No abstract

Rice straw hydrolysate was used as lignocellulose-based carbon source for Chlorella pyrenoidosa cultivation and the feasibility of in situ biodiesel production was investigated. 13.7 g/L sugar was obtained by enzymatic hydrolyzation of rice straw. Chlorella pyrenoidosa showed a rapid growth in the rice straw hydrolysate medium, the maximum biomass concentration of 2.83 g/L was obtained in only 48 hours. The lipid content of the cells reached as high as 56.3%. In situ transesterification was performed for biodiesel production. The optimized condition was 1 g algal powder, 6 mL n-hexane, and 4 mL methanol with 0.5 M sulfuric acid at the temperature of 90°C in 2-hour reaction time, under which over 99% methyl ester content and about 95% biodiesel yield were obtained. The results suggested that the method has great potential in the production of biofuels with lignocellulose as an alternative carbon source for microalgae cultivation.

No abstract

Shield tunneling adjacent to pile groups is always an unavoidable problem in urban metro construction. A case was found in the project of Tianjin Metro Line 7, where a shield tunnel would be constructed near the existing pile groups of Shiyou Bridge. The whole shield tunnel is close to pile groups, and the minimum distance is only 0.8 m. Therefore, four kinds of protective schemes are proposed in this paper. It is vital to select an appropriate protective scheme to guarantee the safety during the tunnel construction. In this study, the main mechanical characteristic and physical parameters of site soil were obtained through laboratory tests. Besides, the three-dimensional finite element method was carried out to compare and analyze the effectiveness of the protective schemes in mitigating the effects of tunneling on adjacent pile groups. The results show that the deep-hole grouting scheme has better control effect on the lateral deformation and bending moment of piles, while the pile foundation underpinning scheme has better effectiveness on reducing the settlement of bridge structure and ground deformation. Finally, the deep-hole grouting reinforcement scheme will be adopted to ensure the shield passing through the pile groups smoothly.

In this letter, we propose a novel method for upsampling the noisy low resolution depth map with the guidance of the companion color image. The problem is modeled with an Markov Random Field (MRF)-based optimization framework. The novelty relies on the smoothness term that is modeled with an exponential function as the error norm. By using this novel error norm, our method can take the property of the depth map into account. Depth discontinuity cues are not only obtained from the color image but also the depth map itself. Our method has much better performance in preserving sharp depth discontinuities and suppressing the texture copy artifacts. Experimental results show that our method outperforms state-of-art solutions in both visual quality and accuracy.