排序方式: 共有10条查询结果,搜索用时 343 毫秒
1
1.
2.
Meththika Vithanage Indika Herath Yaser A. Almaroai Anushka Upamali Rajapaksha Longbin Huang Jwa-Kyung Sung Sang Soo Lee Yong Sik Ok 《Environmental geochemistry and health》2017,39(6):1409-1420
This study examined the effects of carbon nanotube and biochar on the bioavailability of Pb, Cu and Sb in the shooting range soils for developing low-cost remediation technology. Commercially available multi-walled carbon nanotube (MWCNT) and biochar pyrolyzed from soybean stover at 300 °C (BC) at 0.5, 1 and 2.5% (w w?1) were used to remediate the contaminated soil in an incubation experiment. Both DTPA (bioavailable) and TCLP (leaching) extraction procedures were used to compare the metal/loid availability and leaching by the amendments in soil. The addition of BC was more effective in immobilizing mobile Pb and Cu in the soil than that in MWCNT. The BC reduced the concentrations of Pb and Cu in the soil by 17.6 and 16.2%, respectively. However, both MWCNTs and BC increased Sb bioavailability by 1.4-fold and 1.6-fold, respectively, in DTPA extraction, compared to the control. The toxicity characteristic leaching procedure (TCLP) test showed that the leachability of Pb in the soil amended with 2.5% MWCNT was 1.3-fold higher than that the unamended soil, whereas the BC at 2.5% decreased the TCLP-extractable Pb by 19.2%. Precipitation and adsorption via electrostatic and π–π electron donor–acceptor interactions were postulated to be involved in the interactions of Pb and Cu with surfaces of the BC in the amended soils, whereas ion exchange mechanisms might be involved in the immobilization of Cu in the MWCNT-amended soils. The application of BC derived from soybean stover can be a low-cost technology for simultaneously immobilizing bioavailable Pb and Cu in the shooting range soils; however, neither of amendments was effective in Sb immobilization. 相似文献
3.
We report a case of monochorionic diamniotic twin gestation confirmed by ultrasound visualization of the thin intertwin-dividing membrane at 32 weeks' gestation. Ultrasound at 36 weeks failed to demonstrate the thin dividing membrane. The pregnancy ended a few days later with spontaneous vaginal delivery of the first twin. The second twin was in transverse lie with no membranes that could be felt around. Severe fetal heart rate deceleration developed, prompting delivery by emergency caesarean section. Cord entanglement was noted at the time of delivery, which resulted in severe perinatal morbidity of the second twin. The antepartum rupture of the dividing membrane must have happened some time between 32 and 36 weeks. The etiology for this intrauterine disruption is unknown. A review of the literature about the antepartum rupture of the intertwin-dividing membrane is described, along with its possible causes and complications. In addition, we discuss possible causes of incorrect amnionicity determination, and thus how to minimize these pitfalls. We conclude that antepartum disruption of the intertwin-dividing membrane is more common than previously thought. Moreover, prenatal ultrasonographic visualization of a dividing membrane in a diamniotic twin pregnancy does not rule out future change in this environment to a monoamniotic one, with all its perinatal morbidity and mortality complications, which result mainly from cord entanglement. This suggests a modification in the method and frequency of the prenatal fetal well-being follow-up, as well as the time and mode of delivery. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
4.
Ghaffari Hamid Reza Farshidi Hossein Alipour Vali Dindarloo Kavoos Azad Mehdi Hassani Jamalidoust Marzieh Madani Abdolhossein Aghamolaei Teamour Hashemi Yaser Fazlzadeh Mehdi Fakhri Yadolah 《Environmental science and pollution research international》2022,29(57):85612-85618
Environmental Science and Pollution Research - There is ambiguity about the airborne transmission of the SARS-CoV-2. While a distance of 6 feet is considered a safe physical distance, new findings... 相似文献
5.
Al-Momani IF Momani KA Jaradat QM Massadeh AM Yousef YA Alomary AA 《Environmental monitoring and assessment》2008,136(1-3):209-218
Wet and dry deposition samples were collected in the capital of Jordan, Amman. Concentrations of Al, Ba, Bi, Cd, Co, Cr, Cu,
Mn, Mo, Ni, Pb, Sb, V, Zn, Fe, Sr, Mg2+, Ca2+, Na+, K+, Cl−, NO3
− and SO4
2−, along with pH were determined in collected samples. Mean trace metal concentrations were similar or less than those reported
for other urban regions worldwide, while concentrations of Ca2+ and SO4
2− were among the highest. High Ca2+ concentrations were attributed to the calcareous nature of the local soil and to the influence of the Saharan dust. However,
high SO4
2− concentrations were attributed to the influence of both anthropogenic and natural sources. Except for Cl−, NO3
−, SO4
2− and Cu, monthly dry deposition fluxes of all measured species were higher than wet deposition fluxes. The annual wet deposition
fluxes of trace metals were much lower than those reported for other urban areas worldwide. 相似文献
6.
