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951.
Al-Tayar NG Nagaraja P Vasantha RA Shresta AK 《Environmental monitoring and assessment》2012,184(1):181-191
A simple, rapid, and sensitive method involving the interaction of 2,4-dinitrophenylhydrazine with imipramine hydrochloride
in presence of vanadium (V) in sulfuric acid medium has been proposed for the determination of vanadium. The purple-colored
product developed showed an absorption maximum at 560 nm and was stable for 24 h. The working curve was linear over the concentration
range of 0.1–2.8 μg ml − 1, with sensitivity of detection of 0.0124 μg ml − 1. Molar absorptivity and Sandell’s sensitivity were found to be 2.6 × 104 l/mol cm and 0.0039 μg cm − 1, respectively. The accuracy of the proposed method was assessed by Student’s t test and variance ratio F test, and the results were on par with the reported method. The method was successfully used in the determination of V in
water, human urine, soil, and plant samples, and it was free from interference by various concomitant ions. 相似文献
952.
Mohamed F. Yassin 《Environmental monitoring and assessment》2012,184(6):3749-3760
This paper presents a model for coupling the statistics of wind velocity distribution and atmospheric pollutant dispersion.
The effect of wind velocity distribution is modeled as a three-dimensional finite-impulse response (3D-FIR) filter. A phase
space representation of the 3D-FIR filter window is discussed. The resulting pollutant dispersion is the multiplication in
the phase space of the 3-D Fourier transform of the pollutant concentration and the volume described by the filter window
coefficients. The shape of the filter window in the phase space enables representing such effects as vortex shedding thermal
currents, etc. The impact of spatial distribution of the sensors on the resulting pollutant spatial distribution and the 3-D
FIR filter model employed also discuss. The case of a neutrally buoyant plume emitted from an elevated point source in a turbulent
boundary layer considers. The results show that wind turbulence is an important factor in the pollutant dispersion and introduces
expected random fluctuations in pollutant distribution and leads to spreading the distribution due to wind mixing. 相似文献
953.
Smederevac-Lalić M Pešić R Cvejić S Simonović P 《Environmental monitoring and assessment》2012,184(5):2633-2646
The multidisciplinary socio-economic study of fisheries in the bordering part of the Danube River between Serbia and Croatia (at the following sites: Apatin, Ba?ka Palanka, Ba?ko Novo Selo, Bezdan, and Sombor) that was performed in order to investigate various aspects of fish resource utilization (management, policy of protection and exploitation of freshwater fishery resources, present fisheries legislation, catch statistics), was realized during 2004 and 2005. Data were collected via survey with a structured interview. Socio-economic circumstances, together with ecological factors, have had an influence on the fish stock and number of commercial fishermen. Awareness of the occurring problems, both economic and ecological ones, is apparent, regardless of whether it is assessed in the field of commercial or recreational fishing. Fishery sector in Serbia is in a prolonged process of transition, with the enforcement of fishing regulations, but also the lack of control that leaves space for illegal commercial fishing. The statements, consciousness, experience and behavior of commercial fishermen represent a good basis for planning the sustainable development of fishing in this section of the Danube River. 相似文献
954.
Yutaka Tamaura 《Ambio》2012,41(2):108-111
When a concentrated solar beam is irradiated to the ceramics such as Ni-ferrite, the high-energy flux in the range of 1500–2500 kW/m2 is absorbed by an excess Frenkel defect formation. This non-equilibrium state defect is generated not by heating at a low heating-rate (30 K/min), but by irradiating high flux energy of concentrated solar beam rapidly at a high heating rate (200 K/min). The defect can be spontaneously converted to chemical energy of a cation-excess spinel structure (reduced-oxide form) at the temperature around 1773 K. Thus, the O2 releasing reaction (α-O2 releasing reaction) proceeds in two-steps; (1) high flux energy of concentrated solar beam absorption by formation of the non-equilibrium Frenkel defect and (2) the O2 gas formation from the O2? in the Frenkel defect even in air atmosphere. The 2nd step proceeds without the solar radiation. We may say that the 1st step is light reaction, and 2nd step, dark reaction, just like in photosynthesis process. 相似文献
955.
Interacting forces of climate change and globalization are transforming the Arctic. Triggered by a non-linear shift in sea
ice, this transformation has unleashed mounting interest in opportunities to exploit the region’s natural resources as well
as growing concern about environmental, economic, and political issues associated with such efforts. This article addresses
the implications of this transformation for governance, identifies limitations of existing arrangements, and explores changes
needed to meet new demands. It advocates the development of an Arctic regime complex featuring flexibility across issues and
adaptability over time along with an enhanced role for the Arctic Council both in conducting policy-relevant assessments and
in promoting synergy in interactions among the elements of the emerging Arctic regime complex. The emphasis throughout is
on maximizing the fit between the socioecological features of the Arctic and the character of the governance arrangements
needed to steer the Arctic toward a sustainable future. 相似文献
956.
