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541.
Outbreaks of paralytic shellfish poisoning (PSP) and dense blooms caused by Alexandrium species in Jinhae-Masan Bay, Korea have been nearly annual events for many years. However, excluding some Alexandrium species responsible for PSP, there are no critical reports on the morphology of Alexandrium species in this bay. To identify the Alexandrium species based on detailed morphological features, vegetative cells collected water samples and established by the incubation of resting cysts isolated from sediment trap samples were analyzed. Four species of Alexandrium were identified: Alexandrium affine, A. fundyense, A. catenella, and A. insuetum. Morphological features of these species were basically consistent with those outlined in previous studies. However, the ventral pore and the connecting pore on the sulcal plate, which have been accepted as diagnostic characteristics for the identification of A. fundyense and A. catenella, need to be reevaluated, indicating that useful morphological features for identifying these two species should be recommended to avoid confusion in the classification of species in genus Alexandrium.  相似文献   
542.
A simulation of suspended sediment movement relating to tidal and wave forcing during a winter monsoon in November 1983 in the Huanghai and East China Seas continental shelf is attempted by using the model describing the cohesive/non-cohesive sediment resuspension generated by interactions between currents and waves.model simulation showed that sediment concentration was increased by resuspension at shallow depths during the strong storm conditions due to high bottom stress interacted between currents and waves. This result is in general agreement with observations in horizontal distribution of suspended sediment distribution.At three current meter mooring positions off the southern Shandong Peninsula resuspension occurred only at a depth of 22m,nearest coastal position and at deeper parts at depths of 51 and 80m wave-current interaction effects were not significant. It has shown that the present model simulation demonstrated the capability of reproduction of suspended sediment movement under wintertime extreme event reasonably well.  相似文献   
543.
Often researchers position themselves in relation to race, age and gender, but the body is less often discussed as an actual 'instrument of research'. We aim to extend thinking on this point by reflecting on a project we conducted on migrant women and food in New Zealand. We present a vignette as an example of how we used our bodies as 'instruments of research' at a 'shared lunch' attended by new migrants from a range of different countries. At the lunch some combined on their plates spicy dishes such as kimch'i (fermented vegetables) and sweet dishes such as pavlova (a meringue dessert). For others this combination prompted feelings of disgust. We conclude that the body is a primary tool through which all interactions and emotions filter in accessing research subjects and their geographies.  相似文献   
544.
Sediment toxicity in silty marine harbor sediments is frequently dominated by ammonia or sulfide, leaving the adverse effects of persistent toxic substances unnoticed. To investigate the latter, we subjected interstitial water from three contaminated silty sediments to toxicity identification evaluation (TIE) phase I manipulations and tested for toxicity with four bioassays: the amphipod Corophium volutator (survival as an endpoint), the sea urchin Psammechinus miliaris (fertilization, embryo development) and the bacterium Vibrio fischeri (bioluminescence inhibition).The graduated pH manipulations identified the prominent toxicity of ammonia in the amphipod and sea urchin embryo tests, and also sulfide toxicity in the bacterium test. In two of the three samples tested with the amphipods, sea urchin embryos and bacteria, a small but significant reduction in interstitial water toxicity was achieved by removing persistent compounds through C(18) solid phase extraction. EDTA chelation resulted in a slight detoxification of the interstitial water for the amphipods and sea urchin embryos, but this was not related to any measured trace metals. Despite the presence of toxic levels of ammonia and sulfide in the harbor sediments, we established the adverse biological effects of persistent constituents by means of the TIE manipulations and in vivo interstitial water bioassays.  相似文献   
545.
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547.
Feasibility of electrokinetic (EK) process combined with Fenton-like reaction was investigated for the removal of phenanthrene in a two-dimensional cell. Sandy soil and bentonite were selected as a model soil and a filling material to inhibit the leak of electrolyte solution within the electrode reservoirs into the soil by hydraulic pressure difference, respectively. The effects of parameters including current, electroosmotic flow (EOF), electrolyte pH, and moisture content on the removal efficiency were examined under constant voltage.

At the end of operation for 21 days, the concentration of phenanthrene near the anode was lower than the other positions of soil specimen and increased gradually towards the cathode because hydrogen peroxide solution was supplied from anode to cathode region following the direction of EOF. The concentration of phenanthrene at the bottom soil was lower than that at the top soil. Because capillary attraction in the sandy soil with high porosity was too low to maintain appropriate moisture at the top of the cell, EOF moved through the bottom soil with higher moisture content. Overall removal efficiency at 140 V was 81.6%, which was higher than 68.9% at 100 V because total EOF increased by a factor of 1.5 upon increase of the voltage from 100 to 140 V. In addition, power consumptions at 100 and 140 V were 7.2 and 19.4 kWh, respectively.  相似文献   

548.
We present a digital elevation model (DEM) of King Edward VII Peninsula, Sulzberger Bay, West Antarctica, developed using 12 European Remote Sensing (ERS) synthetic aperture radar (SAR) scenes and 24 Ice, Cloud, and land Elevation Satellite (ICESat) laser altimetry profiles. We employ differential interferograms from the ERS tandem mission SAR scenes acquired in the austral fall of 1996, and four selected ICESat laser altimetry profiles acquired in the austral fall of 2004, as ground control points (GCPs) to construct an improved geocentric 60-m resolution DEM over the grounded ice region. We then extend the DEM to include two ice shelves using ICESat profiles via Kriging. Twenty additional ICESat profiles acquired in 2003-2004 are used to assess the accuracy of the DEM. After accounting for radar penetration depth and predicted surface changes, including effects due to ice mass balance, solid Earth tides, and glacial isostatic adjustment, in part to account for the eight-year data acquisition discrepancy, the resulting difference between the DEM and ICESat profiles is -0.57/spl plusmn/5.88 m. After removing the discrepancy between the DEM and ICESat profiles for a final combined DEM using a bicubic spline, the overall difference is 0.05/spl plusmn/1.35 m.  相似文献   
549.
In order to improve the efficiency of disaster reduction, the government of Taiwan has taken a number of initiatives in the development of disaster reduction technology since 1982, including the 1st, 2nd and 3rd 5-year plans for hazards prevention research, and the National Science and Technology Program for Hazards Mitigation (NAPHM). In this article, the contents and achievements of the 5-year plans and the NAPHM are briefly reviewed. On the one hand, the 5-year plans have produced meaningful research results; on the other hand, the NAPHM has provided a mechanism for integrating and translating the research results into technologies that can be implemented. The NAPHM was transformed in 2003 into the National Science and Technology Center for Disaster Reduction (NCDR) to further enhance the development and implementation of disaster technology. The mission and major future works of the NCDR are discussed.  相似文献   
550.
Aqueous foam, in combination with microorganisms and chemical additives, was tested for the reduction of the emissions of odorous compounds from swine manure. Ammonia and hydrogen sulfide were selected as test compounds. Aqueous foam decreased the ammonia and hydrogen sulfide emissions by about 33.2 and 66.2%, respectively, after application for 1,800 min. With the application of aqueous foam, amended with 1% of monocalcium phosphate or Yucca extracts, about 81.4 and 51.6%, respectively, of the ammonia emissions were suppressed over the same time period. However, the chemical additives were found to be ineffective in the suppression of hydrogen sulfide. Finally, the aqueous foam, containing microorganisms and the two chemical additives, attained about 88.3 and 70% ammonia and hydrogen sulfide emissions suppression, respectively. The data show that the aqueous foam was effective in the control ammonia and hydrogen sulfide emissions, and the suppression capacity can be markedly enhanced by the addition of appropriate microorganisms and chemical additives.  相似文献   
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