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591.
H Vandenhove Y Thiry A Gommers F Goor J M Jossart E Holm T G?fvert J Roed A Grebenkov S Timofeyev T G?ufert 《Journal of environmental radioactivity》2001,56(1-2):157-184
When dealing with large-scale environmental contamination, as following the Chernobyl accident, changed land use such that the products of the land are radiologically acceptable and sustain an economic return from the land is a potentially sustainable remediation option. In this paper, willow short rotation coppice (SRC) is evaluated on radiological, technical and economic grounds for W. European and Belarus site conditions. Radiocaesium uptake was studied in a newly established and existing SRC. Only for light-texture soils with low soil potassium should cultivation be restricted to soils with contamination levels below 100-370 kBq m-2 given the TFs on these soils (5 x 10(-4) and 2 x 10(-3) m2 kg-1) and considering the Belarus exemption limit for firewood (740 Bq kg-1). In the case of high wood contamination levels (> 1000 Bq kg-1), power plant personnel working in the vicinity of ash conveyers should be subjected to radiation protection measures. For appropriate soil conditions, potential SRC yields are high. In Belarus, most soils are sandy with a low water retention, for which yield estimates are too low to make production profitable without irrigation. The economic viability should be thoroughly calculated for the prevailing conditions. In W. Europe, SRC production or conversion is not profitable without price incentives. For Belarus, the profitability of SRC on the production side largely depends on crop yield and price of the delivered bio-fuel. Large-scale heat conversion systems seem the most profitable and revenue may be considerable. Electricity routes are usually unprofitable. It could be concluded that energy production from SRC is potentially a radiologically and economically sustainable land use option for contaminated agricultural land. 相似文献
592.
Female and male reproductive interests often differ. In species in which matings are accompanied by a transfer of resources
valuable for both participants, such as nuptial prey gifts, conflicts may readily occur. Scorpionflies may use alternative
mating tactics. One is to offer a prey item (dead arthropod) to females in exchange for mating. This prey gift tactic includes
a conflict because a male must decide on whether to offer the gift rather than to fight the female and consume the gift. The
outcome may depend on the nutritional status of both males and females. Males may be more willing to give if they themselves
are satiated and the condition of the females may influence the payoff from the males’ investment. Similarly, females may
be more willing to accept food gifts if they are in poor nutritional condition. In this study of the scorpionfly Panorpa cognata, I experimentally manipulated the feeding history of both males and females. I observed the outcome of the direct interactions
that followed when males that were holding prey were approached by females. I found that well-fed males offered the food gift
sooner than males in poor nutritional condition that fed extensively on the food item before offering. Female condition had
no significant influence on whether prey items were offered by males or accepted by females. I also found that well-fed males
rarely searched for prey to pursue the prey gift tactic in courtship. Thus, the prey tactic does not seem to be the males’
first option. 相似文献
593.
Pooja?PalEmail author Himangana?Gupta Deepak?Kapur 《Mitigation and Adaptation Strategies for Global Change》2016,21(3):391-402
Steel dominates the global metal production accounting for 5 % of increase in Earth’s atmospheric carbon dioxide (CO2). Today, India is the 4th largest producer of crude steel in the world. The sector contributes around 3 % to the country’s gross domestic product (GDP) but adds 6.2 % to the national greenhouse gas (GHG) load. It accounts for 28.4% of the entire industry sector emissions, which are 23.9% of the country’s total emissions. Being a developing country, India is not obliged to cut its emissions under the Kyoto Protocol to the United Nations Framework Convention on Climate Change (FCCC), but gave voluntary commitment to reduce the emission intensity of its GDP by 20–25 % from the 2005 level by 2020. This paper attempts to find out if the Indian steel sector can help the country in fulfilling this commitment. The sector reduced its CO2 emissions per ton of steel produced by 58% from 1994 to 2007. The study generates six scenarios for future projections which show that the sector can reduce its emission intensity by 12.5 % to 63 %. But going by the conservative estimates, the sector can reduce emission intensity by 30 % to 53 %. However, actual emissions will go up significantly in every case. 相似文献
594.