Beatriz Arroyo François Mougeot Vincent Bretagnolle 《Behavioral ecology and sociobiology》2001,50(2):109-115
We assessed whether colonial breeding allows individuals to decrease their investment in predator defence, by presenting decoys of owls, foxes and crows to Montagu's harrier, Circus pygargus. Decoy detection increased with colony size, as did the number of individuals mobbing the decoy. The number of mobbers was greater for predators potentially risky for the adults (owl or fox) than for non-dangerous predators (crow). Recruits (breeding neighbours, fledglings and non-breeders) were present a lower percentage of the time, and attacked and alarm called less frequently than tested individuals. Nevertheless, the overall attack rate on the predator increased with the number of mobbers. When the size of the mobbing group increased, individuals were more likely to attack predators that represented a risk for adults, but did so less intensively and with a lower frequency of close dives. Thus, coloniality decreased the individual costs of defence in terms of risk taken, whilst enhancing defence efficacy. Birds alarm called more intensively when presented with dangerous predators than with the crow. The number of recruits significantly increased with increasing alarm rate of the tested individuals, even when taking colony size into account. Furthermore, the alarm rate of the tested birds also had a significant effect on the proportion of recruits that engaged in attacks against dangerous predators but not against the crow. The higher recruitment and attack rates for dangerous predators were thus apparently modulated through alarm calling. We discuss whether tested birds may manipulate recruits' behaviour to lessen their own risk. 相似文献
957.
Mohanraj R Solaraj G Dhanakumar S 《Environmental science and pollution research international》2011,18(5):764-771
Background
Airborne fine particulates (PM 2.5) and its associated polycyclic aromatic hydrocarbons (PAHs) are reportedly hazardous in urban environment due to the presence of multiple emission sources. 相似文献958.
de Nazelle A Nieuwenhuijsen MJ Antó JM Brauer M Briggs D Braun-Fahrlander C Cavill N Cooper AR Desqueyroux H Fruin S Hoek G Panis LI Janssen N Jerrett M Joffe M Andersen ZJ van Kempen E Kingham S Kubesch N Leyden KM Marshall JD Matamala J Mellios G Mendez M Nassif H Ogilvie D Peiró R Pérez K Rabl A Ragettli M Rodríguez D Rojas D Ruiz P Sallis JF Terwoert J Toussaint JF Tuomisto J Zuurbier M Lebret E 《Environment international》2011,37(4):766-777
959.
Use of Descriptors of Ecosystem Functioning for Monitoring a National Park Network: A Remote Sensing Approach 总被引:1,自引:0,他引:1
Baseline assessments and monitoring of protected areas are essential for making management decisions, evaluating the effectiveness
of management practices, and tracking the effects of global changes. For these purposes, the analysis of functional attributes
of ecosystems (i.e., different aspects of the exchange of matter and energy) has advantages over the traditional use of structural
attributes, like a quicker response to disturbances and the fact that they are easily monitored through remote sensing. In
this study, we described the spatiotemporal patterns of different aspects of the ecosystem functioning of the Spanish national
parks and their response to environmental changes between 1982 and 2006. To do so, we used the NOAA/AVHRR-GIMMS dataset of
the Normalized Difference Vegetation Index (NDVI), a linear estimator of the fraction of photosynthetic active radiation intercepted
by vegetation, which is the main control of carbon gains. Nearly all parks have significantly changed during the last 25 years:
The radiation interception has increased, the contrast between the growing and nongrowing seasons has diminished, and the
dates of maximum and minimum interception have advanced. Some parks concentrated more changes than others and the degree of
change varied depending on their different environmental conditions, management, and conservation histories. Our approach
identified reference conditions and temporal changes for different aspects of ecosystem functioning, which can be used for
management purposes of protected areas in response to global changes. 相似文献
960.
Land use conflicts are becoming increasingly apparent from local to global scales. Surface gold mining is an extreme source
of such a conflict, but mining impacts on local livelihoods often remain unclear. Our goal here was to assess land cover change
due to gold surface mining in Western Ghana, one of the world’s leading gold mining regions, and to study how these changes
affected land use systems. We used Landsat satellite images from 1986–2002 to map land cover change and field interviews with
farmers to understand the livelihood implications of mining-related land cover change. Our results showed that surface mining
resulted in deforestation (58%), a substantial loss of farmland (45%) within mining concessions, and widespread spill-over
effects as relocated farmers expand farmland into forests. This points to rapidly eroding livelihood foundations, suggesting
that the environmental and social costs of Ghana’s gold boom may be much higher than previously thought. 相似文献