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151.
An important question with respect to the Macondo blowout is whether the accident is a symptom of systemic safety problems in the deepwater drilling industry. An answer to such a question is hard to obtain unless the risk level of the oil and gas (O&G) industry is monitored and evaluated over time. This article presents information and indicators from the Risk Level Project (RNNP) in the Norwegian O&G industry related to safety climate, barriers and undesired incidents, and discusses the relevance for deepwater drilling. The main focus of the major hazard indicators in RNNP is on production installations, whereas only a limited number of incident indicators and barrier indicators are related to mobile drilling units. The number of kicks is an important indicator for the whole drilling industry, because it is an incident with the potential to cause a blowout. Currently, the development and monitoring of safety indicators in the O&G industry seems to be limited to a short list of “accepted” indicators, but there is a need for more extensive monitoring and understanding. This article suggests areas of extensions of the indicators in RNNP for drilling based on experience from the Macondo blowout. The areas are related to schedule and cost, well planning, operational aspects, well incidents, operators’ well response, operational aspects and status of safety critical equipment. Indicators are suggested for some of the areas. For other areas, more research is needed to identify the indicators and their relevance and validity. 相似文献
152.
Runoff coefficients are usually considered in isolation for each drainage area with resulting large uncertainties in the areas
and coefficients. Accurate areas and coefficients are obtained here by optimizing runoff coefficients for characteristic Geographic
Information Systems (GIS) subareas within each drainage area so that the resulting runoff coefficients of each drainage area
are consistent with those obtained from runoff and rainfall volumes. Lack of fit can indicate that the ArcGIS information
is inaccurate or more likely, that the drainage area needs adjustment. Results for 18 drainage areas in Milwaukee, WI for
2000–2004 indicate runoff coefficients ranging from 0.123 for a mostly residential area to 0.679 for a freeway-related land,
with a standard error of 0.047. Optimized runoff coefficients are necessary input parameters for monitoring, and for the analysis
and design of in situ stormwater unit operations and processes for the control of both urban runoff quantity and quality. 相似文献
153.
Intraspecific variation in the strength of inducible plant defenses plays a central role in the interactions between plants and herbivores. Studies of this variation are typically conducted in the greenhouse or laboratory rather than the field. We simultaneously manipulated densities of local consumers in the field within Maine and South Carolina populations of the smooth cordgrass Spartina alterniflora. South Carolina, but not Maine, plants induced resistance when grazed by local consumers. South Carolina populations of Littoraria snails and planthoppers colonized control more than previously grazed South Carolina plants, and Littoraria snails consumed more control than previously grazed plants. The inducible feeding deterrents in South Carolina plants appear to be water soluble, but not phenolic based. In contrast, grazed and control plants from Maine populations did not differ in attractiveness or palatability to Maine consumers. Thus, inducible plant responses by South Carolina plants had a strong effect on the South Carolina consumer community, but no analogous effect occurred in Maine. Field experiments are a powerful approach to detecting the strength of inducible plant resistance and its impacts on local consumers, which in this case were shown to vary with location. 相似文献
154.
Martin J. Steinbauer Fredrik Östrand Tom E. Bellas Anna Nilson Fredrik Andersson Erik Hedenström Michael J. Lacey P. Florian Schiestl 《Chemoecology》2004,14(3-4):217-223
Summary. The autumn gum moth, Mnesampela privata
(Guenée) (Lepidoptera: Geometridae), is native to Australia
and can be a pest of plantation eucalypts. Field-collected
and laboratory-reared female autumn gum moths were
dissected to remove glands likely to contain components of
the sex pheromone. Using gas chromatography (GC) and
combined gas chromatography–mass spectrometry (GC-MS),
three compounds were identified from female extracts,
namely (3Z,6
Z,9
Z)-3,6,9-nonadecatriene, 1-hexadecanol
and 1-octadecanol (confirmed by comparison with synthetic
samples). Nonadecatriene elicited an antennal response in
male autumn gum moth during gas chromatographic
analyses combined with electroantennographic detection
(GC-EAD). In electroantennogram (EAG) recording male
M. privata antennae responded to the nonadecatriene. Nonadecatriene was synthesised via Kolbe electrolysis,
starting with (9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid
(linolenic acid) and propanoic acid or via an alternative
four-step method also starting from linolenic acid. In field
trials (3Z,6Z,9Z)-3,6,9-nonadecatriene proved attractive
to male moths. Thus, we conclude that (3Z,6Z,9Z)-3,6,9-
nonadecatriene is a sex pheromone component of autumn
gum moth. This component has been identified in extracts
from other geometrids in the same subfamily, Ennominae.
However, to our knowledge this is the first example where
(3Z,6Z,9Z)-3,6,9-nonadecatriene has been found in females
and also proved attractive to male moths when presented on its
own. Our results are discussed in relation to other geometrid
pheromones. 相似文献
155.
