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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.
Uddin, A.S.M. Iftekhar,Yaqoob, Usman,Phan, Duy-Thach,Chung, Gwiy-Sang Elsevier 2016 Sensors and actuators. B, Chemical Vol.222 No.-
<P><B>Abstract</B></P> <P>The paper presents a novel flexible acetylene gas sensor consisting of Ag-loaded vertical ZnO nanorods (NRs) supported by a polyimide/polytetrafluoroethylene substrate. The fabricated sensor exhibits a high response magnitude of 27.2 (1000ppm), short response/recovery time of 62/39s, and broad detection range from 3 to 1000ppm at a low operating temperature of 200°C. The enhancement of sensing performance was mainly attributed to the large effective surface area, small grain size, ordered arrays of ZnO NRs, and the successful immobilization of tiny sized Ag nanoparticles. At optimum conditions (8s Ag-loaded ZnO NRs at 200°C), the sensor showed a negligible response degradation of ∼2.1% at a curvature angle of 90°, and ∼8% for 5×10<SUP>4</SUP> bending/relaxing cycles. The outstanding flexibility of the as-fabricated sensor ensured stable sensing performances to extreme bending stress, indicating the possibility of fabricating highly efficient and practical flexible C<SUB>2</SUB>H<SUB>2</SUB> gas sensors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A flexible acetylene sensor is demonstrated for the first time. </LI> <LI> Ag-loaded vertical ZnO nanorods were synthesized by hydrothermal-RF magnetron sputtering method. </LI> <LI> 8s Ag-loaded sensor showed best sensing performance at 200°C. </LI> <LI> The fabricated sensor showed excellent mechanical stability up to a bending angle of 90°. </LI> <LI> No significant response degradation was observed up to 5×10<SUP>4</SUP> bending/relaxing cycles. </LI> </UL> </P>
Uddin, A.S.M. Iftekhar,Yaqoob, Usman,Hassan, Kamrul,Chung, Gwiy-Sang Elsevier 2016 International journal of hydrogen energy Vol.41 No.34
<P><B>Abstract</B></P> <P>In the current contribution, Pd@Pt core-shell nanocrystals-based resistivity-type sensor has been realized with the aim of implementing a fast-response hydrogen (H<SUB>2</SUB>) sensor and investigating the effect of shell thickness on sensing properties. Pd@Pt core-shell nanocrystals as colloids were synthesized via a chemical route and were then carefully assembled on a SiO<SUB>2</SUB>/Si substrate using the self-assembly monolayer (SAM) technique. Three different Pd@Pt core-shell nanocrystals with varied Pt shell thicknesses were synthesized for the SAM process. The short diffusion length of Pd@Pt due to the thin Pt shell layer and the monolayer distribution of the Pd@Pt core-shell preferentially accelerated the adsorption–desorption of the H<SUB>2</SUB> molecules on the sensing interface, resulting in a very quick response to H<SUB>2</SUB> gas. At an optimum operating temperature of 150 °C, the sensor showed a fast-response time of 6 s, a maximum response of 3.6% to 1 vol.% gas concentration, and a broad detection range of 0.001–4 vol.% H<SUB>2</SUB> concentrations. The aforementioned outcomes of the as-fabricated sensor demonstrate the possibility of implementing an efficient H<SUB>2</SUB> sensor for safety applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Synthesis of Pd@Pt core-shell nanocrystals in a facile and rapid chemical route. </LI> <LI> Deposition of Pd@Pt core-shell through self-assembly monolayer technique. </LI> <LI> Role of monolayer distribution in fast H<SUB>2</SUB> sensing. </LI> <LI> Effect of Pt shell thickness in adsorption–desorption of the H<SUB>2</SUB> molecules. </LI> </UL> </P>
Awad, Y.M.,Lee, S.E.,Ahmed, M.B.M.,Vu, N.T.,Farooq, M.,Kim, I.S.,Kim, H.S.,Vithanage, M.,Usman, A.R.A.,Al-Wabel, M.,Meers, E.,Kwon, E.E.,Ok, Y.S. Butterworth-Heinemann, Ltd 2017 Journal of cleaner production Vol.156 No.-
A hydroponics system developed using a nutrient film technique was used to evaluate the effectiveness of rice husk biochar (RB) alone or in combination with perlite (PL) as substrates for increasing the growth of leafy vegetables compared with that of PL. Seedlings of cabbage, dill, mallow, red lettuce, and tatsoi were grown hydroponically in PL, RB, and PL + RB (1:1 ratio of PL to RB, v/v) substrates for a 30-d under optimal environmental conditions in a greenhouse. Shoot length and fresh/dry masses of cabbage, dill, and red lettuce plants grown in RB substrate were decreased by 49% on average compared to those plants grown in PL substrate. In contrast, PL + RB substrate led to approximately 2-fold increases in shoot length, number of leaves, and fresh/dry masses of leafy vegetable plants compared with those grown in PL substrate. Foliar nutritional composition (Ca, Mg, K, Na, Mn, Fe, and Zn) and nitrogen status (SPAD index) of plants grown in PL + RB and PL substrates suggested the presence of optimal growth conditions for ensuring optimum yield with high quality. In addition, RB substrate contributed to respective increases of 1.2-3.5-fold in leaf K, Mg, Mn, and Zn contents in most vegetable plants compared with those grown in PL substrate. The RB alone or in combination with PL substrates decreased algal growth in the nutrient solutions as confirmed by scanning electron micrographs of microalgae on the RB surface. The results also indicated that use of PL + RB hydroponic substrate could be an alternative and effective technology for the better management of unwanted algal growth in nutrient solutions and high production of leafy vegetables.
