Advanced Materials Research Vols. 391-392

Abstract: Present work deals with the optimization for flow pattern of continuous phase in a sieve plate extraction column using both computational fluid dynamics (CFD) simulations and particle image velocimetry (PIV) measurements. Firstly single-phase simulation was conducted for the traditional column and it was found that there was a very large reverse flow area between every two plates. Then step by step, by changing the downcomer structure, consisting of inclining downcomers, adding baffles, slotting downcomers and baffles and adjusting the number and size of slots, the reverse flow area was decreased and thereby the flow pattern of continuous phase was optimized. Finally, an optimal flow pattern was obtained with reverse flow area greatly reduced. In order to prove the validity of the simulation results, PIV experiments of two columns were carried out and it was found that the results of simulations and experiments are in good agreement.

Abstract: The flow pattern of the dispersed phase through three types of packings, 700Y rhombus mesh frame packing (RMFP), 350Y polypropylene corrugated sheet packing (PPCSP) andФ16mm plum flower mini ring (PFMR), was observed. According to the characteristics of solvent extraction, a novel hybrid structured packing, consisting of 700Y RMFP and 350Y PPCSP, was developed for liquid-liquid extraction. The mass transfer efficiencies of the novel hybrid structured packing andФ16mm PFMR were investigated in a 150mm diameter column, working with the 30% tributyl phosphate-kerosene (dispersed phase) / acetic / water (continuous phase) system. It is found that the apparent height of mass transfer unit of the hybrid structured packing is 21% smaller than that ofФ16mm PMFR in average under the same experimental condition. It can be concluded that the hybrid structured packing is a high-efficiency packing for liquid-liquid extraction.

Abstract: Three different kinds of imidazoline quaternary ammonium salts were synthesized with the use of valeric acid, decanoic acid, oleic acid, diethylenetriamine, benzyl chloride and thiourea as raw materials. The corrosion inhibition performances on carbon steel in HCl solution were measured via static weight loss method and polarization curve method. Partition coefficients in water and oil were measured, from which thermodynamic parameters of G_0→w、ΔS_0→w and ΔH_0→w were obtained. Temperature effect on the mass transfer between water and oil were examined.Corrosion inhibitor protection is an effective solution to oil field corrosion problems in the acidification process [1]. Most organic inhibitor molecules contain lone pair electrons and rich π-electron such as O, N, S, P atoms or polar groups [2]. Imidazoline compounds contain N nuclei and unsaturated double bond of the larger electronegativity and it has a strong adsorption in the steel surface. Because it has good thermal stability, low toxicity and no irritating odor [3,4], it is considered to be excellent corrosion inhibitors in acidic solution.

Abstract: Residual accelerant from fire debris is the major evidence in the fire investigation. Because all evidences are almost damaged by fire, many isolation methods of analytical chemistry has been already used in extracting trace residue. In this paper, ultrasonic extraction is applied to isolate the residual accelerant and hexane as the solvent. The solution obtained from the residue is tested by GC-MS to analyze their total ion chromatogram (TIC). The chromatographic patterns observed for ignitable liquids are different from the patterns observed for without ignitable liquids. The composition of two samples and content of the fire residues have been analyzed. It’s very important for forensic chemist to distinguish the arson or natural fire.

Abstract: In order to research the residual stress distribution and corrosion resistance of closed extruding fine blanking parts, surface and deep layer residual stress is tested and electrochemical corrosion behavior is also researched through polarization curve test in the 3.5%NaCl solution. The results show that: the surface’s residual stress is compressive stress, compressive stress value increases with the deformation degree, and the maximum value is 150 Mpa or so; Along with increase of depth from surface, residual stress first increases, then decreases, it is on the inferior surface reaches to maximum value, and the influence depth is 200μm; In the polarization curve test, closed extruding fine blanking parts' initial corrosion resistance is better than turning parts and blank, but with the test proceeding, the corrosion resistance drops, and closed extruding fine blanking parts’ final passivation phenomenon delays.

Abstract: A TiO₂-CoFe₂O₄ composite photocatalyst was prepared by one-step method with ultrasound technique using TiCl₄, trivalent iron salt and divalent cobalt salts as precursors. The properties of the sample were investigated by XRD, TEM and VSM techniques. The photocatalyst activity was evaluated by using methyl orange aqueous solution as the model contaminant under the sunlight. The results showed that the TiO₂-CoFe₂O₄ composite photocatalyst exhibited good magnetic properties and the saturation magnetization was 212Gs. The microstructure of samples consists of the TiO₂ with anatase phase and CoFe₂O₄ with spinel structure. The size of TiO₂-CoFe₂O₄ particles is approximately 20 nm in diameter. The photocatalyst test showed highly photocatalytic activity in the sunlight.

Abstract: The newly identified magnetic geometric frustration material-botallackite-structure deuteroxyl copper bromide α-Cu₂(OD)₃Br sample was successfully synthesized in the same single phase (polycrystalline) as the H-isotope substituted sample of α-Cu₂(OH)₃Br, and its IR (4000-400 cm^–1) absorption and Raman (4000-95 cm^–1) spectra at room temperature are first, to the best of our knowledge, measured to study the corresponding relationship between these iso-structural compounds. Through the comparative analysis with those of α-Cu₂(OH)₃Br reported previously, we definitely assign or tentatively suggest their vibration modes according to the result of the factor group analysis.

Abstract: Conventional pesticide applications repeatedly failed to adequately control mosquito and sandfly populations in desert areas, due to effects of intense heat, blowing sand, ultraviolet light and/or combinations of them under severe environmental conditions. The citronellal was copolymerized with vinyl-POSS to enhance the resistant to ultraviolet radiation and thermal stability. The polymerization process between vinyl-POSS and citronellal were simulated by using Dmol³ program of MS software based on DFT. The calculation results showed that the double bonds in vinyl-POSS were initiated easily by phenyl radical, at the same time some double bonds in citronellal were also initiated. After the initiation process, the copolymerization between vinyl-POSS initiated by phenyl radical and citronellal was firstly processed. When the double bonds in vinyl-POSS were run out, the self-polymerizations of citronellal were processed.