Experimental study on the performance of compensation grouting in structured soil

Zheng, Gang,Zhang, Xiaoshuang,Diao, Yu,Lei, Huayang Techno-Press 2016 Geomechanics & engineering Vol.10 No.3

Most laboratory test research has focused on grouting efficiency in homogeneous reconstituted soft clay. However, the natural sedimentary soils generally behave differently from reconstituted soils due to the effect of soil structure. A series of laboratory grouting tests were conducted to research the effect of soil structure on the performance of compensation grouting. The effects of grouting volume, overlying load and grouting location on the performance of compensation grouting under different soil structures were also studied. Reconstituted soil was altered with added cement to simulate artificial structured soil. The results showed that the final grouting efficiency was positive and significantly increased with the increase of stress ratio within a certain range when grouting in normally consolidated structured clay. However, in the same low yield stress situation, the artificial structured soil had a lower final grouting efficiency than the overconsolidated reconstituted soil. The larger of normalized grouting volume could increase the final grouting efficiency for both reconstituted and artificial structured soils. Whereas, the effect of the overlying load on final grouting efficiencies was unfavourable, and was independent of the stress ratio. As for the layered soil specimens, grouting in the artificial structured soil layer was the most efficient. In addition, the peak grouting pressure was affected by the stress ratio and the overlying load, and it could be predicted with an empirical equation when the overlying load was less than the yield stress. The end time of primary consolidation and the proportion of secondary consolidation settlement varied with the different soil structures, grouting volumes, overlying loads and grouting locations.

Characteristics and prediction methods for tunnel deformations induced by excavations

Zheng, Gang,Du, Yiming,Cheng, Xuesong,Diao, Yu,Deng, Xu,Wang, Fanjun Techno-Press 2017 Geomechanics & engineering Vol.12 No.3

The unloading effect from excavations can cause the deformation of adjacent tunnels, which may seriously influence the operation and safety of those tunnels. However, systematic studies of the deformation characteristics of tunnels located along side excavations are limited, and simplified methods to predict the influence of excavations on tunnels are also rare. In this study, the simulation capability of a finite element method (FEM) considering the small-strain characteristics of soil was verified using a case study. Then, a large number of FEM simulations examining the influence of excavations on adjacent tunnels were conducted. Based on the simulation results, the deformation characteristics of tunnels at different positions and under four deformation modes of the retaining structure were analyzed. The results indicate that the deformation mode of the retaining structure has a significant influence on the deformation of certain tunnels. When the deformation magnitudes of the retaining structures are the same, the influence degree of the excavation on the tunnel increased in this order: from cantilever type to convex type to composite type to kick-in type. In practical projects, the deformation mode of the retaining structure should be optimized according to the tunnel position, and kick-in deformation should be avoided. Furthermore, two methods to predict the influence of excavations on adjacent tunnels are proposed. Design charts, in terms of normalized tunnel deformation contours, can be used to quantitatively estimate the tunnel deformation. The design table of the excavation influence zones can be applied to determine which influence zone the tunnel is located in.

Numerical and experimental study of multi-bench retained excavations

Zheng, Gang,Nie, Dongqing,Diao, Yu,Liu, Jie,Cheng, Xuesong Techno-Press 2017 Geomechanics & engineering Vol.13 No.5

Earth berms are often left in place to support retaining walls or piles in order to eliminate horizontal struts in excavations of soft soil areas. However, if the excavation depth is relatively large, an earth berm-supported retaining system may not be applicable and could be replaced by a multi-bench retaining system. However, studies on multi-bench retaining systems are limited. The goal of this investigation is to study the deformation characteristics, internal forces and interaction mechanisms of the retaining structures in a multi-bench retaining system and the failure modes of this retaining system. Therefore, a series of model tests of a two-bench retaining system was designed and conducted, and corresponding finite difference simulations were developed to back-analyze the model tests and for further analysis. The tests and numerical results show that the distance between the two rows of retaining piles (bench width) and their embedded lengths can significantly influence the relative movement between the piles; this relative movement determines the horizontal stress distribution in the soil between the two rows of piles (i.e., the bench zone) and thus determines the bending moments in the retaining piles. As the bench width increases, the deformations and bending moments in the retaining piles decrease, while the excavation stability increases. If the second retaining piles are longer than a certain length, they will experience a larger bending moment than the first retaining piles and become the primary retaining structure. In addition, for varying bench widths, the slip surface formation differs, and the failure modes of two-bench retained excavations can be divided into three types: integrated failure, interactive failure and disconnected failure.

