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Stabilization of phosphorus (P) in sewage sludge (biosolids) to reduce water-soluble P concentrations is essential for minimizing P loss from amended soils and maximizing the capacity of the soil to safely serve as an outlet for this waste material. The chemical form at which P is retained in biosolids stabilized by Al(2)(SO(4))(3) x 18H(2)O (alum) or FeSO(4) x 7H(2)O (FeSul) was investigated by scanning electron microscopy (SEM) equipped with energy-dispersive X-ray elemental spectrometry (EDXS) and by X-ray diffraction (XRD). Both treatments resulted in the formation of a Ca-P phase, probably brushite. Phosphorus was further retained in the alum-treated biosolids by precipitation of an Al-P phase with an Al/P molar ratio of about 1:1, while in the FeSul-treated biosolids, P was retained by both precipitation with Fe/P molar ratios of 1:1 or 1.5:1, and by adsorption onto newly formed Fe hydroxides exhibiting an Fe/P molar ratio of up to 11:1. All of these mechanisms efficiently reduced P solubility and are crucial in biosolids environmentally safe agronomic beneficial use for this waste product; however, each P phase formed may react differently in the amended soil, depending on soil properties. Thus, the proper P stabilization method would depend on the target soil. 相似文献
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Various non-invasive techniques for prenatal diagnosis have been under investigation. We evaluated the success of fetal sexing using a non-invasive technique for obtaining fetal cells, uterine cervix brushing, in combination with FISH. Thirty pregnant women who completed between 6 and 10 weeks of gestation and who were scheduled to undergo pregnancy termination were included in the study. A Pap smear cytobrush was inserted through the external os to a maximum depth of 2 cm and removed while rotating it a full turn. The material that was caught on the brush was spread on four microscope slides. Two-color FISH was used for fetal sexing. Following pregnancy termination, a placental sample was used for full karyotyping. In 29/30 cases FISH diagnosis was confirmed by chromosomal analysis. The only male case in which a Y chromosome was not seen was from a pregnancy of 6 weeks 6 days gestational age. One case was mosaic of 46,XY/47,XXY (25%). In most cases (7/13) the Y chromosome was already identified in the first analyzed slide. With the use of a cytobrush fetal cells can be easily obtained for the purpose of prenatal diagnosis of chromosomal disorders. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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This paper describes a multistage algorithm for efficient calculation of magnetic flux contours, for optimizing the design
of structural magnetic shielding. It is part II of the article presented in Pekar and Netzer (2006). The Environmentalist. The multi-stage algorithm enables albeit medium-power computer system to calculate the effect of shielding materials with
a given geometry, in a reasonable timeframe without compromising precision. The outcome results are a large number of electrical
utility models and the best cost-effective shielding materials and geometries for ELF magnetic flux reduction per Authority
regulations and requirements. This article reviews methods and principles for calculation of an extremely low frequency (50/60 Hz)
electromagnetic field originating from power utilities and power lines, for the purpose of constructing efficient magnetic
shielding. The paper points out difficulties in existing methods and proposes a new algorithm for analysis and construction
of magnetic shielding. 相似文献
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Summary The major objective of the design of safe crowded transmitting antenna sites is not only to determine a safe zone around each
individual antenna; rather, to establish safety areas at the antenna site itself, as well as, at the neighboring areas. The
requirement is to ascertain the safety regions by considering the following parameters at each Test Point (TP) (or area segment):
the contribution of N co-located radiating antennas to the total radiation incident at the TP, the radiation pattern of each antenna, the near/far
field region of each antenna, and most importantly, the different Permissible Exposure Limits (PELs) associated with each
operating frequency at the antenna site. Implementation of all the above-mentioned aspects in a suitable computer requires
resources that only expert knowledgeable organizations possess. The graphically aided tool presented in this paper facilitates
the calculation of a “safety zone” for RADHAZ around a crowded antenna site from the knowledge of the “safety ranges” which
correspond to the individual transmitting antennas comprising it. 相似文献