Metal complexation by natural ligands is important for metal transport and distribution in surface and ground water. The goal of the work was to study the ligand exchange rate for two important metal ions in natural aquatic systems (Al, Fe) was determined using EDTA and natural organic matter (NOM) of humic type as ligands. After adding EDTA to a solution containing metal-NOM complexes, these complexes dissociated and metal-EDTA complexes were formed. Metal-NOM complexes were separated from metal-EDTA complexes with the help of size-exclusion chromatography and detected by on-line inductively coupled plasma-mass spectrometry (ICP-MS). Injecting the samples into the system over time after addition of EDTA allowed us to measure the rate of the exchange of NOM by EDTA. The experiments could be well described with a first-order rate law assuming that the dissociation of the metal-NOM complexes is the rate-determining step. The exchange rate of Fe was found to be faster than that of Al. This corresponds well with the exchange rate of water molecules from the coordination sphere of the metal ions, which is also faster for Fe than for Al. Furthermore, the UV and the fluorescence signal of the chromatograms were measured. The results indicate that no disaggregation of NOM molecules took place, although about 75-85% of the aggregate-forming metal ions exchanged NOM by EDTA in their coordination sphere. This suggests clearly the fundamental role of NOM in colloidal transport of metals and in their bioavailability. 相似文献
595.
M.?Masudul?Hassan M.?Rabiul?Islam Laurence?T.?Drzal Mubarak?A.?KhanEmail author 《Journal of Polymers and the Environment》2005,13(3):293-300
To improve the mechanical performance of natural lignocellulosic jute yarn, grafting with [3-(trimethoxysilyl) propylmethacrylate] (TMSPM) monomer has been performed on in situ UV radiation and optimized the monomer concentration (30%) and irradiation time (30 min). Effect of various amino acids (1%) as additives in TMSPM with photografted jute yarn at optimized system has been studied. The polymer loading (PL) and tensile properties like tensile strength (TS) and elongation at break (Eb) of treated samples were enhanced by incorporation of amino acids and the highest properties (TS = 300% and Eb = 386%) achieved by the sample treated with l-Arginine (Arg) with 32.5% PL value. Weak acid like 3% acetic acid and inorganic acid like 1% sulfuric acid were also incorporated in the optimized system of TMSPM grafting and compared their effect on the tensile properties with amino acid treated samples. Water absorption and weathering resistance of treated and untreated samples were also performed and treated sample showed lesser water uptake as well as less weight loss and mechanical properties as compared to untreated samples. 相似文献
596.
Alejandro?CantareroEmail authorView authors OrcID profile Jesús?Carrasco Naranjo Fabián?Casas Francois?Mougeot Javier?Vi?uela Carlos?Alonso-Alvarez 《Die Naturwissenschaften》2018,105(7-8):45
Complex body designs, such as plumage ornaments in birds, can be described by fractal geometry. These complex patterns could have a role as visual signals during courtship and social interactions, but an empirical validation in the wild is currently lacking. Here, we investigated whether the fractal dimension (FD) of a complex plumage pattern displayed by red-legged partridges Alectoris rufa could function as a potential sexual signal. We captured wild birds early in the breeding season and tested if mated and unmated birds differed in the FD of their conspicuous melanin-based black bib. We also tested if the FD of the black bib was correlated within the pair, looking for evidence of assortative mating based on the expression of this trait. We simultaneously assessed similar effects in other ornamental traits (black bib size, white throat patch and black flank band surface, redness of the eye rings and bill). Mated birds showed higher black bib FD values than unmated ones. Mated males, but not females, also displayed a larger black bib. Moreover, the black bib FD (but not the trait size) and the white throat patch surface showed assortative mating. Finally, females with higher black bib FD showed smaller black flank band surface, suggesting a trade-off in the expression of the two melanin-pigmented plumage traits. This provides unique and novel indication for the shape complexity of a pigmented trait, here described by its fractal dimension, to be potentially under sexual selection in a wild animal. 相似文献
597.
