Reactive kinetics of carbon dioxide loaded aqueous blend of 2-amino-2-ethyl-1,3-propanediol and piperazine using a pressure drop method

In this study, a new pressure drop method has been used to investigate the kinetics of carbon dioxide reaction with aqueous blend of 2-amino-2-ethyl-1,3-propanediol (AEPD) with piperazine (PZ). The blending of a small amount of PZ with AEPD has a significant effect on the observed rate constant, k_obs. It was observed that k_obs values of the blend increased more than twice than the summation of k_obs values of individual alkanolamines. The reaction kinetics in this study were modeled by assuming a termolecular mechanism. The addition of 0.1 mol/L of PZ to 1 mol/L AEPD exhibited an observed rate constant, k_obs of 8824.1 s⁻¹, which is comparable to other alkanolamine mixtures. Hence, PZ/AEPD mixtures can be potentially used for rapid carbon dioxide capture.     

FT‐Raman,FT‐IR spectral and DFT studies on 6, 8‐dichloroflavone and 6, 8‐dibromoflavone

In this study, experimental and theoretical vibrational spectral results of the molecular structures of 6,8‐dichloroflavone (6,8‐dcf) and 6,8‐dibromoflavone (6,8‐dbf) are presented. The FT‐IR and FT‐Raman spectra of the compounds have been recorded together between 4000 and 400 cm⁻¹ and 3500–5 cm⁻¹ regions, respectively. The molecular geometry and vibrational wavenumbers of 6,8‐dcf and 6,8‐dbf in their ground state have been calculated by using DFT/B3LYP functional, with 6‐31 + + G(d,p) basis set used in calculations. All calculations were performed with Gaussian03 software. The obtained vibrational wavenumbers and optimized geometric parameters were seen to be in good agreement with the experimental data. Scale factors have been used in order to compare how the calculated and experimental data are in agreement. Theoretical infrared intensities are also reported. Copyright © 2009 John Wiley & Sons, Ltd.     

Circular neighbor-balanced designs using cyclic shifts

In agriculture experiments, the response on a given plot may be affected by the treatments on neighboring plots as well as by the treatments applied to that plot. In this paper we consider such type of situations and construct circular neighbor-balanced designs (CNBDs) by the method of cyclic shifts or sets of shifts. An important feature of this method is that the properties of a design can be easily obtained from the sets of shifts instead of constructing the actual blocks of the design. That is, the off-...     

Facile synthesis and characterization of functionalized, monocrystalline rutile TiO2 nanorods

Functionalized, monocrystalline rutile TiO2 nanorods were prepared from TiCl4 in aqueous solution under acidic conditions in the presence of dopamine, followed by aging and hydrothermal treatment at 150 degrees C. The surface-bound organic ligand controls the morphology as well as the crystallinity and the phase selection of TiO2. The presence of monocrystalline rutile TiO2 was confirmed by X-ray powder diffraction and HRTEM investigations. The as-prepared nanorods are soluble in water at pH <3. The surface functionalization was analyzed by IR and 1H NMR, confirming the presence of dopamine on the surface. The surface amine groups can be tailored further with functional molecules such as dyes. Confocal laser scanning microscopy (CLSM) was used to characterize the binding of the fluorescent dye 4-chloro-7-nitrobenzofurazan (NBD) to the functionalized surface of the TiO2 nanorods.     

Monitoring of <Superscript>137</Superscript>Cs in electric arc furnace steel making process

This article presents the results of ¹³⁷Cs and other radionuclide monitoring in EAF steel-making process in the Croatian CMC Sisak Steel Mill. The presence of ¹³⁷Cs and natural isotopes ⁴⁰K, ²³²Th, ²²⁶Ra and ²³⁸U was established. Investigations on the occurrence of the isotope cesium, as well as natural isotopes and their distribution in waste from the process of carbon steel production by EAF have been conducted. Detection of artificial isotope cesium in EAF dust indicates that it might originate from steel scrap or from the residue of the material that was used in the technological process, thus deserving special attention.     

Self-assembly of luminescent ternary complexes between seven-coordinate lanthanide(III) complexes and chromophore bearing carboxylates and phosphonates

Luminescent lanthanide complexes have been prepared by exploiting the interaction between lanthanide DO3A complexes and chromophore bearing carboxylates or phosphonates. This interaction can be utilised to probe the choice of sensitising chromophore suited to a given lanthanide. Furthermore, ternary complexes obtained from chromophore appended carboxylates dissociate in the presence of phosphate, while those obtained from phosphonates do not.     

Computational Materials Chemistry at the Nanoscale

In order to illustrate how atomistic modeling is being used to determine the structure, physical, and chemical properties of materials at the nanoscale, we present here the results of molecular dynamics (MD) simulations on nanoscale assemblies of such materials as carbon nanotubes, diamond surfaces, metal alloy nanowires, and ceramics. We also include here the results of nonequilibrium MD simulations on the nanorheology of a monolayer of wear inhibitor self-assembled on two metal oxide surfaces, separated by hexadecane lubricant, and subjected to steady state shear.We also present recent developments in force fields (FF) required to describe bond breaking and phase transformations in such systems. We apply these to study of plasticity in metal alloy nanowires where we find that depending on the strain rate, the wire may deform plastically (forming twins), neck and fracture, or transition to the amorphous phase.