Vithanage Meththika Herath Indika Almaroai Yaser A. Rajapaksha Anushka Upamali Huang Longbin Sung Jwa-Kyung Lee Sang Soo Ok Yong Sik 《Environmental geochemistry and health》2018,40(1):565-565
Environmental Geochemistry and Health - Unfortunately, in the original publication of the article, Prof. Yong Sik Ok’s affiliation was incorrectly published. The author’s affiliation is... 相似文献
7.
The development of synthetic biodegradable polymers using solvent free polymerization has a unique potential to be used as sustainable polymers in biomedical applications. The aim of this work was to synthesize and characterize a sustainable class of poly(lactic acid) (PLA) under different operating conditions via direct polycondensation of lactic acid (LA). Several parameters were tested including the absence of solvents and catalysts on the polymerization, in addition to polymerization temperature and time. Polymerization conditions were evaluated using response surface method (RSM) to optimize the impact of temperature, time, and catalyst. Results showed that molecular weight (Mw) of PLA increased with increasing polymerization time. Highest Mw of 28.4 kD with relatively a broad polydispersity 1.9 was achieved at polymerization temperature 170?°C at 24 h in the free solvent polymerization. This led to a relevant inherent viscosity of 0.37 dl/g. FTIR spectra exhibited a disappearance of the characteristic peak of the hydroxyl group in LA at 3482 cm?1 by increasing the intensity of carbonyl group. The 1H nuclear magnetic resonance (NMR) exhibited the main chain at 5.22 ppm and the signal of methyl proton at 1.61 ppm as well as a signal at 4.33 and 1.5 assigned to the methane proton next to the terminal hydroxyl group and carboxyl group respectively. Meanwhile, the PLA synthesized with a catalyst [Sn(Oct)2] in a free solvent demonstrated comparatively high thermal transition properties of glass transition, melting, and crystallinity temperatures of 48, 106, and 158?°C, respectively. These results are of significant interest to further expand the use of PLA in biomedical applications. 相似文献
8.
Natural and synthesised iron-rich amendments for As and Pb immobilisation in agricultural soil 总被引:1,自引:0,他引:1
Yaser A. Almaroai Meththika Vithanage Anushka Upamali Rajapaksha Sang Soo Lee Xiaomin Dou Young Han Lee 《Chemistry and Ecology》2014,30(3):267-279
The immobilisation of heavy metals in contaminated soils is a promising alternative to conventional remediation techniques. Very few studies have focused on the use of iron-rich nanomaterials and natural materials for the adsorption of toxic metals in soils. Synthesised iron-rich nanomaterials (Fe and Zr–Fe oxides) and natural iron-rich materials (natural red earth; NRE) were used to immobilise As and Pb in contaminated agricultural soil. Total concentrations of As and Pb in the initial soil (as control) were 170.76 and 1945.11 mg kg?1, respectively. Amendments were applied into the soil at 1, 2.5 and 5% (w/w) in triplicate and incubated for 150 days. Except for the NRE-amended soil, soil pH decreased from 5.6 to 4.9 with increasing application rates of Fe and Zr–Fe oxides. With addition of Fe and Zr–Fe oxides at 5%, the ammonium acetate (NHO4Ac)-extractable Pb was greatly decreased by 83 and 65% compared with NRE addition (43%). All subjected amendments also led to a decrease in NHO4Ac-extractable As in the soils, indicating the high capacity of As immobilisation. Soil amended with NRE showed a lower ratio of cy19:0 to 18:1ω7c, indicating decreased microbial stress. The toxicity characteristic leaching procedure produced results similar to the NHO4Ac extraction for As and Pb. The NRE addition is recommended for immobilising heavy metals and maintaining biological soil properties. 相似文献
9.
Yaser Abunnasr Elisabeth M. Hamin Elizabeth Brabec 《Journal of Environmental Planning and Management》2015,58(1):135-155
There is a pressing need for municipalities and regions to create urban form suited to current as well as future climates, but adaptation planning uptake has been slow. This is particularly unfortunate because patterns of urban form interact with climate change in ways that can reduce, or intensify, the impact of overall global change. Uncertainty regarding the timing and magnitude of climate change is a significant barrier to implementing adaptation planning. Focusing on implementation of adaptation and phasing of policy reduces this barrier. It removes time as a decision marker, instead arguing for an initial comprehensive plan to prevent maladaptive policy choices, implemented incrementally after testing the micro-climate outcomes of previous interventions. Policies begin with no-regrets decisions that reduce the long-term need for more intensive adaptive actions and generate immediate policy benefits, while gradually enabling transformative infrastructure and design responses to increased climate impacts. Global and local indicators assume a larger role in the process, to evaluate when tipping points are in sight. We use case studies from two exemplary municipal plans to demonstrate this method's usefulness. While framed for urban planning, the approach is applicable to natural resource managers and others who must plan with uncertainty. 相似文献
10.
Al Mussa Ugak Mohd Mohamad Nurul Elyani Rajin Mariani Lamaming Junidah Saalah Sariah Yaser Abu Zahrim 《Journal of Material Cycles and Waste Management》2023,25(2):899-909
Journal of Material Cycles and Waste Management - Composting is a sustainable solution on campus for waste management as it is essential for achieving the ideal circular economy. This study aims to... 相似文献
1