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J. J. M. Cuppen G. F. Wiegertjes H. W. J. Lobee H. F. J. Savelkoul M. A. Elmusharaf A. C. Beynen H. N. A. Grooten W. Smink 《The Environmentalist》2007,27(4):577-583
A hypothesis is proposed how Low Frequency Electromagnetic Field (LF EMF) exposure can stimulate an immune response, based
on recent insights in immunology. We hypothesize that the Immunent EMF treatment induces mild stress to cells, which then
produce cytokines that function as alarms or so called danger signals for the immune system. In this way EMF treatment takes
the place of multiplying pathogens, and the damage these cause, in the triggering of an immune response. In a first series
of experiments in␣vitro common carp head kidney-derived phagocytes were used to determine ROS production as a measure for
immune activation. Exposure to LF EMF signals (200–5,000 Hz) at 5 μT or 1.5 mT led to 42 or 33% increase in immune activity,
respectively, compared to negative control values. EMF could also additionally stimulate chemically pre-stimulated samples
up to 18% (5 μT) or 22% (1.5 mT). Significance of increase in ROS production in the total series was: p < 0.0001. In a second series of experiments in␣vitro commercial goldfish were used. Groups of fish were housed under equal
conditions in at least four control tanks and 8–16 EMF-exposed tanks. Exposure was done with a predominantly vertical field
at field strengths (rms) between 0.15 and 50 μT. Without treatment mortality was about 50% after 18 days, while the treatment
at 5 μT reduced it to 20% on average. At field strengths 0.15, 0.5, 1.5, 5, 15 and 50 μT an equally strong effect was found.
Reducing the field strength to 0.05, 0.06, 0.01 and 0.003 μT showed a gradually decreasing effect, which only at 0.003 μT
is no longer statistically significant. Finally, in␣vitro experiments were done with 560 commercial broiler chickens exposed
to infection pressure from coccidiosis. EMF exposure at 6.5 μT reduced intestinal lesions by 40% and improved feed conversion
by 8%. 相似文献
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G. J. Duffy BE PhD MAIE R. D. Lanauze BE PhD MAIE J. W. Kable BSc 《Environmental geochemistry and health》1981,3(4):103-110
All Australian coal for export is washed — that is, the low-grade high-ash material is separated out and disposed of at the washery site. The coarse rejects are generally placed in embankments and the tailings are pumped into settling ponds. These methods of waste disposal can create environmental problems. In addition, they represent a significant energy loss, because about one-third of the waste material is combustible and is thus a potentially valuable source of energy. Laboratory studies at the CSIRO Division of Fossil Fuels at North Ryde, New South Wales, have shown that energy can be successfully recovered from washery wastes by the process of fluidized-bed combustion. A pilot fluidized-bed combustor, with a capacity of 2 tonnes/hour, is undergoing prolonged trial at the Clutha washery near Camden, New South Wales, in a joint project between the Joint Coal Board and CSIRO. The results from the pilot plant tests have provided the basis for a conceptual design and feasibility study for a full-scale tailings treatment plant. This study has indicated that fluidized-bed combustion:
- offers an environmentally attractive and economically competitive alternative to the disposal of tailings in settling ponds, and
- can be used to generate large quantities of energy from the wastes, reducing the energy lost in coal washing from around 16% to 6% of the coal mined.
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Hur J Schlautman MA Karanfil T Smink J Song H Klaine SJ Hayes JC 《Environmental monitoring and assessment》2007,132(1-3):171-187
The Reedy River in South Carolina is affected by the urban area of Greenville, the third most populous city in the state,
and by the effluents from two large-scale municipal wastewater treatment plants (WWTPs) located on the river. Riverine water
chemistry was characterized using grab samples collected annually under spring season baseflow conditions. During the 4-year
time period associated with this study, climatic variations included two severe drought spring seasons (2001 and 2002), one
above-normal precipitation spring season (2003), and one below-normal precipitation spring season (2004). The influence of
drought and human activities on the baseflow chemistry of the river was evaluated by comparing concentrations of dissolved
anions, total metals, and other important water chemistry parameters for these different years. Concentrations of copper and
zinc, common non-point source contaminants related to urban activities, were not substantially elevated in the river within
the urban area under baseflow conditions when compared with headwater and tributary samples. In contrast, nitrate concentrations
increased from 1.2–1.6 mg/l up to 2.6–2.9 mg/l through the urban stream reach. Concentrations of other major anions (e.g.,
sulfate, nitrate) also increased along the reach, suggesting that the river receives continuous inputs of these species from
within the urban area. The highest concentrations of major cations and anions typically were observed immediately downstream
from the two WWTP effluent discharge locations. Attenuation of nitrate downstream from the WWTPs did not always track chloride
changes, suggesting that nitrate concentrations were being controlled by biochemical processes in addition to physical processes.
The relative trends in decreasing nitrate concentrations with downstream distance appeared to depend on drought versus non-drought
conditions, with biological processes presumably serving as a more important control during non-drought spring seasons. 相似文献
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Tailings containing toxic qualities of heavy metals are a potential source of pollution. Stabilisation by vegetative methods have been found the most effective. In an attempt to vegetate tailings dams it has been noted that while certain milky latex containing plants can be grown without any preconditioning of the soil, almost any plant can be grown after proper conditioning. However, the plants grown there cannot be consumed by humans or cattle due to their high metal content. 相似文献
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