Usman, A.R.A.,Almaroai, Yaser.A.,Ahmad, M.,Vithanage, M.,Ok, Y.S. Elsevier Scientific Pub. Co 2013 Journal of hazardous materials Vol.262 No.-
Chelating agents added to contaminated soils may increase solubility and phytoextraction efficiency of soil metals. However, they can create negative effects on soil biological quality. A 90-day incubation experiment was conducted to evaluate mixed effects of chelating agents and poultry manure on changes in available Cd, Pb and As, CO<SUB>2</SUB>-C efflux, microbial biomass C, dissolved organic C (DOC), and N mineralization in metal-polluted agricultural soil. Application of poultry manure resulted in a considerable increase in soil pH, DOC, CO<SUB>2</SUB>-C efflux, net N mineralization, net N nitrification, and microbial biomass C compared to those in unmanured soil. Availability of arsenic increased twice in manure amended soil due to changes in pH and DOC. However, adding poultry manure did not affect the concentrations of available Pb and Cd compared to those in control soil. Chelating agents increased CO<SUB>2</SUB>-C efflux, DOC, and metal availability but decreased microbial biomass C and net N mineralization. Maximum decrease in microbial biomass C, net N mineralization, and net N nitrification, was observed in EDTA applied soil possibly due to high metal availability to soil microorganisms. Overall results revealed that the application of synthetic chelators in combination with poultry manure enhances available As and demonstrates better environment for soil biota.
Fine structure of the isoscalar giant quadrupole resonance inSi28andAl27
Usman, I. T.,Buthelezi, Z.,Carter, J.,Cooper, G. R. J.,Fearick, R. W.,Fö,rtsch, S. V.,Fujita, H.,Fujita, Y.,von Neumann-Cosel, P.,Neveling, R.,Papakonstantinou, P.,Pysmenetska, I.,Richter, A.,Roth American Physical Society 2016 Physical Review C Vol.94 No.2
<P>The isoscalar giant quadrupole resonance in Si-28 and Al-27 has been investigated with high-energy-resolution proton inelastic scattering at E-p = 200 MeV and at scattering angles close to the maximum of Delta L = 2 angular distributions with the K600 magnetic spectrometer of iThemba LABS, South Africa. Characteristic scales are extracted from the observed fine structure with a wavelet analysis and compared for Si-28 with random-phase approximation and second random phase approximation calculations with an interaction derived from the Argonne V18 potential by a unitary transformation. A recent extension of the method to deformed nuclei provides the best description of the data, suggesting the significance of Landau damping.</P>
Hypocholesterolemic Effect of Indigenous Dadih Lactic Acid Bacteria by Deconjugation of Bile Salts
Pato, Usman,Surono, Ingrid S.,Koesnandar, Koesnandar,Hosono, Akiyoshi Asian Australasian Association of Animal Productio 2004 Animal Bioscience Vol.17 No.12
Administration of milk and fermented milks produced from indigenous dadih lactic acid bacteria on serum lipids and bile acids, fecal bile acids and microflora was estimated in hypercholesterolemic rats. Anaerobic lactic acid bacteria decreased and coliforms increased in the feces of the control group; however, the number of fecal lactic acid bacteria remained unchanged when rats were administered milk and fermented milks. Only fermented milk made from Lc. lactis subsp. lactis IS-10285 significantly reduced serum total cholesterol, LDL cholesterol and total bile acids. Milk and fermented milks did not influence the HDL cholesterol. Triglyceride and phospholipid levels were significantly lower in the rats fed fermented milk of Lc. lactis subsp. lactis IS-10285 than rats fed milk and fermented milk of Lc. lactis subsp. lactis IS-29862, but not significantly different from the control group. Hypocholesterolemic effect of Lc. lactis subsp. lactis IS-10285 was attributed to its ability to suppress the reabsorption of bile acids into the enterohepatic circulation and to enhance the excretion of bile acids in feces of hypercholesterolemic rats.