Advanced Materials Research Vols. 113-116

Abstract: For further researching the structural characteristics of Orientated strand board (OSB) mat, a three-dimensional model was developed using computer-aided design (CAD) technology to simulate behaviors of individual strands in the mat-forming process. This model provided a more realistic description of the mat structure than the previous simulations in using varied strand geometry and different types of strand orientation, defining strand location, and solving the problem of edge effect. This model can be used to analyze the impact of strand orientation on the number of strand overlaps, and to identify the relationship of strand orientation and the horizontal voids distribution in the mat. Information provided by this model is the basis of further studying the effect of the mat formation on panel void characteristics, and the relationship of the voids volume to panel properties.

Abstract: The changes of the surface colors and chemical constituents of Mongolian Scotch pine treated by UV light were investigated by spectrophotometer and FTIR followed by acid pretreatment. The results show that the changes of the surface colors are related to carbonyl, aromatic nucleus, arone, Ar-OH, paraquinones, ortho quinine and so on in the course of UV irradiation. Acid promotes photocycloaddition and plays a hyperchromic effect.

Abstract: Laser cutting is an important application field of laser machining technology. It can improve machining quality and save time by using a computer to simulate the machining process to obtain the optimal process parameters. In the paper, the FEM simulation techniques for laser cutting are discussed by taking wood as an example and using the FEM software ANSYS as a simulation tool. The technologies include solid modeling, finite element meshing, loading of the moving laser source and secondary developing of APDL language. laser cutting; finite element method; simulation

Abstract: The photocatalytic reduction experiments of Cr(VI) over the sulfate-modified titanium-bearing blast furnace slag photocatalyst under UV-vis light irradiation in the absence/presence of citric acid (0≤[citric acid]≤4 mM) were performed at different pH and different initial concentration. In the presence of citric acid, the photocatalytic reduction efficiency of Cr(VI) was significantly enhanced and kinetic constants of the compound system (in the presence of photaocatalyst, citric acid and Cr(VI))was nearly 9.2 times than that in the absence of citric acid. This enhanced efficiency may be attributed to the effective separation of electron-hole in the presence of citric acid. The maximum rate of Cr(VI) reduction was obtained for an initial citric acid/Cr(VI) molar ratio, R=3.75, a further increment in R being disadvantageous; however, the photocatalytic reduction efficiency of Cr(VI) in the presence of citric acid was always faster than in its absence. The synergistic effect factor is always greater than 6 in the compound system, indicating that a marked synergistic effect between the photocatalytic reduction of Cr(VI) and citric acid.

Abstract: A neutralization hydrolysis route has been used to synthesize titanium oxide nanoparticles. Transmission electron microscopy(TEM) and X-ray diffraction(XRD) characteri- zation results showed the TiO2 nanoparticles were single anatase phases when calcined at 600°C-800°C for 2h. The particle diameter ranged from 15 to 30nm. The pH value was key factor for precursor composition. When pH value 2-4, the H2TiO3 precursor with low agglomeration was obtained. As-prepared anatase TiO2 nanoparticles, during photodegradation of methylic orange under UV-light irradiation(λ=254nm), exhibited excellent activity, more than 95.5% methylic orange was degraded in 1h.

Abstract: The volatile components of essential oils of fresh aerial parts from horseweed (Conyza canadensis) collected in October with hydrodistillation and steam distillation, respectively, were analyzed by gas chromatography-mass spectrometry. The results showed that limonene, β-pinene, trans-α-bergamotene, cis-β-ocimene, β-myrcene, germacrene D, 1,3,8-p-menthatriene, caryophyllene, (E)-β-farnesene, (Z)-β-farnesene, α-curcumene, caryophyllene oxide were the common volatile components in the essential oils between hydrodistillation and steam distillation. High limonene content (68.87%) was in the essential oil with hydrodistillation. Limonene or other terpenoids has the potential to develop as the biomimetic synthesis template for environmentally-friendly herbicide.

Abstract: It is well known that bisphenol A(BPA), as one EDC, has an oestrogenic effect, causing an abnormal increase in the growth of yeast cell in polycarbonate flasks. Moreover, BPA significantly contributes to the environment problem, as evidenced by a number of recent studies[1](Inoue et al., 2003). This study examined the ability of nanofiltration (NF) membranes to retain bisphenol A(BPA). In the study, BPA retention was quantified by liquid chromatography. The effect of solution chemistry, inorganic matter and pH were investigated on the rejection of BPA and its adsorption on membranes. The results indicate that BPA has a high adsorptive affinity for the membrane and more than 80% of BPA was absorbed on the membrane surface. In addition, the increase of initial BPA concentration has negative effect on BPA rejection. It also indicates that the removal of BPA is higher with lower BPA concentrations. In addition, the rejection of BPA decreases with the increase of pH when pH < 7 and increases with the increase of pH when pH ≥ 7. The experimental results of ionic strength indicate there is a slight decrease in the rejection of BPA when the ionic strength increases.

Abstract: With boron-rich slag, silica fume, bauxite chalmette and carbon black as starting materials, -sialon powder was prepared by carbothermal reduction nitridation(CRN). The mechanical properties of hot-pressed sintered slag α-sialon ceramic, which was started from slag -sialon powder, were measured. The hardness, toughness and bend strength of hot-pressed slag α-sialon ceramic reached 17GPa, 3.74MPam1/2 and 333.5MPa, respectively. These properties were close to that of chemical α-sialon ceramics prepared by expensive chemical agents as starting materials.

Abstract: N-(3-dehydroabietyloxy-2-hydroxy) propyl-N, N-dimethyl (2-hydroxy) phosphate betaine was synthesized through the 3-dehydroabietyloxy-2-hydroxypropyl chloride and tertiary amine intermediate by using dehydroabietic acid as raw materials. The structure of the target product was confirmed by FT-IR, 1H NMR. The surface-active property was investigated by surface tension experiment. The surface activity of the mixed system of the product and sodium dodecyl sulphate (SDS) was determined. The results showed that critical micelle concentration (CMC) of the product was 1.34 mmol•L-1. Strong synergism in product was observed combining with SDS, and the optimum synergism was obtained at the molar ratio of 1:1.

Abstract: The correlation between PM10 and meteorological factors were investigated, such as wind speed, atmospheric visibility, dew point, relative humidity, and ambient temperature during the brown haze episode. In order to identify the elemental characteristics and concentration features of PM10 during brown haze episode, respirable particulate matter (PM10) was collected during non-haze days and haze days and further analyzed for 20 elements. Among the metallic elements, S, K, Si, and Ca contributed major composition of PM10. S came mainly from coal burning and K was mainly attributed from incinerators and abandoned biomass burning. Furthermore, As was not detectable in non-haze days, while its concentration was 0.15~0.17 μg/m3 in haze days, which would be very much harmful to human health. However, the variation of Sr, Ti, Cr, and Cd was insignificantly, mainly due to low relevance with human activities and/or cross-boundary transportation.