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991.
992.
The objective of this work is to examine to what degree the integration between R&D and environmental departments facilitates the achievement of an environmental practice-derived competitive advantage. With this aim, we surveyed 110 International Organization for Standardization (ISO) 14001 certified factories. The results reveal that the integration of environmental action into the R&D department enhances a company's reputation through the product quality and image. Moreover, the said integration positively influences the company's overall innovative capability and, hence, its ability to penetrate international markets. 相似文献
993.
Alex Maurício Araújo Daniel Arraes de Alencar Valença Aigbokhan Isaiah Asibor Pedro André Carvalho Rosas 《Environmental Fluid Mechanics》2013,13(1):33-50
This work proposes an approach to simulate wind flow fields around an urban environment with the aim of evaluating the potential impact of buildings on the general wind patterns and power production using the current generation of commercial wind turbines. The simulation process was performed with the aid of accessible computational tools that can potentially render the proposed procedure applicable in other cases of interest. The roughness of the urban environment was defined as the association of roughness map, topography, and an alternative process for obtaining the volumetry of buildings. A case study was conducted in a region located at the district of Boa Viagem (Recife-PE) for assessing the applicability of the approach. Scenarios were designed in order to simulate wind flow patterns and pre-identify sites that have suitable wind energy potential for electric power production by investigating the combination of wind speed magnitude and turbulence intensity. From the results obtained, it was possible to identify zones of potential wind sources that are not detected in classical wind atlas probably due to the influence of the built environment on local wind flow patterns. 相似文献
994.
Species employ diverse strategies to cope with natural disturbance, but the importance of these strategies for maintaining tree species diversity in forests has been debated. Mechanisms that have the potential to promote tree species coexistence in the context of repeated disturbance include life history trade-offs in colonization and competitive ability or in species' ability to survive at low resource conditions and exploit the temporary resource-rich conditions often generated in the wake of disturbance (successional niche). Quantifying these trade-offs requires long-term forest monitoring and modeling. We developed a hierarchical Bayes model to investigate the strategies tree species employ to withstand and recover from hurricane disturbance and the life history trade-offs that may facilitate species coexistence in forests subject to repeated hurricane disturbance. Unlike previous approaches, our model accommodates temporal variation in process error and observations from multiple sources. We parameterized the model using growth and mortality data from four censuses of a 16-ha plot taken every five years (1990-2005), together with damage data collected after two hurricanes and annual seed production data (1992-2005). Species' susceptibilities to hurricane damage as reflected by changes in diameter growth and fecundity immediately following a storm were weak, highly variable, and unpredictable using traditional life history groupings. The lower crowding conditions (e.g., high light) generated in the wake of storms, however, led to greater gains in growth and fecundity for pioneer and secondary-forest species than for shade-tolerant species, in accordance with expectation of life history. We found moderate trade-offs between survival in high crowding conditions, a metric of competitive ability, and long-distance colonization. We also uncovered a strong trade-off between mean species fecundity in low crowding conditions, a metric of recovery potential, and competitive ability. Trade-offs in competitive and colonization ability, in addition to successional niche processes, are likely to contribute to species persistence in these hurricane-impacted forests. The strategies species employ to cope with hurricane damage depend on the degree to which species rely on sprouting, repair of adult damage, changes in demographic rates in response to enhanced resource availability after storms, or long-distance dispersal as recovery mechanisms. 相似文献
995.
Radionuclides from the U and Th natural series are present in alkaline rocks, which are used as feedstock in Brazil for the
production of raw phosphoric acid, which can be considered as a NORM (naturally occurring radioactive material). As a result
of the purification of raw phosphoric acid to food-grade phosphoric acid, two by-products are generated, i.e., solid and liquid
wastes. Taking this into account, the main aim of this study was to evaluate the fluxes of natural radionuclide in the production
of food-grade phosphoric acids in Brazil, to determine the radiological impact caused by ingestion of food-grade phosphoric
acid, and to evaluate the solid waste environmental hazards caused by its application in crop soils. Radiological characterization
of raw phosphoric acid, food-grade phosphoric acid, solid waste, and liquid waste was performed by alpha and gamma spectrometry.
