排序方式： 共有38条查询结果，搜索用时 15 毫秒
31.
Y. Ghafuria M. Yunesian R. Nabizadeh A. Mesdaghinia M. H. Dehghani M. Alimohammadi 《International Journal of Environmental Science and Technology》2018,15(9):1983-1990
Platinum-based cytotoxic drugs are complexes of Pt used in 50–70% of cancer patients. This study was performed during 2015, in two oncology wards of Qom hospitals in Iran. Sampling was carried out using effluent of the oncology wards for measurement of total Pt concentration. Analysis was performed by ICP–OES, and limit of detection was determined (LODs = 1 µg/L). During the sampling days, the total Pt concentration in the wastewater effluent oncology ward ranged from 5 to 762 µg/L at Shahid Beheshti Hospital and from 3 to 629 µg/L at Hazrat Masoumeh Hospital. According to the results from concentration of cytotoxic drugs, the predicted environmental concentrations (PECs) (ng/L) in wastewater treatment plant effluent and river for cisplatin, carboplatin and oxaliplatin were determined. Calculated RQhww showed that \(\sum {\text{RQ}}_{\text{hww}} = 1.19\). Thus, the total platinum compound drug could have potential toxicity effect on aquatic organisms. It was concluded that monitoring of cytotoxic drugs residue in hospital effluent must be considered because of their toxicity and impact on aquatic pollution. The results also revealed that PEC < 10 ng/L for all the platinum compound drugs and sum of the PEC calculation (\(\sum {\text{PEC}}_{{{\text{cis}},{\text{carbo}},{\text{oxali}}}}\)). 相似文献
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Only with satellites it is possible to cover the entire Earth densely with gravity field related measurements of uniform quality
within a short period of time. However, due to the altitude of the satellite orbits, the signals of individual local masses
are strongly damped. Based on the approach of Petrovskaya and Vershkov we determine the gravity gradient tensor directly from
the spherical harmonic coefficients of the recent EIGEN-GL04C combined model of the GRACE satellite mission. Satellite gradiometry
can be used as a complementary tool to gravity and geoid information in interpreting the general geophysical and geodynamical
features of the Earth. Due to the high altitude of the satellite, the effects of the topography and the internal masses of
the Earth are strongly damped. However, the gradiometer data, which are nothing else than the second order spatial derivatives
of the gravity potential, efficiently counteract signal attenuation at the low and medium frequencies.
In this article we review the procedure for estimating the gravity gradient components directly from spherical harmonics coefficients.
Then we apply this method as a case study for the interpretation of possible geophysical or geodynamical patterns in Iran.
We found strong correlations between the cross-components of the gravity gradient tensor and the components of the deflection
of vertical, and we show that this result agrees with theory. Also, strong correlations of the gravity anomaly, geoid model
and a digital elevation model were found with the diagonal elements of the gradient tensor. 相似文献
34.
