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51.
Sediments along the Israeli coast were examined to determine the effects of large scale dumping of sewage on trace metal contents. The Tel Aviv-Yafo sewage pipeline outlet is the largest point source of sewage effluent along the coast.Significant quantities of trace metals—Ag, Co, Cr, Cu, Hg, Ni, Pb and Zn—were found in sediments extending to a distance as far as 400 m from the sewage pipeline outlet. Beyond this point, sufficient dilution occurs to limit contamination by sewage to relatively low levels at present. In the contaminated area, there are seasonable variations with maximum trace metal concentrations occurring in the summer. The upper layers of the cores contain a greater trace metal burden than do the lower. 相似文献
52.
Martin Piringer Sylvain Joffre Alexander Baklanov Andreas Christen Marco Deserti Koen De Ridder Stefan Emeis Patrice Mestayer Maria Tombrou Douglas Middleton Kathrin Baumann-Stanzer Aggeliki Dandou Ari Karppinen Jerzy Burzynski 《Boundary-Layer Meteorology》2007,124(1):3-24
The specific problems of determining and simulating the surface energy balance (SEB) and the mixing height (MH) over urban
areas are examined. The SEB and MH are critical components of algorithms and numerical models for the urban boundary layer,
though the constituent parts of the SEB and the MH are not routinely measured by national weather services. Parameterisations
are thus needed in applications. In this investigation, several recently developed algorithms and models for estimating the
SEB and MH were applied to new datasets and assessed. Results are discussed in terms of the need for spatial resolution and
the parameters needed to describe the urban atmosphere. Limitations of models are identified and recommendations for further
development and observations are given. Having identified gaps in knowledge, key findings from new urban experiments and numerical
modelling for the SEB and MH are given. The diurnal cycle for the SEB is significantly different from rural conditions—urban
heat storage is needed in urban parameterisations. The urban MH is increased over the rural MH, as shown by several numerical
schemes and careful sodar analyses. This work has been carried out within the COST-715 Action “Meteorology applied to urban
air pollution problems (1998–2004). COST 715 reached a consensus proposing representatively sited measurements of meteorological
parameters and turbulent fluxes above roof-tops, and recognised that such data are needed to improve numerical models of the
urban surface processes. 相似文献
53.
The lidar ratios at 500 and 1020 nm were derived from POM 01L sun-sky scanning photometer measurements taken at Belsk Geophysical
Observatory (long. 20°47′, lat. 51°50′) in the period from 2002 to 2006. The most frequently occurring lidar ratio values
for the study period are 50 sr and 30 sr at 500 nm and 1020 nm, respectively. Calculations of lidar ratios for summer and
winter seasons have been made as well. Back trajectory analysis was also performed to final aerosol source of origin. 相似文献
54.
Reliability with respect to settlement limit-states of shallow foundations on linearly-deformable subsoil 总被引:1,自引:0,他引:1
A step by step procedure for applying the response surface and SORM methods in estimating the reliability index associated with exceeding a certain allowable settlement level by a shallow foundation is presented in this paper. Two random variables, the Young modulus and Poisson's ratio, of lognormal and beta distribution respectively, in a single soil layer are taken into account. A linearly-deformable model of soil is assumed which is most frequently used in engineering practice when the serviceability limit state is considered. The main problem encountered in using the response surface methodology was the existence of false design points that prevented coordinate calculations of the real ones. Two procedures were employed. The first one consisted of widening the area covered by the response surface (polynomial of the second degree) with an additional “oedometric” term. Inserting the oedometric term improves the quality of the fitting and enables one to extend the range of approximation. The latter added a barrier to prevent the procedure from moving into the false design point region. Moreover, the paper presents the effect of random variation of the Young modulus E and Poisson's ratio ν as well as their mutual correlation, on the reliability index associated with exceeding the assumed level of a shallow foundation settlement. 相似文献
55.
Assessment of soils pollution extent in surroundings of ironworks based on magnetic analysis 总被引:1,自引:0,他引:1
This paper reports on magnetic and magnetomineralogical studies of soils influenced by ironworks activity. Researches were
conducted in five areas, of which Ostrowiec Świętokrzyski ironworks area is described in detail. A map of magnetic susceptibility
was created based on field measurements and samples taken from soil profile were analyzed in laboratory. Measurements of magnetic
susceptibility in two frequency ranges, anhysteretic remanent magnetization, isothermal remanent magnetization thermomagnetic
and geochemical analysis were carried out. SEM was used to identify ferromagnetic fractions. As a result the horizontal and
vertical extent of heavy metals pollution was established. 相似文献
56.