The 238U, 234U, 226Ra, and 232Th activity concentrations varied depending on the source of raw phosphoric acid. Decreasing radionuclides activity concentrations
in raw phosphoric acids used by the producer of the purified phosphoric acid were observed as follows: Tapira (raw phosphoric
acid D) > Catal?o (raw phosphoric acids B and C) > Cajati (raw phosphoric acid A). The industrial purification process produces
a reduction in radionuclide activity concentrations in food-grade phosphoric acid in relation to raw phosphoric acid produced
in plant D and single raw phosphoric acid used in recent years. The most common use of food-grade phosphoric acid is in cola
soft drinks, with an average consumption in Brazil of 72 l per person per year. Each liter of cola soft drink contains 0.5 ml
of food-grade phosphoric acid, which gives an annual average intake of 36 ml of food-grade phosphoric acid per person. Under
these conditions, radionuclide intake through consumption of food-grade phosphoric acid per year per person via cola soft
drinks is not hazardous to human health in Brazil. Considering these annual additions of 238U, 226Ra, 232Th and 40K, and since these radionuclide should be homogeneously distributed in the upper 10 cm of soils with an assumed apparent density
of 1.5 g/cm3, a maximum increase of 0.19 ± 0.03 Bq kg−1 of soil is expected for 238U and 234U. Thus, the addition of solid waste as phosphate fertilizers to Brazilian agricultural soils does not represent a hazard
to the ecosystem or to human health. 相似文献
996.
Patinha C Reis AP Dias C Cachada A Adão R Martins H Ferreira da Silva E Sousa AJ 《Environmental geochemistry and health》2012,34(2):213-227
Previous environmental biomonitoring studies indicated higher environmental lead (Pb) pollution levels at the districts of
Aveiro and Leiria (Portugal). In evaluating the risk for human health, which is associated with contaminated soils after oral
uptake, total soil concentrations have generally been held against criteria established from toxicological studies based upon
the assumption that the uptake of the contaminant is similar in the toxicological studies and from the soils assessed. This
assumption is not always valid, as most toxicological studies are carried out with soluble forms of the contaminants, whereas
many soil contaminants are or become embedded in the soil matrix and thus exhibit limited availability. This study intends
to estimate the soluble fraction of Pb in the soils from central Portugal, and to assess the bioaccessibility of Pb and, hence,
infer exposure and risk for human health. Yet, as the physical–chemical properties of the soil exert some control over the
solubility of Pb in the surface environment, the relation between such soil properties and the estimated soluble and/or bioaccessible
fractions of Pb is also investigated. Other objective, with a more practical nature, was to give some contribution to find
a suitable in vitro mimetic of the gastrointestinal tract environment. The results indicate relatively low total metal concentrations
in the soils, even if differences between regions were observed. The Aveiro district has the higher total Pb concentration
and the metal is in more soluble forms, that is, geoavailable. Soils with higher concentrations of soluble Pb show higher
estimates of bioaccessible Pb. Soil pH seems to influence human bioaccessibility of Pb. 相似文献
997.
Míguez DM Huertas R Carrara MV Carnikián A Bouvier ME Martínez MJ Keel K Pioda C Darré E Pérez R Viera S Massa E 《Environmental geochemistry and health》2012,34(2):199-205
Bioassays of two sites along the Rio Negro in Uruguay indicate ecotoxicity, which could be attributable to trace concentrations of lead in river sediments. Monthly samples at two sites at Baygorria and Bonete locations were analyzed for both particle size and lead. Lead was determined by atomic spectrometry in river water and sediment and particle size by sieving and sedimentation. Data showed that Baygorria's sediments have greater percentage of clay than Bonete's (20.4 and 5.8%, respectively). Lead was measurable in Baygorria's sediments, meanwhile in Bonete's, it was always below the detection limit. In water samples, lead was below detection limit at both sites. Bioassays using sub-lethal growth and survival test with Hyalella curvispina amphipod, screening with bioluminescent bacteria Photobacterium leiognathi, and acute toxicity bioassay with Pimephales promelas fish indicated toxicity at Baygorria, with much less effect at Bonete. Even though no lethal effects could be demonstrated, higher sub-lethal toxicity was found in samples from Baygorria site, showing a possible concentration of the contaminant in the clay fraction. 相似文献
998.