The selection and recovery of two or more solvents (i.e. co-solvents) are studied because of their importance in environmentally responsible processing. A particularly challenging problem arises when the contaminants (or solutes) are comprised of a mixture of volatile and nonvolatile compounds. The nonvolatile components present difficulties in solvent selection while the volatile components give rise to solvent recovery challenges. Traditional approaches such as the Kauri-Butanol test and predictions based on solubility parameters from regular solution theory can result in poor solvent selection when some of the contaminants are nonvolatile. A simple, graphical and rigorous procedure based on Gibbs energies of mixing for all binary mixtures of solvents and contaminants is proposed for choosing solvent/contaminant pairs. This selection procedure is based on the choice of solvent resulting in the lowest solvent/contaminant Gibbs free energy of mixing for a given contaminant. Nonvolatile contaminants are often easily separated in a single-stage flash vessel. Volatile contaminants, on the other hand, can form homogeneous or heterogeneous azeotropes with commonly used solvents, give rise to distillation boundaries and result in a challenging co-solvent recovery problem. A systematic procedure for the synthesis, design and economic analysis for co-solvent recovery is presented. Residue curve maps are used to identify distillation boundaries and to generate a conceptual process flow sheet for co-solvent recovery. Equipment sizes for the separators and auxiliaries (i.e. condensers, reboilers, decanters, etc.) are determined and capital investment, installation and operating costs are calculated. The removal of oil-water emulsions from the surface of machined metal parts using n-propyl bromide (NPB) and isopropyl alcohol (IPA) in a closed-loop degreaser is used to illustrate the proposed methodology of co-solvent selection and recovery. Analysis shows that the Kauri-Butanol test and the use of solubility parameters can result in poor solvent selection. In contrast, the proposed methodology shows that NPB is competitive with banned solvents like chlorodifluoro, fluorodichloroethane and trichloroethane and highly regulated solvents such as perchloroethylene, trichloroethylene and is a good solvent for the removal of machining oils while IPA is a good solvent for removing water. Separation of mixtures of NPB/IPA/water is difficult because of the presence of three binary and one ternary azeotrope that create three distinct distillation regions as well as regions of vapor-liquid-liquid behavior. It is shown that these distillation boundaries preclude direct water separation and that a two-distillation sequence with decantation is required to cross boundaries and recover both solvents. A variety of geometric illustrations are presented to elucidate key concepts. 相似文献
156.
Water, Air, &; Soil Pollution: Focus - 相似文献
157.
Tommy Garling Anders Bk Erik Lindberg Constantino Arce 《Journal of environmental psychology》1990,10(4)
Two experiments examined whether differences in elevation of the terrain are encoded in cognitive maps of outdoor environments. In Experiment 1, two groups of subjects who had travelled a varying number of times between a set of locations made direct estimates in metres of the differences in elevation between the locations. The results showed that subjects in both groups had knowledge of elevation but those for whom the terrain was less familiar tended to exaggerate the differences. In Experiment 2, decision times were measured of responses to the question whether one location is below or above another one. Neither for subjects who were more, nor for subjects who were less familiar with the terrain, did the decision times vary with the distances between the locations, thus failing to support the hypothesis that differences in elevation are retrieved by a process of ‘mental travel’. 相似文献
158.
159.
Burgerhout E Manabe R Brittijn SA Aoyama J Tsukamoto K van den Thillart GE 《Die Naturwissenschaften》2011,98(7):631-634
The journey of the European eel to the spawning area in the Sargasso Sea is still a mystery. Several trials have been carried
out to follow migrating eels with pop-up satellite tags (PSATs), without much success. As eels are very efficient swimmers,
tags likely interfere with their high swimming efficiency. Here we report a more than twofold increase in swimming cost caused
by a regular small satellite tag. The impact was determined at a range of swimming speeds with and without tag in a 2-m swimming
tunnel. These results help to explain why the previous use of PSATs to identify spawning sites in the Sargasso Sea was thus
far unsuccessful. 相似文献
160.
Slobodan Djordjevi? David Butler Philippe Gourbesville Ole Mark Erik PascheAuthor vitae 《Environmental Science & Policy》2011,14(7):864-873
In the context of urban flood management, resilience is equal to resisting, recovering, reflecting and responding. The variety of causes of flooding and their consequences underpin the need for increased and internationally coordinated efforts to enhance technologies and policies for dealing with floods. This paper addresses this issue and presents some novel research ideas related to resilience to flooding in urban areas, which are under development within the EU FP7 project ‘Collaborative research on flood resilience in urban areas’ (CORFU). The approach adopted in this project aims to quantify the cost-effectiveness of resilience measures and integrative and adaptable flood management plans for different scenarios of relevant drivers: urban development, socio-economic trends and climate changes. It is believed that the way in which the different models are being put together, combined with the variability of conditions in case study areas in Asia and in Europe, will ultimately enable more scientifically sound policies for the management of the consequences of urban flooding. 相似文献