The invertebrate neuromodulator octopamine is known to be involved in bees' associative learning, enhancing the responsiveness of a bee to a conditioned stimulus. In this study, we tested the effect of octopamine on the choice behavior of free-flying bumblebees using a two-phase experiment in an array of artificial flowers. During the first phase of the experiment, the bee was allowed to collect octopamine-laden sugar water from two types of equally rewarding flowers (yellow versus blue). In the second phase, one type of flower was set to be unrewarding. The behavior of the bee (proportion of visits to the unrewarding flowers) over the two phases was fitted to a sigmoid regression model. Our results show that octopamine had no significant effect on the bees' equilibrium choice or on the overall rate of the behavioral change in response to the change in reward. Rather, octopamine significantly affected the time interval between the change in reward status and the initiation of behavioral change in the bee. 相似文献
598.
An assessment of endocrine disrupting activity changes during wastewater treatment through the use of bioassays and chemical measurements. 总被引:1,自引:0,他引:1
J?rg E Drewes Jocelyn Hemming Sarah J Ladenburger James Schauer William Sonzogni 《Water environment research》2005,77(1):12-23
The objective of this study was to assess the removal efficiencies of secondary wastewater treatment processes for compounds causing endocrine disrupting activity. The study used bioassays and chemical measurements, such as gas chromatography with mass spectrometry and enzyme immunosorbent assays. A total of seven full-scale water reclamation facilities using different unit operations and two pilot-scale membrane bioreactors were examined. Findings of this study imply that estrogenic disrupting activity in primary effluent is mainly caused by two steroidal hormones (17beta-estradiol and estriol) and, to a lesser extent, by synthetic chemicals, such as bisphenol A, 4-nonylphenol, and 4-tert-octylphenol. During secondary treatment, steroidal hormones were removed to a higher degree than nonylphenol and bisphenol A. The total estrogenic activity was removed by an average of 96%. The remaining concentrations of targeted steroids in secondary effluents, except for estriol, still had the potential to elicit a positive response in the human breast cell cancer assay. For the majority of facilities, the remaining activity was likely attributed to residual concentrations of two steroidal hormones (17beta-estradiol and estriol). 相似文献
599.
Hua?Bai Siyu?Zeng Xin?Dong Jining?ChenEmail author 《Frontiers of Environmental Science & Engineering》2013,7(5):746-755
This paper discusses the use of substance flow analysis (SFA) as a tool to support quantified research on urban drainage systems. Based on the principle of mass balance, a static substance flow model is established to describe and examine the routes and intensities of water, chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) for a representative hypothetical city (RH city) in China, which is a devised and scaled city using statistical characteristics of urban circumstances at the national level. It is estimated that the annual flux of water, COD, TN and TP through the urban drainage system in 2010 was 55.1 million m3, 16037.3 t, 1649.5 t and 209.7 t, respectively. The effluent of wastewater treatment plant (WWTP) was identified as the most important pathway for pollutant emissions, which contributed approximately 60% of COD, 65% of TN and 50% of TP to receiving water. During the wastewater treatment process, 1.0 million m3, 7042.5 t, 584.2 t and 161.4 t of the four studied substances had been transmitted into sludge, meanwhile 3813.0 t of COD and 394.0 t of TN were converted and emitted to the atmosphere. Compared with the representative hypothetical city of 2000, urban population and the area of urban built districts had expanded by approximately 90% and 80% respectively during the decade, resulting in a more than threefold increase in the input of substances into the urban drainage system. Thanks to the development of urban drainage systems, the total loads of the city were maintained at a similar level. 相似文献
600.
M.?Purenovi? J.?Perovi? A.?Boji?Email author T.?An?elkovi? D.?Boji? 《Environmental Chemistry Letters》2004,2(2):59-63
We studied the removal of cadmium and copper from industrial wastewaters by a microalloyed aluminium composite. The composite was highly efficient, resulting in water concentrations of cadmium and copper below the maximal allowed concentrations for drinking water. Moreover, our results show that the removal mechanism is mainly based on reduction and coprecipitation, since Cd and Cu were removed from the wastewater in reduced forms as metals and hydroxides.Selected article from the Regional Symposium on Chemistry and Environment, Krusevac, Serbia, June 2003, organised by Dr. Branimir Jovancicevic 相似文献