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( S. Lee ),( A. R. A. Usman ),( S. A. M. Abd El-azeem ),( Y. M. Awad ),( M. Kim ),( K. Ham ),( J. Lim ),( J. E. Yang ),( S. S. Lee ),( Y. S. Ok ) 강원대학교 농업생명과학연구원(구 농업과학연구소) 2011 강원 농업생명환경연구 Vol.23 No.1
Contamination of the soil with Cr, Cu and As has become a worldwide environmental problem as a consequence of the use of chromated copper, arsenate (CCA) treated wood. This study was conducted (i) to determine the total concentrations of Cr, Cu and As in soil samples collected from contaminated sites, (ii) to identify native plant species grown on contaminated sites for phytoremediation, and (iii) to estimate the risk of adverse effects on human health. Wood and soil samples as well as four native plant species (Viola mandshurica, Cyndon dactylon, Setaria viridis and Acalypha australis) were collected from three contaminated sites with Cr, Cu and As in Gangwon Province, Korea. Our results found that the metal concentrations of these soil sampling sites were higher than their background levels of 45.32, 30.22 and 7.0 mg/kg for Cr, Cu and As, respectively, indicating the adverse effects on human health. None of the four plant species showed metal concentrations>1000 mg/kg in their shoots and were not served as hyperaccumulators. Nevertheless, the screened plant species might be suitable for phytoextraction or phytostabilization. We conclude that the development of environmentally friendly technology for remediating heavy metal contaminated soils is needed to ensure human safety or agricultural purposes.
Awad, Y. M.,Kim, S. C.,Abd El-Azeem, S. A.,Kim, K. H.,Kim, K. R.,Kim, K.,Jeon, C.,Lee, S. S.,Ok, Y. S. Springer Science + Business Media 2014 Environmental earth sciences Vol.71 No.3
Antibiotics have been commonly used to prevent animal diseases and promote livestock productivity. However, its release into the surrounding environments leads to ecological disturbance and risks to human health. This study was conducted to monitor the occurrence and seasonal variations of antibiotics in water, sediment, and soil close to a swine manure composting facility, Korea. Various types of antibiotics such as tetracyclines (TCs) including tetracycline, chlortetracycline, and oxytetracycline, and sulfonamides (SAs) including sulfamethazine, sulfamethoxazole, and sulfathiazole were measured by the high-performance liquid chromatography-tandem mass spectrometry via a solid-phase extraction. In the results it was identified that the variations of measured antibiotics' concentrations in water, sediment, and soil are depending on the season. The observed concentration levels of TCs were higher in winter than in summer season, indicating that the low temperature is a parameter attributing to interruption of its degradation in water, sediment, and soil. The concentration levels of SAs were significantly higher than those of TCs and in general, all measured antibiotics' concentrations were also in general higher in Korea when compared to those in other countries. The long-term monitoring of antibiotics' residues in aquatic and terrestrial environments is necessary.
Studying the operation of MOSFET RC-phase shift oscillator under different environmental conditions
Ibrahim Reiham O.,Abd El-Azeem S.M.,El-Ghanam S.M.,Soliman F.A.S. 한국원자력학회 2020 Nuclear Engineering and Technology Vol.52 No.8
The present work was mainly concerned with studying the operation of RC-phase shift oscillator based on MOSFET type 2N6660 under the influence of different temperature levels ranging from room temperature (25 C) up-to135 C and gamma-irradiation up-to 3.5 kGy. In this concern, both the static (IeV) characteristic curves of MOSFET devices and the output signal of the proposed oscillator were recorded under ascending levels of both temperature and gamma-irradiation. From which, it is clearly shown that the drain current was decreased from 0.22 A, measured at 25 C, down to 0.163 A, at 135 C. On the other hand, its value was increased up-to 0.49 A, whenever the device was exposed to gamma-rays dose of 3.5 kGy. Considering RC-phase shift oscillator, the oscillation frequency and output pk-pk voltage were decreased whenever MOSFET device exposed to gamma radiation by ratio 54.9 and 91%, respectively. While, whenever MOSFET device exposed to temperature the previously mentioned parameters were shown to be decreased by ratio 2.07 and 46.2%.