Effects of Benzoic Acid and Thymol on Growth Performance and Gut Characteristics of Weaned Piglets

Diao, Hui,Zheng, Ping,Yu, Bing,He, Jun,Mao, Xiangbing,Yu, Jie,Chen, Daiwen Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.6

A total of 144 weaned crossed pigs were used in a 42-d trial to explore the effects of different concentrations/combinations of benzoic acid and thymol on growth performance and gut characteristics in weaned pigs. Pigs were randomly allotted to 4 dietary treatments: i) control (C), basal diet, ii) C+1,000 mg/kg benzoic acid+100 mg/kg thymol (BT1), iii) C+1,000 mg/kg benzoic acid+200 mg/kg thymol (BT2) and, iv) C+2,000 mg/kg benzoic acid+100 mg/kg thymol (BT3). Relative to the control, pigs fed diet BT3 had lower diarrhoea score during the overall period (p<0.10) and improved feed to gain ratio between days 1 to 14 (p<0.05), which was accompanied by improved apparent total tract digestibility of ether extract, Ca and crude ash (p<0.05), and larger lipase, lactase and sucrose activities in the jejunum (p<0.05) at d 14 and d 42. Similarly, relative to the control, pigs fed diet BT3 had higher counts for Lactobacillus spp in digesta of ileum at d 14 (p<0.05), and pigs fed diets BT1, BT2, or BT3 also had higher counts of Bacillus spp in digesta of caecum at d 14 (p<0.05), and lower concentration of ammonia nitrogen in digesta of caecum at d 14 and d 42 (p<0.05). Finally, pigs fed diet BT3 had higher concentration of butyric acid in digesta of caecum at d 42 (p<0.05), and a larger villus height:crypt depth ratio in jejunum and ileum at d 14 (p<0.05) than pigs fed the control diet. In conclusion, piglets fed diet supplementation with different concentrations/combinations of benzoic acid and thymol could improve feed efficiency and diarrhoea, and improve gut microfloral composition. The combination of 2,000 mg/kg benzoic acid+100 mg/kg thymol produced better effects than other treatments in most measurements.

Effects of Benzoic Acid and Thymol on Growth Performance and Gut Characteristics of Weaned Piglets

Hui Diao,Ping Zheng,Bing Yu,Jun He,Xiangbing Mao,Jie Yu,Daiwen Chen 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.6

A total of 144 weaned crossed pigs were used in a 42-d trial to explore the effects of different concentrations/ combinations of benzoic acid and thymol on growth performance and gut characteristics in weaned pigs. Pigs were randomly allotted to 4 dietary treatments: i) control (C), basal diet, ii) C+1,000 mg/kg benzoic acid+100 mg/kg thymol (BT1), iii) C+1,000 mg/kg benzoic acid+200 mg/kg thymol (BT2) and, iv) C+2,000 mg/kg benzoic acid+100 mg/kg thymol (BT3). Relative to the control, pigs fed diet BT3 had lower diarrhoea score during the overall period (p<0.10) and improved feed to gain ratio between days 1 to 14 (p<0.05), which was accompanied by improved apparent total tract digestibility of ether extract, Ca and crude ash (p<0.05), and larger lipase, lactase and sucrose activities in the jejunum (p<0.05) at d 14 and d 42. Similarly, relative to the control, pigs fed diet BT3 had higher counts for Lactobacillus spp in digesta of ileum at d 14 (p<0.05), and pigs fed diets BT1, BT2, or BT3 also had higher counts of Bacillus spp in digesta of caecum at d 14 (p<0.05), and lower concentration of ammonia nitrogen in digesta of caecum at d 14 and d 42 (p<0.05). Finally, pigs fed diet BT3 had higher concentration of butyric acid in digesta of caecum at d 42 (p<0.05), and a larger villus height:crypt depth ratio in jejunum and ileum at d 14 (p<0.05) than pigs fed the control diet. In conclusion, piglets fed diet supplementation with different concentrations/combinations of benzoic acid and thymol could improve feed efficiency and diarrhoea, and improve gut microfloral composition. The combination of 2,000 mg/kg benzoic acid+100 mg/kg thymol produced better effects than other treatments in most measurements.

Expression and Function of GSTA1 in Lung Cancer Cells

Pan, Xue-Diao,Yang, Zhou-Ping,Tang, Qi-Ling,Peng, Tong,Zhang, Zheng-Bing,Zhou, Si-Gui,Wang, Gui-Xiang,He, Bing,Zang, Lin-Quan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.20

Glutathione S-transferase A1 (GSTA1) appears to be primarily involved in detoxification processes, but possible roles in lung cancer remain unclear. The objective of this study was to investigate the expression and function of GSTA1 in lung cancer cells. Real-time PCR and Western blotting were performed to assess expression in cancer cell lines and the normal lung cells, then verify the A549 cells line with stable overexpression. Localization of GSTA1 proteins was assessed by cytoimmunofluorescence. Three double-strand DNA oligoRNAs (SiRNAs) were synthesized prior to being transfected into A549 cells with Lipofectamine 2000, and then the most efficient SiRNA was selected. Expression of the GSTA1 gene in the transfected cells was determined by real-time PCR and Western blotting. The viability of the transfected cells were assessed by MTT. Results showed that the mRNA and protein expression of A549 cancer cells was higher than in MRC-5 normal cells. Cytoimmunofluorescence demonstrated GSTA1 localization in the cell cytoplasm and/or membranes. Transfection into A549 cells demonstrated that down-regulated expression could inhibit cell viability. Our data indicated that GSTA1 expression may be a target molecule in early diagnosis and treatment of lung cancer.

