Design optimization and application of bolt-shotcrete support for East Tianshan tunnel project in China

Bolt-shotcrete support is a form of support with low cost, convenient for construction, uniform structural stress, which is widely used in international tunnel engineering. In this paper, the 2# inclined shaft of East Tianshan tunnel in China is taken as the research object. The stress characteristics of composite lining support and bolt-shotcrete support are analyzed and compared by FLAC3D software, and the bolt-shotcrete support scheme suitable for this project is put forward. Based on the principle of orthogonal experiment, the most reasonable shotcrete material proportion is selected, and structural stress and displacement monitoring is carried out during the construction stage of typical sections. The results show that: (1) in FLAC3D simulation calculation, the interface element is applied between different layers, which can simulate the interaction between different layers of lining structure and reflect the mechanical characteristics and displacement characteristics of the interface between layers; (2) from the aspect of mechanical performance, single layer lining which can meet the requirements of tunnel support with thinner structural thickness and has higher economic efficiency, is better than composite lining; (3) the field monitoring results show that the deformation of bolt-shotcrete support structure is small, the structural stress meets the material performance requirements, and there is no structural damage during the construction of the test section; (4) during the implementation of bolt-shotcrete support, the cost of support per meter is reduced by 36.78%, and the average excavation efficiency is increased by 38.9%, which verifies the applicability and advantages of the optimization scheme. The research results in this paper can provide reference for the follow-up construction of tunnels and similar projects. Please click Additional Files below to see the full abstract

Novel Compact Multiband MIMO Antenna for Mobile Terminal

A novel compact MIMO antenna for personal digital assistant (PDA) and pad computer is proposed. The proposed antenna is composed by two multipatch monopole antennas which are placed 90° apart for orthogonal radiation. To strengthen the isolation, a T-shaped ground branch with proper dimension is used to generate an additional coupling path to lower the mutual coupling (below −15 dB), especially at GSM850/900 band. The proposed MIMO antenna is fabricated and tested, both the simulated and the measured results are presented, and some parametric studies are also demonstrated. In addition, there are some advantages about the proposed antenna such as simple structure, easy fabrication, and low cost

Simultaneous tracking of fly movement and gene expression using GFP

<p>Abstract</p> <p>Background</p> <p>Green Fluorescent Protein (GFP) is used extensively as a reporter for transgene expression in Drosophila and other organisms. However, GFP has not generally been used as a reporter for circadian patterns of gene expression, and it has not previously been possible to correlate patterns of reporter expression with 3D movement and behavior of transgenic animals.</p> <p>Results</p> <p>We present a video tracking system that allows tissue-specific GFP expression to be quantified and correlated with 3D animal movement in real time. <it>eyeless/Pax6 </it>reporter expression had a 12 hr period that correlated with fly activity levels.</p> <p><it>hsp70 </it>and <it>hsp22 </it>gene reporters were induced during fly aging in circadian patterns (24 hr and 18 hr periods, respectively), and spiked in the hours preceding and overlapping the death of the animal. The phase of <it>hsp </it>gene reporter expression relative to fly activity levels was different for each fly, and remained the same throughout the life span.</p> <p>Conclusion</p> <p>These experiments demonstrate that GFP can readily be used to assay longitudinally fly movement and tissue-specific patterns of gene expression. The <it>hsp22</it>-GFP and <it>hsp70</it>-GFP expression patterns were found to reflect accurately the endogenous gene expression patterns, including induction during aging and circadian periodicity. The combination of these new tracking methods with the <it>hsp</it>-GFP reporters revealed additional information, including a spike in <it>hsp22 </it>and <it>hsp70 </it>reporter expression preceding death, and an intriguing fly-to-fly variability in the phase of <it>hsp70 </it>and <it>hsp22 </it>reporter expression patterns. These methods allow specific temporal patterns of gene expression to be correlated with temporal patterns of animal activity, behavior and mortality.</p

Apparatus and process for freeform fabrication of composite reinforcement preforms

A solid freeform fabrication process and apparatus for making a three-dimensional reinforcement shape. The process comprises the steps of (1) operating a multiple-channel material deposition device for dispensing a liquid adhesive composition and selected reinforcement materials at predetermined proportions onto a work surface; (2) during the material deposition process, moving the deposition device and the work surface relative to each other in an X-Y plane defined by first and second directions and in a Z direction orthogonal to the X-Y plane so that the materials are deposited to form a first layer of the shape; (3) repeating these steps to deposit multiple layers for forming a three-dimensional preform shape; and (4) periodically hardening the adhesive to rigidize individual layers of the preform. These steps are preferably executed under the control of a computer system by taking additional steps of (5) creating a geometry of the shape on the computer with the geometry including a plurality of segments defining the preform shape and each segment being preferably coded with a reinforcement composition defining a specific proportion of different reinforcement materials; (6) generating programmed signals corresponding to each of the segments in a predetermined sequence; and (7) moving the deposition device and the work surface relative to each other in response to these programmed signals. Preferably, the system is also operated to generate a support structure for any un-supported feature of the 3-D preform shape

Stability Analysis and Reinforcement of the Existing Karst Cave Passing through Yujingshan Tunnel