Saeid Jamshidi Ramin Bozorgmehry Boozarjomehry Mahmoud Reza Pishvaie 《Advances in water resources》2009
In pore network modeling, the void space of a rock sample is represented at the microscopic scale by a network of pores connected by throats. Construction of a reasonable representation of the geometry and topology of the pore space will lead to a reliable prediction of the properties of porous media. Recently, the theory of multi-cellular growth (or L-systems) has been used as a flexible tool for generation of pore network models which do not require any special information such as 2D SEM or 3D pore space images. In general, the networks generated by this method are irregular pore network models which are inherently closer to the complicated nature of the porous media rather than regular lattice networks. In this approach, the construction process is controlled only by the production rules that govern the development process of the network. In this study, genetic algorithm has been used to obtain the optimum values of the uncertain parameters of these production rules to build an appropriate irregular lattice network capable of the prediction of both static and hydraulic information of the target porous medium. 相似文献
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R. Nabizadeh A. Mahvi G. Mardani M. Yunesian 《International Journal of Environmental Science and Technology》2005,1(4):325-333
A cross-sectional survey was conducted through Tehran city and a field study was conducted to prepare main and accessory drainage channels map. Three main drainage channels were identified for this research and some sampling stations were chosen. Three stations selected in south of Tehran. The reason for selecting these stations is that all urban surface runoff completelypass through these points and samples taken from these points are representative of all kinds of pollutants that transit from city surface. Another Three stations were selected in center and further three stations were selected at north of Tehran. Surface runoff flow in three main channels, from north to south of Tehran, converge at south of Rey city and finally end up to Ghom Salt lake. The stations were chosen at three trajectories, Sorkhe Hesar, Emad Avard, Kan. At each month two samples were prepared from nine different stations. After collection of samples with respect to standard methods, they were dissolved in nitric acid and then analyzed by atomic absorption device. The results show that the concentrations of pollutants increased from north to south. For instance, Zinc had most concentration with monthly average of 0.98 mg/l and Nickel had the lowest amount with 0.02 mg/l in southern stations. Average concentration of Zn, Pb, Cd, Cu and Ni were: 0.638, 0.097, 0.04 and 0.035 mg/l respectively. Total average concentrations of heavy metals at three main channels were of 0.177, 0.176 and 0.145 mg/l. Emad Avard was the most polluted channel. 相似文献
37.
Non-parametric trend analysis of the aridity index for three large arid and semi-arid basins in Iran 总被引：2，自引：1，他引：1
Hossien Ahani Mehrzad Kherad Mohammad Reza Kousari Lieke van Roosmalen Ramin Aryanfar Seyyed Mashaallah Hosseini 《Theoretical and Applied Climatology》2013,112(3-4):553-564
Currently, an important scientific challenge that researchers are facing is to gain a better understanding of climate change at the regional scale, which can be especially challenging in an area with low and highly variable precipitation amounts such as Iran. Trend analysis of the medium-term change using ground station observations of meteorological variables can enhance our knowledge of the dominant processes in an area and contribute to the analysis of future climate projections. Generally, studies focus on the long-term variability of temperature and precipitation and to a lesser extent on other important parameters such as moisture indices. In this study the recent 50-year trends (1955–2005) of precipitation (P), potential evapotranspiration (PET), and aridity index (AI) in monthly time scale were studied over 14 synoptic stations in three large Iran basins using the Mann–Kendall non-parametric test. Additionally, an analysis of the monthly, seasonal and annual trend of each parameter was performed. Results showed no significant trends in the monthly time series. However, PET showed significant, mostly decreasing trends, for the seasonal values, which resulted in a significant negative trend in annual PET at five stations. Significant negative trends in seasonal P values were only found at a number of stations in spring and summer and no station showed significant negative trends in annual P. Due to the varied positive and negative trends in annual P and to a lesser extent PET, almost as many stations with negative as positive trends in annual AI were found, indicating that both drying and wetting trends occurred in Iran. Overall, the northern part of the study area showed an increasing trend in annual AI which meant that the region became wetter, while the south showed decreasing trends in AI. 相似文献
38.
A. A. Babaei A. H. Mahvi R. Nabizadeh A. Mesdaghiniai Z. Nazari E. Ahmadpour 《International Journal of Environmental Science and Technology》2014,11(2):477-482
The important Iranian Karun River has never been investigated for the presence of potentially endocrine-disrupting chemicals, nonylphenol (NP). In this study, concentrations of NP were measured in water from Karun River and five wastewater discharge points into this river, collected during April to July 2010. The analytes were extracted by solid-phase extraction, and quantitative analyses were performed by HPLC–FLD. NP was detected in water and wastewater samples with 0.17–1.83 and 15.27–21.79 μg/L, respectively. The results showed that the NP content of aqueous phase of all wastewater samples higher than particulate phase, which were detected in the aqueous and particulate phases with mean concentrations of 12.8 ± 2.4 and 5.2 ± 1.2 μg/L, respectively. These data suggest that the NP levels in Karun river water are likely attributable to untreated municipal wastewaters discharged directly into the river. To our knowledge; this is the first study to evaluate NP concentrations in water and wastewater in Iran. 相似文献