Girder–Deck Interface: Partial Debonding, Deck Replacement, and Composite Action

Results are reported from tests of three precast, prestressed concrete girders under fatigue-type cyclic and monotonic loading conducted after deck removal and replacement. Although deck demolition altered the top surface of the girders, the girder–deck interfaces exhibited shear strengths greater than their nominal strength (based on the 2012 AASHTO LRFD Specification) after 2 × 106 cycles of loading to 45 and 30% of their nominal strength for troweled and roughened interfaces, respectively. A partially debonded detail was used for two of the girders to protect the girder top flange, which was wide and thin, during deck demolition. The roofing felt used to debond the girder–deck interface over the flanges reduced the effort required for deck removal by 65%, compared with the typical detail, eliminated chipping hammer–induced damage to the girder flanges, and still resulted in sustained composite action under 2 × 106 cycles of loading. The width of the bonded interface had little effect on girder stiffness and no observed effect on the width of deck effective in bending

Composite Action in Prestressed NU I-Girder Bridge Deck Systems Constructed with Bond Breakers to Facilitate Deck Removal

Results are reported from tests of small scale push-off and large-scale composite NU I-girder specimens conducted to establish an interface connection detail that 1) Facilitates in-situ removal of the bridge deck without damaging prestressed girders and 2) Maintains composite action between the prestressed girder and reinforced concrete deck throughout the service-life of the structure. Results are also reported from simple 3D models developed to simulate horizontal shear transfer in composite girders. Sixteen small scale push-off tests were conducted to investigate the influence of surface preparation, bond breakers (epoxy and roofing felt), and interface reinforcement properties (yield strength, reinforcement amount, and means of anchorage) on horizontal shear transfer between precast and cast-in-place concrete surfaces. Based on the push-off test results, a connection detail was proposed that consists of roughening the top flange of the girder directly over the girder web and debonding the remainder of the interface using No. 30 ASTM D4869/D4869M-16a Type I organic roofing felt. Three full-scale composite NU35 girders, designed and fabricated using the proposed connection detail and two control connection details, were then subjected to a series of tests. First, decks were cast and then removed to quantify the extent to which the proposed connection detail reduced the effort to remove the deck and to document the types and extent of damage caused to the girders by the process. After replacing the decks, the composite girders were subjected to 2×106 cycles of simulated traffic load and then loaded monotonically to failure. A series of 3D composite girder models were created in SAP2000 to better understand factors affecting the distribution of slip along the horizontal interface. The girder and deck were simulated using elastic frame and shell elements, respectively, and interface shear was simulated using a series of multilinear link elements. These models were used to simulate the experimental girder tests under service-level loads and to investigate the effects of beam aspect ratio and load position on the distribution of interface shear. The proposed connection (partially roughened/partially debonded with a roofing felt bond breaker) is a viable option for use in practice; its use led to a 2/3 reduction in the effort required to remove the deck over the girder and protected the girder from all non-saw-related damage while also effectively sustaining composite action through 2×106 cycles of simulated traffic load after deck replacement. The proposed connection can be conservatively designed by neglecting the debonded area when calculating interface shear strength. Other test results showed that surface preparation has a large influence on the stiffness, strength at cracking, and peak strength of a horizontal shear connection; each was greatest for specimens with a fully roughened surface followed by the partially roughened surface, troweled surface, and debonded surface. Increasing the amount of interface shear reinforcement increases the initial stiffness, shear strength at cracking, peak and post-peak strength, and does so more effectively than a similar increase in reinforcement yield strength. Casting and removal of bridge decks without bond breakers does alter the top surface of bridge girders, but the surface can be returned to a qualitatively roughened surface with reasonable effort and care. Despite the changes to the top girder surface caused by deck removal, composite action was developed across the interface and remained stable through 2×106 cycles of loading. Finally, the analytical study indicated that models of composite action that consider flexibility of the horizontal shear interface allow for a better estimation of the composite member stiffness and allow for a more accurate assessment of the distribution of slip along the interface than models based on a rigid connection. The interface shear force demand was, however, conservatively estimated for all cases considered with AASHTO provisions

Reliability Assessment of Nanoscale System on Chip Depending on Neturon Irradiation

The atmospheric neutron poses a serious hazard to nanoscale electronics reliability. Spallation neutron irradiations on a nanoscale system on chip (SoC) were conducted applying the China Spallation Neutron Source (CSNS), and the results were compared and analyzed using Monte Carlo simulation. The contribution from thermal neutron on the SoC single event effect (SEE) was analyzed. Analysis indicated the SoC atmospheric neutron SEE vulnerability can be reduced by 44.4% if the thermal neutron was absorbed. The influences of the B and Hf elements on the SEEs were evaluated, too. It can be concluded that 10 B interacting with thermal neutron is the reason for thermal neutron inducing SEE in the SoC. Although the Hf element has no contribution to the 28 nm SoC atmospheric neutron SEE cross section, it increases the total dose risk 5 times during atmospheric neutron irradiation

FgPrp4 Kinase Is Important for Spliceosome B-Complex Activation and Splicing Efficiency in Fusarium graminearum