High-speed Railway tunneling in karst terrain presents a huge challenge to the engineer including the identification, stability analysis and reinforcement of the karst cavities. The Cheng-Gui high-speed railway tunnel had to pass through the largest karst cave discovered in tunnel construction. To guaranteeing the tunnel construction safety, a series of corresponding prevention and control measures are put forward. To begin with, geological drilling, electromagnetic method and surface electrical resistivity tomography are adopted to detect and delineate the underground karst zone. Based on the detection results, this paper has put forward strategies to make the pre-support of karst cave and the main technical of those strategies include: the side-walls or in the crown was applied with shotcret (C40 steel fiber concrete); use expanding-shell pre-stressed hollow anchor rod and pre-stressed cable reinforcement; fix steel-mesh-bolting; the shotcrete sealing was applied. Moreover, if instabilities would develop in the side-walls, it should be sufficient to stabilize the cavities, to do dental cleaning of the broken rocks, and fill the voids with shotcrete or pumped lean concrete. At last, systematic grouting treatment around the excavated section, and was excavated with the layer-step method. The solutions presented here may provide guidance for the design and construction of high-speed railway tunnels to be implemented affected by karst processes. The technical validation of the proposed solutions was demonstrated by the successful completion of the Yujingshan tunnel. Please click Additional Files below to see the full abstract

Simultaneous tracking of movement and gene expression in multiple Drosophila melanogaster flies using GFP and DsRED fluorescent reporter transgenes

<p>Abstract</p> <p>Background</p> <p>Fluorescent proteins such as GFP (Green Fluorescent Protein) and DsRED (Discosoma sp.<it/>Red Fluorescent Protein) are often used as reporter molecules for transgene expression in Drosophila<it/> and other species. We have recently reported methods that allow simultaneous tracking of animal movement and GFP expression in real time, however the assay was limited to single animals and a single transgene. Numerous studies would be facilitated by methods that allow for assay of multiple animals and multiple transgenes.</p> <p>Findings</p> <p>Here we report an improved fly video tracking system that allows multiple transgenic flies to be tracked simultaneously using visible light, GFP fluorescence and DsRED fluorescence. The movement of multiple flies could be accurately tracked at real time rates, while simultaneously assaying the expression level of two different transgenes marked with GFP and DsRED. The individual flies could be accurately tracked and distinguished even during periods when transgene fluorescence was undetected. For example, characteristic patterns of <it>hsp70 </it>and <it>hsp22 </it>transgene induction could be simultaneously quantified and correlated with animal movement in aging flies, and as groups of flies died due to dessication/starvation.</p> <p>Conclusion</p> <p>The improved methods allow for more efficient assay of the correlation between gene expression, behavior, aging and mortality: multiple animals can be assayed with simultaneous quantification of multiple transgenes using GFP and DsRED fluorescence. These methods should allow for increased flexibility in experimental designs. For example, in the future it should be possible to use gene expression levels to predict remaining life span more accurately, and to quantify gene expression changes caused by interactions between animals in real time.</p

Multiscale Permutation Entropy Based Rolling Bearing Fault Diagnosis

A new rolling bearing fault diagnosis approach based on multiscale permutation entropy (MPE), Laplacian score (LS), and support vector machines (SVMs) is proposed in this paper. Permutation entropy (PE) was recently proposed and defined to measure the randomicity and detect dynamical changes of time series. However, for the complexity of mechanical systems, the randomicity and dynamic changes of the vibration signal will exist in different scales. Thus, the definition of MPE is introduced and employed to extract the nonlinear fault characteristics from the bearing vibration signal in different scales. Besides, the SVM is utilized to accomplish the fault feature classification to fulfill diagnostic procedure automatically. Meanwhile, in order to avoid a high dimension of features, the Laplacian score (LS) is used to refine the feature vector by ranking the features according to their importance and correlations with the main fault information. Finally, the rolling bearing fault diagnosis method based on MPE, LS, and SVM is proposed and applied to the experimental data. The experimental data analysis results indicate that the proposed method could identify the fault categories effectively

DNA methylation regulator-based molecular subtyping and tumor microenvironment characterization in hepatocellular carcinoma

BackgroudAlthough recent studies have reported the regulation of the immune response in hepatocellular carcinoma (HCC) through DNA methylation, the comprehensive impact methylation modifications on tumor microenvironment characteristics and immunotherapy efficacy has not been fully elucidated.MethodsIn this research, we conducted a comprehensive assessment of the patterns of DNA methylation regulators and the profiles of the tumor microenvironment (TME) in HCC, focusing on 21 specific DNA methylation regulators. We subsequently developed a unique scoring system, a DNA methylation score (DMscore), to assess the individual DNA methylation modifications among the three distinct methylation patterns for differentially expressed genes (DEGs).ResultsThree distinct methylation modification patterns were identified with distinct TME infiltration characteristics. We demonstrated that the DMscore could predict patient subtype, TME infiltration, and patient prognosis. A low DMscore, characterized by an elevated tumor mutation burden (TMB), hepatitis B virus (HBV)/hepatitis C virus (HCV) infection, and immune activation, indicates an inflamed tumor microenvironment phenotype with a 5-year survival rate of 7.8%. Moreover, a low DMscore appeared to increase the efficacy of immunotherapy in the anti-CTLA-4/PD-1/PD-L1 cohort.ConclusionsIn brief, this research has enhanced our understanding of the correlation between modifications in DNA methylation patterns and the profile of the tumor microenvironment in individuals diagnosed with HCC. The DMscore may serve as an alternative biomarker for survival and efficacy of immunotherapy in patients with HCC