A theoretical model, based on linear stability analysis, is proposed to predict the onset of natural convection in lakes and
reservoirs due to night time cooling. To such purpose, the system was modelled as a initially quiescent deep Boussinesq fluid
reservoir, whose upper boundary temperature changes sinusoidally. From scaling analysis, it is found that critical onset times
for convection are proportional to R
−2/7, where R is a Rayleigh number including fluid properties and forcing frequency. The proportionality constant was found, from the solution
of an eigenvalue problem, as a function of the Prandtl number. The onset time for convection was easily observed from experiments
and quantitatively detected as a rapid increase of the RMS of the computed velocity field obtained using PIV. In this controlled
conditions, differences close to 10% between predicted and observed times for the start of the convective flow was found.
It is apparent from the present set of results that predictions are reasonable. 相似文献
999.
Diogo Rúben Neves Sara Rodrigues Concei??o Juana Fortes Maria Teresa Reis Jo?o Alfredo Santos Rui Capit?o 《Journal of Coastal Conservation》2012,16(4):489-501
This paper describes a first approach on the risk assessment in port navigation using GUIOMAR, an integrated system for port and coastal engineering modelling developed at the National Civil Engineering Laboratory (LNEC), Portugal, using a GIS software environment. A set of automatic procedures was designed to include a new methodology based on the amplitude of the wave-induced vertical movement of a ship along its trajectory. In this methodology, the risk in port navigation is assessed on the basis of a combination of the probability of exceedance of a pre-set threshold for the ship??s vertical movements and its consequences. To test the new procedures, a set of sea wave records obtained at the Sines wave-buoy from 1988 to 2002 was transferred into Sines Port using two numerical models of sea wave propagation and deformation (SWAN and DREAMS), included in the GUIOMAR system. The numerical model WAMIT was used for estimating the wave-induced ship??s vertical movements inside the port. By applying the new procedures, automatic generation of risk maps was carried out for navigation in the vicinity of the West breakwater of the Port of Sines. The recent developments contribute towards a more versatile and efficient GUIOMAR system, which results in a more adequate tool to support decision-making processes in port and coastal management. 相似文献
1000.
In the shrimp Crangon crangon, an important fishery resource and key species in the southern North Sea, we studied temporal variations in size, biomass
(dry weight, W) and chemical composition (C, N, protein and lipid) of eggs in an initial embryonic stage. Data from 2 years, 1996 and 2009,
consistently revealed that egg size and biomass varied seasonally, with maxima at the beginning of the reproductive season
(January), decreasing values throughout spring, minima in June–July, and a slight increase thereafter. This cyclic pattern
explains why “Winter eggs” are on average larger and heavier than “summer eggs”. Using a modelling approach, we estimated
the duration of oogenesis in relation to seasonally changing seawater temperatures. According to an additive model of multiple
explanatory variables, the C content per newly laid egg showed in both years a highly significant negative relationship with
day length (r2 = 0.38 and 0.40, respectively; P < 0.0001), a weak positive relationship with temperature (r2 = 0.08 and 0.09; P < 0.05), and a weak negative relationship with phytoplankton biomass (r2 = 0.11 and 0.12; P < 0.05) at the estimated time of beginning oogenesis. Phenotypic plasticity in initial egg size and biomass is interpreted
as an adaptive reproductive trait that has evolved in regions with strong seasonality in plankton production and periods of
larval food limitation. In contrast to biomass per egg, the percentage chemical composition remained similar throughout the
reproductive period. Both the absolute and percentage values also showed significant interannual variations, which caution
against generalizations based on short-term studies of reproductive traits of C. crangon and other species of shrimp. 相似文献