in terms of CVED highlight prevailing low vulnerability and exposure levels along the western coast, and overall high vulnerability and exposure levels along the eastern coast, from Las Palmas de G.C. to San Bartolomé de Tirajana. The focus made on Playa de Las Canteras has allowed to identify the areas characterized by medium and high risk levels that represent approximately one third (940 m) of the entire beach and are located in its central part. The used two-level analysis approach has proved its efficiency by highlighting the degree of coastal vulnerability along the study coast and, especially, more critical coast stretches (CVI method) such as the Playa de Las Canteras that can be successfully analysed with the CVA approach allowing for a large-scale assessment of risk aspects, essential for a correct definition of priority management strategies. Results obtained with the present study, along with the awareness of the increasing phenomena of coastal erosion and marine flooding arising on the mid-long term due to the effects of global climate change, highlight the need for the competent public administrations of Gran Canaria to develop a strategic approach to coastal management and sustainable development that considers as a whole socio-economic values and natural resources, coastal vulnerability and exposure degree, and risk aspects.  相似文献   
12.
Pine wood, pine bark, oak wood and oak bark were pyrolyzed in an auger reactor. A total of 16 bio-oils or pyrolytic oils were generated at different temperatures and residence times. Two additional pine bio-oils were produced at the National Renewable Energy Laboratory in a fluidized-bed reactor at different temperatures. All these bio-oils were fractionated to obtain lignin-rich fractions which consist mainly of phenols and neutrals. The pyrolytic lignin-rich fractions were obtained by liquid-liquid extraction. Whole bio-oils and their lignin-rich fractions were studied as potential environmentally benign wood preservatives to replace metal-based CCA and copper systems that have raised environmental concerns. Each bio-oil and several lignin-rich fractions were tested for antifungal properties. Soil block tests were conducted using one brown-rot fungus (Gloeophyllum trabeum) and one white-rot fungus (Trametes versicolor). The lignin-rich fractions showed greater fungal inhibition than whole bio-oils for a impregnation solution 10% concentration level. Water repellence tests were also performed to study wood wafer swelling behavior before and after bio-oil and lignin-rich fraction treatments. In this case, bio-oil fractions did not exhibit higher water repellency than whole bio-oils. Comparison of raw bio-oils in soil block tests, with unleached wafers, at 10% and 25% bio-oil impregnation solution concentration levels showed excellent wood preservation properties at the 25% level. The good performance of raw bio-oils at higher loading levels suggests that fractionation to generate lignin-rich fractions is unnecessary. At this more effective 25% loading level in general, the raw bio-oils performed similarly. Prevention of leaching is critically important for both raw bio-oils and their fractions to provide decay resistance. Initial tests of a polymerization chemical to prevent leaching showed some success.  相似文献   
13.
14.
The coastal aquifer of Rome is hosted in the Tiber River Delta depositional sequence, in a densely populated area, which was reclaimed at the end of the 19th century. Moderate salinization processes characterize this aquifer. Hydrogeological and hydrochemical surveys were carried out in October 2012 and February 2013 in the southern sector of the Delta. Hydrogeological surveys updated knowledge of groundwater morphology and a detailed conceptual hydrogeological model of the coastal aquifer was realized. Hydrochemical analyses helped to identify the salinization spatial distribution and to specify the main groundwater types. The most salinized water was not detected close to the coastline, where seawater intrusion processes would be expected, but in the inner areas. Moreover, the salinization processes resulted to be slightly marked. Results so far suggest that the source of salinization may be related more to a combination of land use and historical development of the Tiber River Delta, rather than to seawater.  相似文献   
15.
We aimed to measure concentrations of the commonly used artificial sweetener sucralose, following ingestion of doses reflecting a range of consumption and to compare concentrations in children and adults. Eleven adults consumed 355 mL water containing 0 mg (control), 68, 170, or 250 mg sucralose (equivalent to 1–4 diet sodas). A second group of adults (n = 11) consumed 355 mL Diet Rite Cola? (68 mg sucralose and 41 mg acesulfame-potassium (ace-K)) or 68 mg sucralose and 41 mg ace-K in seltzer. Beverages were provided at separate visits in randomized order, prior to an oral glucose tolerance test. Eleven children consumed 0 or 68 mg sucralose in 240 mL water, in an identical study design. Blood was collected before beverage ingestion and serially for 120 min. Sucralose doses (corrected for weight) resulted in similar plasma concentrations in children and adults. Concentrations were comparable whether sucralose was administered in water, combined with ace-K, or in diet soda. Due to their lower body weight and blood volume, children have markedly higher plasma sucralose concentrations after the consumption of a typical diet soda, emphasizing the need to determine the clinical implications of sucralose use in children.  相似文献   
16.
Natural and contaminated waters of the final reaches of the Chubut River (Patagonia, Argentina) were studied to obtain information about river organic matter and effects of domestic and industrial discharges (fishery effluents and sewages). Fluorescence Excitation–Emission Matrices (EEMs) were obtained from samples only filtered (0.45 μm) and diluted, if necessary, to avoid the inner filter effect. In addition, physicochemical parameters were measured to know the quality of the water and the effluents. Results show that EEMs allow a rapid and simple control of the effluents from fisheries and domestic sewage in Chubut River estuary, necessary to take management decisions.  相似文献   
17.