Identification and characterization of BGL11(t), a novel gene regulating leaf-color mutation in rice (Oryza sativa L.)

Zhi-kun Wang,Yun-xiang Huang,Zheng-diao Miao,Zhi-yan Hu,Xin-zhang Song,Li Liu 한국유전학회 2013 Genes & Genomics Vol.35 No.4

A novel bright-green leaf mutant, bgl11, derived from Nipponbare (Oryza sativa L. ssp. japonica) treated by ethyl methanesulfonate (EMS), exhibited a distinct brightgreen leaf phenotype throughout development. Chlorophyll contents of bgl11 decreased significantly than that of its wild-type parent. Genetic analysis suggested that the brightgreen leaf trait was controlled by a single recessive nuclear gene, which was tentatively designed as BGL11(t). To isolate the BGL11(t) gene, a map-based cloning strategy was employed, and the gene was finally mapped in a 94.7 kb region between marker InDel11-5 and InDel11-9 on the long arm of chromosome 11, in which no gene leaded to leaf-color mutation had been mapped or cloned. Cloning and sequencing analysis revealed that, LOC_Os11g38040, which was predicted to encode an expressed protein, had a 9 bp segment deletion in the coding region of bgl11. Furthermore, the transgenic plants with wild-type gene LOC_Os11g38040were restored to normal phenotype. Accordingly, the gene (LOC_Os11g38040) was identified as the BGL11(t) gene. These results are very valuable for further study on BGL11(t)gene and illuminating the mechanism of chloroplast development in rice.

Purification and Characterization of a β-Glucosidase from Aspergillus niger and Its Application in the Hydrolysis of Geniposide to Genipin

( Guo Hong Gong ),( Zhi Ming Zheng ),( Hui Liu,Li Wang ),( Jin Shan Diao ),( Peng Wang ),( Gen Hai Zhao ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.6

An extracellular β-glucosidase from Aspergillus niger Au0847 was purified to homogeneity by precipitation with ammonium sulfate, anion exchange, and gel filtration. The purified protein was composed of two subunits with molecular masses of 110 and 120 kDa. Au0847 β-glucosidase exhibited relatively high thermostability and pH stability, and its highest activity was obtained at 65°C and pH 4.6, respectively. As a potential metalloprotein, its enzymatic activity was potently stimulated by manganese ion and DTT. The β-glucosidase displayed avid affinity and high catalytic efficiency for geniposide. Au0847 β-glucosidase has potential value as an industrial enzyme for the hydrolysis of geniposide to genipin.

A Bama Minipig Model of Laryngopharyngeal Reflux and the Change of Laryngopharyngeal Mucosal Ultrastructure

( Guijian Feng ),( Zhenyu Zhang ),( Chunyan Diao ),( Jun Jiang ),( Shuying Zheng ),( Yulan Liu ) 대한소화기기능성질환·운동학회 2015 Journal of Neurogastroenterology and Motility (JNM Vol.21 No.2

Background/Aims To establish an animal model of laryngopharyngeal reflux (LPR) and study the effect of LPR on the laryngopharyngeal mucosal ultrastructure. Methods Ten Bama minipigs were randomly divided into control group and stent group. Every pig underwent endoscope, and baseline pH was monitored for 4 hours at laryngopharynx and distal esophagus, then specimens from laryngopharyngeal mucosa were biopsied. For the control group, these procedures were repeated on the 14th day. In the stent group, a custom-designed esophageal stent suit was implanted into esophagus, laryngopharyngeal and distal esophageal pH monitoring lasted for 2 hours, then stent suit was removed 3 days later. At last, the same procedures were done as the control group on the 14th day. Specimens were observed under transmission electron microscope to measure the intercellular space and desmosome number. Results In the control group, there was no laryngopharyngeal reflux on the first day and 14th day. Before the stent was implanted, there was also no laryngopharyngeal reflux in the stent group. In both 2 hours and 14 days after stent implantation, the num - ber of reflux, reflux time, and percentage time of pH < 4.0 were significantly increased (P < 0.05) in the stent group. There was no difference in intercellular space and desmosomes in the control group between baseline and 14th day. In the stent group, intercellular space of laryngopharyngeal mucosa was significantly increased (0.37 μm vs 0.96 μm, P = 0.008), and the number of desmosomes was significantly decreased (20.25 vs 9.5, P = 0.003). Conclusions A Bama minipig model of LPR was established by implanting a custom-designed stent suit. LPR might destroy the laryngophar yngeal mucosal barrier. (J Neurogastroenterol Motil 2015;21:182-188)