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Yoonaiwong W.,Ubon Ratchathani UniversityUbon Ratchathani | Kaewsarn P.,Ubon Ratchathani UniversityUbon Ratchathani | Reanprayoon P.,Surindra Rajabhat University
Sustainable Environment Research | Year: 2011

Biosorption of Pb(II) and Cd(II) ions by non-living macrophytes, Utricularia aurea has been investigated as a function of initial pH, contact time and metal concentrations. Adsorption kinetic and equilibrium tests were carried out in flasks under batch operations. The adsorption data obtained under optimum condition were evaluated by Freundlich and Langmuir isotherm. The biosorption kinetic results have shown that Pb(II) and Cd(II) ions removal rate was at its maximum at the beginning of the process. The equilibrium state was achieved after 30 min for lead and 90 min for cadmium. When experiments were performed with different desorbents the results indicated that 0.1 M HCl was an efficient desorbent for recovery of metal ions from biomass. In addition, Fourier transform infrared spectroscopy (FTIR) spectroscopy was done to identify the chemical functional group present on the biomass. The surface structure of biomass was analyzed by scanning electron microscopy (SEM). The biosorption mechanism of biosorbent was also evaluated by FTIR and SEM. © 2011, Chinese Institute of Environmental Engineering. All rights reserved. Source

Phuengphai P.,Surindra Rajabhat University | Phuengphai P.,Khon Kaen University | Phuengphai P.,Leiden University | Youngme S.,Khon Kaen University | And 3 more authors.
Inorganic Chemistry Communications | Year: 2012

A new porous coordination polymer, i.e. the two-dimensional layered network {[Cu 3(4,4′-bpy) 3(μ-OOCH) 4(H 2O) 2](BF 4) 2(H 2O) 6} n has been synthesized from Cu(BF 4) 26H 2O, 4,4′-bpy and with formate as co-ligand. Single-crystal X-ray diffraction analysis reveals a (4,4) 2D coordination network exhibiting voids that contain the counter-ions and water guest molecules. In addition, the title compound is further stabilized by hydrogen bonds and anion-π interactions to form an intricate supramolecular framework. The removal and reintroduction of guest water molecules has been explored to better understand the dynamic structural transformation. The coordination compound shows weak catalytic activity in the cyanosilylation of aldehydes. © 2012 Elsevier B.V. All rights reserved. Source

Phuengphai P.,Khon Kaen University | Phuengphai P.,Surindra Rajabhat University | Phuengphai P.,Leiden University | Youngme S.,Khon Kaen University | And 4 more authors.
Polyhedron | Year: 2012

Different combinations of three building blocks, namely the coordination moiety [copper(II)-4,4′-bpy], a carboxylato co-ligand (formato or acetato) and an anion (ClO 4 -, NO 3 - or PF 6 -), lead to the formation of the three compounds, namely {[Cu 3(4,4′-bpy) 3(μ-OOCH) 4(H 2O) 2](ClO 4) 2(H 2O) 6} n (1), {[Cu(4,4′-bpy)(μ-OOCH) (NO 3)]} n (2) and {[Cu 2(4,4′-bpy) 2(μ-OOCCH 3) 3](PF 6)(H 2O)} n (3). The molecular structures determined by single-crystal X-ray diffraction reveal notable (4,4) topology, regardless of the different monocarboxylato groups (formato for 1 and 2 and acetato for 3) and anions. Compound 1, synthesized from Cu(II), 4,4′-bpy, ClO 4 - and formate as co-ligand, exhibits a 2D coordination network based on trinuclear chain secondary building units. With coordinating NO 3 - anions (instead of non-coordinating ClO 4 -), a distinct structural motif, i.e. a 2D framework assembled from dinuclear chain secondary building units, is obtained (compound 2). The replacement of the formate ligands by acetate units in compound 3, gives rise to a 2D framework which is assembled from tetranuclear chain secondary building units. The three new coordination compounds have been characterized and tested for their catalytic properties. All compounds show catalytic activities for the selective cyanosilylation of aldehydes. © 2012 Elsevier Ltd. All rights reserved. Source

Wiwanitkit V.,Surindra Rajabhat University
North American Journal of Medical Sciences | Year: 2014

Ebola virus infection is the present global consideration. This deadly virus can result in a deadly acute febrile hemorrhagic illness. The patient can have several clinical manifestations. As a new emerging infection, the knowledge on this infection is extremely limited. The interesting issues to be discussed include a) the atypical clinical presentation, b) new diagnostic tool, c) new treatment, and d) disease prevention. Those topics will be discussed in this special review. © 2014, North American Journal of Medical Sciences. All rights reserved. Source

Stanner M.,Surindra Rajabhat University
Hamadryad | Year: 2012

Recurrent laborious attempts by Varanus salvator to swallow a walking catfish (Clarias sp.) posterio-anteriorly are described. This feeding behaviour is interpreted as a trade-off between immediate gains, i.e. a presumably easy and quick anterior-posterior swallowing and a laborious and lengthy posterior-anterior swallowing, but more secure in the long-run, i.e. in cases of emergency, an anterio-posteriorly swallowed catfish may not be ejected or regurgitated quickly enough (or not at all) due to the backwards pointing spines of the pectoral fins. This trade-off is interpreted as another facet of the life-dinner principle unrelated to its original implication in predator-prey coevolution. Source

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