Low impact development best management practices (LID-BMPs) are considered to be cost-effective measures for mitigating the water quantity and quality impact of urban runoff. Currently, there are many types of LID-BMPs, and each type has its own intrinsic technical and/or economical characteristics and limitations for implementation. The selection of the most appropriate BMP type(s) for a specific installation site is therefore a very important planning step. In the present study, a multi-criteria selection index system (MCIS) for LID-BMP planning was developed. The selection indexes include 12 first-level indices and 26 second-level indices which reflect the specific installation site characteristics pertaining to site suitability, runoff control performance, and economics of implementation. A mechanism for ranking the BMPs was devised. First, each individual second-level index was assigned a numeric value that was based on site characteristics and information on LID-BMPs. The quantified indices were normalized and then integrated to obtain the score for each of the first-level index. The final evaluation scores of each LID-BMP were then calculated based on the scores for the first-level indices. Finally, the appropriate BMP types for a specific installation site were determined according to the rank of the final evaluation scores. In order to facilitate the application of the MCIS BMP ranking system, the computational process has been coded into a software program, BMPSELEC. A case study demonstrating the MCIS methodology, using an LID-BMP implementation planning at a college campus in Foshan, Guangdong Province, is presented.  相似文献   
18.
The presence of the anesthetic lidocaine (LDC), the analgesic tramadol (TRA), the antidepressant venlafaxine (VEN) and the metabolites O-desmethyltramadol (ODT) and O-desmethylvenlafaxine (ODV) was investigated in wastewater treatment plant (WWTP) effluents, in surface waters and in groundwater. The analytes were detected in all effluent samples and in only 64% of the surface water samples. The mean concentrations of the analytes in effluent samples from WWTPs with wastewater from only households and hospitals were 107 (LDC), 757 (TRA), 122 (ODT), 160 (VEN) and 637 ng L(-1) (ODV), while the mean concentrations in effluents from WWTPs treating additionally wastewater from pharmaceutical industries as indirect dischargers were for some pharmaceuticals clearly higher. WWTP effluents were identified as important sources of the analyzed pharmaceuticals and their metabolites in surface waters. The concentrations of the compounds found in surface waters ranged from 相似文献   
19.
2,4-Dichlorophenol (2,4-DCP) is widely distributed in wastewaters discharged from several industries, and it is considered as a priority pollutant due to its high toxicity. In this study, the use of different peroxidase extracts for 2,4-DCP removal from aqueous solutions was investigated. Tobacco hairy roots (HRs), wild-type (WT), and double-transgenic (DT) for tomato basic peroxidases (TPX1 and TPX2) were used to obtain different peroxidase extracts: total peroxidases (TPx), soluble peroxidases (SPx), and peroxidases ionically bound to the cell wall (IBPx). All extracts derived from DT HRs exhibited higher peroxidase activity than those obtained from WT HRs. TPx and IBPx DT extracts showed the highest catalytic efficiency values. The optimal conditions for 2,4-DCP oxidation were pH 6.5, H2O2 0.5 mM, and 200 U mL?1 of enzyme, for all extracts analyzed. Although both TPx extracts were able to oxidize different 2,4-DCP concentrations, the removal efficiency was higher for TPx DT. Polyethylene glycol addition slightly improved 2,4-DCP removal efficiency, and it showed some protective effect on TPx WT after 2,4-DCP oxidation. In addition, using Lactuca sativa test, a reduction of the toxicity of post removal solutions was observed, for both TPx extracts. The results demonstrate that TPx extracts from both tobacco HRs appear to be promising candidate for future applications in removing 2,4-DCP from wastewaters. This is particularly true considering that these peroxidase sources are associated with low costs and are readily available. However, TPx DT has increased peroxidase activity, catalytic efficiency, and higher removal efficiency than TPx WT, probably due to the expression of TPX1 and TPX2 isoenzymes.  相似文献   
20.
The reproductive history of 45 couples at increased risk for neural tube defect (NTD) who came for genetic counselling in 1970 and 1971 were compared with a similar number counselled in 1975 and 1976, when prenatal diagnostic tests were freely offered. They were subsequently interviewed in their homes and had their reproductive history recorded to the end of 1973 and 1978 respectively. Nearly all had a previous child with an NTD and none of the women were pregnant at the time of counselling. The effect of prenatal diagnosis was to speed somewhat the decision about further pregnancies, but the number of couples deciding on no further children and on having further pregnancies were almost identical in the two groups. The average number of pregnancies was 2·8 per family, with only 1·2 surviving children. The pregnancy outcomes are discussed as are the reasons for not attempting further pregnancies in both groups, which included very high risk of recurrence, a surviving spina bifida child, inability to accept the tests or its implications. Ninety per cent of the second group had tests. Their reactions to the tests were favourable but all complained of the waiting time between amniocentesis and obtaining the results. They all would have tests again in any future pregnancy. The reason for women not having prenatal diagnostic tests included inability to accept termination. It is concluded that couples in South Wales decide either to have no more children or to have further pregnancies regardless of tests. but tests speed a decision and enable the women to enjoy the pregnancy after obtaining the results, and that an NTD greatly reduces the number of children per family. A termination for an NTD is much more acceptable to most than an NTD at term. The reasons for this are discussed.  相似文献   
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