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601.
Ma?gorzata Grodzińska-Jurczak Hanna Zakowska Adam Read 《Waste management & research》2004,22(3):212-223
In recent years the issue of the municipal waste in Poland has become increasingly topical, with a considerable rise in the waste generation, much of which can be attributed to a boom in product packaging (mainly plastic). The annual production of plastics packaging has been constantly increasing over the last 20 to 30 years, and now exceeds 3.7 million tons. Due to a lack of processing technologies and poorly developed selective segregation system, packaging waste is still treated as a part of the municipal solid waste (MSW) stream, most of which is landfilled. As a result of Poland's access to the European Union, previous legal regulations governing municipal waste management have been harmonized with those binding on the member countries. One of the main changes, the most revolutionary one, is to make entrepreneurs liable for environmental risks resulting from the introduction of packaging to the market, and for its recycling. In practice, all entrepreneurs are to ensure recovery, and recycling, of used packaging from products introduced to the market at the required level. In recent year, the required recycling levels were fulfilled for all types of materials but mainly by large institutions using grouped and transport packaging waste for that matter. Household packaging gathered in the selective segregation system at the municipalities was practically left alone. This paper is an attempt to describe the system and assess the first year of functioning of the new, revamped system of packaging waste management in Poland. Recommendations are made relating to those features that need to be included in packaging waste management systems in order to maximize their sustainability and harmonization with the EU legal system. 相似文献
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The free amino acid content in needles of Norway spruce trees (about 45-year-old) was determined by means of HPLC. The studied trees have been growing at a forestry site in the Black Forest which is characterized by a high impact of ozone and magnesium deficiency. Measurements were carried out on visibly healthy and on damaged trees on several dates during two vegetation periods and during the course of a day. The amino acids occurring at the highest concentrations were glutamate, arginine, aspartate, and glutamine. The typical seasonal changes in the content of free amino acids, with their minimum during summer, were disturbed in the needles of the damaged trees. Particularly in summer and autumn the damaged trees showed increased levels of total amino acids and of most single amino acids. During the course of a day, the needles of the damaged trees showed a reduced amplitude in diurnal variations with the absolute level almost always higher in comparison to that of the undamaged trees. The results suggest that a shift in protein turnover towards enhanced degradation has taken place. 相似文献
604.
The expected impact of the “Peace Conduit” project (the Red Sea - Dead Sea pipeline) on the Dead Sea
Ittai?GavrieliEmail author Amos?Bein Aharon?Oren 《Mitigation and Adaptation Strategies for Global Change》2005,10(4):759-777
The Dead Sea is a severely disturbed ecosystem, greatly damaged by anthropogenic intervention in its water balance. During
the 20th century, the Dead Sea level dropped by more than 25 meters, and presently (2003) it is at about 416 meters below
mean sea level. This negative water balance is mainly due to the diversion of water from the catchment area of the lake by
Israel, Jordan and Syria. During the 2002 World Summit on Sustainable Development Israel and Jordan jointly announced their
interest in saving the Dead Sea by constructing the “Peace Conduit” that will pipe water from the Red Sea to the Dead Sea.
The inflow of seawater (or reject brine after desalinization) into the Dead Sea will have a major impact on its limnology,
geochemistry and biology. During the filling stage, relatively diluted surface water will form and the rate of evaporation
will therefore increase. Dilution of the surface water will most likely result in microbial blooming whose duration is not
known, while the lower water layer is likely to develop reducing conditions, including bacterial sulfate reduction and presence
of hydrogen sulfide (H2S). Mixing between the calcium-rich Dead Sea brine and the sulfate-rich seawater will result in gypsum precipitation (CaSO4⋅ 2H2O). Once the target level is reached, inflow will be outbalanced by evaporation and salinity of the surface water will increase
due to accumulation of seawater-salts. The water column will re-mix when the density of the surface water will equal that
of the lower water column. In spite of its large volume and high salinity relative to that of the inflowing water, over the
long run the composition of this unique lake will change. Before a decision is made on the planning and construction of the
Conduit, it is essential that the long term evolution and characteristics of the “renewed” Dead Sea be known and anticipated
changes examined. Once decided upon, the planning and construction of the Conduit should be conducted so as to minimize possible
negative impacts of seawater introduction on the Dead Sea. This can only be achieved through a thorough understanding of the
expected changes in the limnological physical/chemical characteristics of the Dead Sea and its unique brine. 相似文献
605.
Ernst Mayr: the doyen of twentieth century evolutionary biology 总被引:1,自引:0,他引:1
Hölldobler B 《Die Naturwissenschaften》2004,91(6):249-254
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Al/Si configurations in some natural and synthetic Rb-feldspars have been examined carefully by EMPA and XPS analyses. Our results indicate that a small amount of H2O and excess Si and Al are incorporated in hydrothermally synthesized Rb-feldspar. The quantities of excess Al are 0.056 atoms per formula unit and are negatively correlated with those of the Rb, suggesting the presence of excess Al occupying non-tetrahedral sites in feldspar structures. This leads to incorporation of Al(Al3Si)O8 endmember into Rb-feldspars, estimated as one appropriate endmember indication for unusual chemistry of feldspars. In addition, Si2p, Al2p and O1s XPS signals of Rb-feldspars shift drastically toward the higher energy side than those of any natural feldspars. These provide conclusive evidence not only for existence of perceptible excess Si and Al, but also for Al at both extra-framework and tetrahedral sites in feldspar structures. 相似文献
609.
The mechanism of caste differentiation in a social aphid Tuberaphis styraci, which has a sterile soldier caste in the 2nd instar, was investigated using an artificial diet rearing system. High aphid density induced soldier production. Combinatorial prenatal and postnatal density treatments revealed that (1) either prenatal high density or postnatal high density is sufficient for soldier induction; (2) thus, embryos in the maternal body and newborn 1st instar nymphs are both responsive to high density; (3) the combination of prenatal high density and postnatal high density enhances soldier differentiation in a synergistic manner; and (4) the final determination of soldier differentiation occurs postnatally, probably at a late 1st instar stage. This study first throws light on the developmental aspects of caste differentiation in a social aphid. 相似文献
610.
Food sharing among unrelated same-sex individuals has received considerable interest from primatologists and evolutionary biologists because of its apparent altruistic nature and implications for the evolution of complex social cognition. In contrast to primates, food sharing in birds has received relatively little attention. Here we describe three types of food sharing in jackdaws, with the initiative for the transfer either with the receiver or the giver. The latter situation is of particular interest because the food transfer takes place through active giving. Compared to primates, jackdaws show high rates of food sharing. Finally we discuss the implications of food sharing in jackdaws, and in birds in general. 相似文献