PRP4 encodes the only kinase among the spliceosome components. Although it is an essential gene in the fission yeast and other eukaryotic organisms, the Fgprp4 mutant was viable in the wheat scab fungus Fusarium graminearum. Deletion of FgPRP4 did not block intron splicing but affected intron splicing efficiency in over 60% of the F. graminearum genes. The Fgprp4 mutant had severe growth defects and produced spontaneous suppressors that were recovered in growth rate. Suppressor mutations were identified in the PRP6, PRP31, BRR2, and PRP8 orthologs in nine suppressor strains by sequencing analysis with candidate tri-snRNP component genes. The Q86K mutation in FgMSL1 was identified by whole genome sequencing in suppressor mutant S3. Whereas two of the suppressor mutations in FgBrr2 and FgPrp8 were similar to those characterized in their orthologs in yeasts, suppressor mutations in Prp6 and Prp31 orthologs or FgMSL1 have not been reported. Interestingly, four and two suppressor mutations identified in FgPrp6 and FgPrp31, respectively, all are near the conserved Prp4-phosphorylation sites, suggesting that these mutations may have similar effects with phosphorylation by Prp4 kinase. In FgPrp31, the non-sense mutation at R464 resulted in the truncation of the C-terminal 130 aa region that contains all the conserved Prp4-phosphorylation sites. Deletion analysis showed that the N-terminal 310-aa rich in SR residues plays a critical role in the localization and functions of FgPrp4. We also conducted phosphoproteomics analysis with FgPrp4 and identified S289 as the phosphorylation site that is essential for its functions. These results indicated that FgPrp4 is critical for splicing efficiency but not essential for intron splicing, and FgPrp4 may regulate pre-mRNA splicing by phosphorylation of other components of the tri-snRNP although itself may be activated by phosphorylation at S289

Improved Neural Radiance Fields Using Pseudo-depth and Fusion

Since the advent of Neural Radiance Fields, novel view synthesis has received tremendous attention. The existing approach for the generalization of radiance field reconstruction primarily constructs an encoding volume from nearby source images as additional inputs. However, these approaches cannot efficiently encode the geometric information of real scenes with various scale objects/structures. In this work, we propose constructing multi-scale encoding volumes and providing multi-scale geometry information to NeRF models. To make the constructed volumes as close as possible to the surfaces of objects in the scene and the rendered depth more accurate, we propose to perform depth prediction and radiance field reconstruction simultaneously. The predicted depth map will be used to supervise the rendered depth, narrow the depth range, and guide points sampling. Finally, the geometric information contained in point volume features may be inaccurate due to occlusion, lighting, etc. To this end, we propose enhancing the point volume feature from depth-guided neighbor feature fusion. Experiments demonstrate the superior performance of our method in both novel view synthesis and dense geometry modeling without per-scene optimization

Reservoir properties and hydrocarbon enrichment law of Chang 1 oil layer group in Yanchang Formation, Wanhua area, Ordos Basin

Evaluation of tight oil reservoir properties is of great significance to the exploration of oil and gas in tight reservoirs. The Chang 1 Member of the Yanchang Formation in the Wanhua Area, Ordos Basin is a new exploration stratum for tight sandstone oil. The lack of understanding of reservoir characteristics and crude oil enrichment rules has seriously restricted the efficient development of oil and gas resources in this stratum. In this study, the reservoir characteristics of the Chang 1 Member in the Wanhua area and the effects of superimposed sand bodies, structures and paleogeomorphology on accumulation of hydrocarbons were systematically studied. The Chang 1 sandstone is a typical ultra-low porosity-ultra-low permeability reservoir, and it has experienced destructive diagenesis of mechanical compaction, pressure solution and cementation, and constructive diagenesis of dissolution. Strong pressure solution caused the secondary enlargement of quartz and feldspar and the formation of patchy dense mosaic structures. The target layer has experienced argillaceous, siliceous and carbonate cementations. Moreover, the sandstone reservoir in the Chang 1 Member also experienced strong dissolution, and it is the main factor for the formation of secondary pores and the improvement of reservoir physical properties. The study also found that the main types of pores in the Chang 1 Member are intergranular dissolved pores and remaining intergranular pores. Superimposed sand bodies, nose-shaped uplifts, dominant facies and eroded paleo-highlands have significant effects on the hydrocarbon accumulation. Based on this study, it was found that the migration and accumulation mode of hydrocarbons in the Chang 1 reservoir belongs to the ladder-like climbing migration + structural ridge accumulation type. In addition, sand body thickness is an important controlling factor for the hydrocarbon accumulation. At present, the discovered crude oil in the Chang 1 Member is always distributed in the areas with thick sand bodies (>20 m), and most of the sand bodies have a thickness in the range of 25–40 m, and the effective thickness is in the range of 2–6 m. In addition, the eroded highlands are the highest topographic units, they are favorable areas for the large-scale accumulation of oil and gas

A Quantitative Rating System for Pollutant Emission Reduction of Asphalt Mixture

This study presents a comprehensive pollutant reduction rating system for hot mix asphalt (HMA) with three Level I indices and ten Level II indices, covering various aspects in HMA pollutant emissions, energy consumption, and exhausts from construction equipment. The pollutant emission reduction effects are investigated not only in the laboratory for modified asphalt mixtures with various mixture gradation and binder types but also in the field for several warm mix asphalt (WMA) projects. Furthermore, energy consumption and emission data during pavement construction are obtained from 58 in situ highway projects in 10 provinces of China. Based on the hierarchical clustering method and Bayesian discriminant analysis, individual ranking systems are developed to quantify pollutant emission reduction effects and energy consumption. Subsequently, a comprehensive reduction rating system is established based on the analytic hierarchy process and approximation methods. A case study is demonstrated to implement the proposed system for the assessment of emission reduction effects