Karolina Kośmińska Jarosław Majka Stanisław Mazur Michael Krumbholz Iwona Klonowska Maciej Manecki Jerzy Czerny Maciej Dwornik 《地学学报》2014,26(5):377-386
Recent fieldwork in Nordenskiöld Land, Svalbard's Southwestern Basement Province, has established the presence of high‐pressure (HP) lithologies. They are strongly retrogressed blueschists consisting mainly of garnet and Ca‐amphibole with remnants of ferroglaucophane and phengite. The pressure–temperature (P–T) conditions were estimated using phase equilibrium modelling in the NCKFMMnASHTO system. P–T estimates based on the garnet, phengite and ferroglaucophane compositional isopleths and modelled paragenetic assemblage indicate peak metamorphism at 470–490 °C and 14–18 kbar. These data fall close to the 7–8 °C km?1 geotherm, which is similar to that from Motalafjella, the only previously known occurrence of blueschists in Svalbard's Caledonides. The newly discovered blueschists could have formed during the early stage of the Caledonian Orogeny and may represent a vestige of missing marginal basins of the western Iapetus developed at the onset of subduction. The likely counterpart to Svalbard's blueschists is the ophiolitic sequence in the Pearya Terrane of northern Ellesmere Island. 相似文献
57.
Janusz W. Krzyścin Piotr S. Sobolewski Janusz Jarosławski Jerzy Podgórski Bonawentura Rajewska-Więch 《Acta Geophysica》2011,59(1):155-182
Measurements of erythemal irradiance have been carried out continuously at Belsk since May 1975. We present a homogenization
procedure of the UV time series for the period of 1976–2008. Long-term oscillations discovered in the homogenized data set
agree with those extracted from the reconstructed UV data for all-sky and clear-sky conditions. The UV climatology was established
and the UV variability was determined. Positive UV trends were found for the period of 1976-2008 in the annual mean (5.6±0.9%
per decade), in the seasonal mean for the warm subperiod of the year (April–October, 5.5±1.0% per decade), and in monthly
means (∼2–9% per decade). A satisfactory agreement between the trend extracted from the homogenized ground-based data and
that found in satellite UV data for Belsk (1979–2008) supports the reliability of satellite trend analyses over wider areas
during snowless periods. 相似文献
58.
59.
Jerzy Rokicki 《Polar Science》2009,3(3):197-201
Anisakid nematodes are common in Antarctic, sub-Antarctic, and Arctic areas. Current distributional knowledge of anisakids in the polar regions is reviewed. Climatic variables influence the occurrence and abundance of anisakids, directly influencing their free-living larval stages and also indirectly influencing their predominantly invertebrate (but also vertebrate) hosts. As these parasites can also be pathogenic for humans, the paucity of information available is a source of additional hazard. As fish are a major human dietary component in Arctic and Antarctic areas, and are often eaten without heat processing, a high risk of infection by anisakid larvae might be expected. The present level of knowledge, particularly relating to anisakid larval stages present in fishes, is far from satisfactory. Preliminary molecular studies have revealed the presence of species complexes. Contemporary climate warming is modifying the marine environment and may result in an extension of time during which anisakid eggs can persist and hatch, and of the time period during which newly hatched larvae remain viable. As a result there may be an increase in the extent of anisakid distribution. Continued warming will modify the composition of the parasitic nematode fauna of marine animals, due to changes in feeding habits, as the warming of the sea and any localised reduction in salinity (from freshwater runoff) can be expected to bring about changes in the species composition of pelagic and benthic invertebrates. 相似文献
60.
Jerzy Sobotka 《Acta Geophysica》2009,57(2):247-256
The results of experimental studies of the propagation of longitudinal waves in saturated rock samples in which there is a
flow of electric charges are presented. It is shown that the electric field affects elastic parameters in heterophase media
by changing their dynamic characteristics. The aim of the study of the effect of electric field on the propagation of elastic
waves in saturated porous media was to determine the optimum conditions for this effect, and to construct a set of effective
parameters which could be used to increase the effectiveness of seismoacoustic prospecting methods, particularly acoustic
logging, and be helpful for developing new methods of increasing the effectiveness of oil extraction from productive wells. 相似文献