دانلود گزارش کارورزی و کار آموزی

چکیده : 

The pile signal matching technique widely used for estimating vertical resistances of piles during construction

is highly influenced by the assumed dynamic soil parameters. Due to the lack of understanding

and supporting data, constant soil parameters for the entire pile length have been routinely used. This

practice is unrealistic and compromises the signal match quality. Using recently completed field tests,

this paper develops empirical equations for dynamic soil parameters in terms of measureable soil properties

and proposes an improved signal matching technique, thereby allowing for better match quality

چکیده : 

Accurate prediction of ground surface settlement is necessary for effectively controlling the settlement

that develops during tunneling. Many models have been established for this purpose by extracting the

relationship between the settlement and the factors that influence it. However, most of the models

focused on the maximum ground surface settlement and do not involve dynamic and real-time predictions.

This paper investigated how tunneling-induced ground surface settlement developed using a

smooth relevance vector machine with a wavelet kernel (wsRVM). Various factors that affect this settlement,

including geometrical, geological and shield operational parameters were considered. The model

was applied to earth pressure balance (EPB) shield-driven tunnels. The results indicate that the prediction

model performs well and that the distribution of the predictions can provide a measure of the prediction

uncertainty. Unlike conventional methods that requireadditional efforts to determine relevant model

parameters, the proposed method can optimize the parameters in the training process. The results of

the parametric study conducted show that the model performance can be improved by the optimization

and that the method can serve as a simple tool for practitioners to use in estimating ground surface settlement

development during tunneling

چکیده : 

In this study, upper bound finite element (FE) limit analysis is applied to stability problems of slopes

using a nonlinear criterion. After formulating the upper bound analysis as the dual form of a second-order

cone programming (SOCP) problem, the stress field and corresponding shear strength parameters can be

determined iteratively. Thus, the nonlinear failure criterion is represented by the shear strength parameters

associated with stress so that the analysis of slope stability using a nonlinear failure criterion can be

transformed into the traditional upper bound method with a linear Mohr–Coulomb failure criterion.

Comparison with published solutions illustrates the accuracy and feasibility of the proposed method

for a simple homogeneous slope stability problem. The proposed approach is also applied to a seismic

stability problem for a rockfill dam to study the influence of different failure criterions on the upper

bound solutions. The results show that the seismic stability coefficients obtained using two different nonlinear

failure criteria are similar but that the convergence differs significantly

چکیده : 

Plant growth promoting rhizobacteria (PGPRs) are used for biocontrol of bacterial wilt caused by Ral-stonia solanacearum. They are commonly isolated from the rhizosphere of healthy plants and are scarcein the rhizosphere of diseased plants. We hypothesized that a pathogen-prevalent environment, suchas the rhizosphere of infected plants, would be a good or better source for isolating PGPRs than therhizosphere of healthy plants. In order for these PGPRs to survive successfully in a pathogen-prevalentenvironment, they must have particularly well-developed survival strategies under the stresses exertedby pathogen activities, which would be of value for their use as biocontrol agents. To test this hypothesis, R.solanacearum-antagonistic bacteria were screened from the rhizospheres of diseased and healthy tomatoplants. In total, 110 rhizobacteria were isolated, 18 of which showed antagonism to R. solanacearumin vitro. Among the 18 antagonistic strains, 11 (out of 60) were from the rhizosphere of diseased plants,with inhibition diameter zones ranging from 11.2 to 15.2 mm, whereas 7 (out of 50) were from the rhi-zosphere of healthy plants, with inhibition diameter zones ranging from 11.5 to 30.5 mm. Strains WR4,WR21, and WR42 from diseased plants rhizosphere, and HR61, HR62, and HR92 from healthy plants rhi-zosphere, were chosen to investigate their biocontrol efficacies (BCEs) in greenhouse condition. Resultsshowed that WR-isolates performed better in reducing disease incidence (DI) than those HR-isolates. Pop-ulation densities of R. solanacearum in the rhizosphere soil and crown section of tomato plants were lowerin WR-isolate treatments than those in HR-isolate treatments. The best biocontrol effect was achievedby inoculating the strain WR21, followed by WR4, WR42, HR92, HR62, and HR61. Root colonization testshowed WR21 had the highest root-colonizing capacity compared with 5 other antagonists. BCEs werepositively () correlated with root-colonizing capacities, but were negatively (r = −0.797) corre-lated with inhibition zones. In conclusion, the rhizosphere of diseased tomato plants is a good reservoirof biocontrol bacteria.

چکیده : 

The Fusarium wilt in cucumbers, caused by the pathogenic fungus Fusarium oxysporum f. sp. cucumerinum,is a serious and destructive disease worldwide. An effort was made to explore the role of Trichodermaharzianum T-E5 in reducing the incidence of Fusarium wilt. Three treatments (Control, T1, and T2) wereestablished in the greenhouse experiment. The effects of T-E5 on the composition of root exudates andfungal community in the cucumber rhizosphere were measured. Compared with the control, the applica-tion of a bio-organic fertilizer (BIO) enriched with T-E5 was found to decrease the incidence of Fusariumwilt notably and promote the growth of cucumber plants. Based on real-time PCR, the population of F.oxysporum in the control without T-E5 increased from 103to 104ITS copies g−1soil, whereas the popu-lation decreased from 103to 102ITS copies g−1soil in the T1 and T2 treatment groups when T-E5 wasincluded. Significant difference in fungal community was also found among the treatment groups. HPLCanalysis showed that the detected levels of phenolic compounds in control were significantly higher thanthe levels in the samples subjected to T1 and T2 treatments. The root exudates from the control groupsignificantly increased the numbers of germinating spores of the pathogen compared with those fromthe samples treated with T1 and T2. In conclusion, the modification of root exudates and the fungal com-munity by the application of BIO might account for the effective suppression of Fusarium wilt disease incucumbers.