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This paper focuses on improvement effects on soil foundations under dynamic compaction (DC). Firstly, a confocal ellipsoidal densification model (CEDM) composed of a heavy compacted zone (HCZ) and a weak compacted zone (WCZ) was proposed to describe the subarea characteristic of an improvement range. Next, based on a confocal assumption of HCZ and WCZ ellipses, a mass balance equation considering changes in soil dry density in different compacted zones was established for solving the ellipsoidal parameters. Then, a designed laboratory test was conducted and a two-dimensional (2D) finite element model (FEM) established. The simulated crater depth and dynamic stress agreed well with testing results, confirming that the established FEM could be used for investigating the DC process. Finally, the applicability of the solution procedure for the proposed CEDM was verified. The predicted HCZ and WCZ were in close agreement with the simulated results, indicating that the proposed CEDM could be used for estimating the soil improvement range. With increases in tamping times, the HCZ ellipse moved down in the vertical direction without volumetric expansion, while the WCZ ellipse expanded along the depth and lateral directions. These findings may offer some guidelines for research into improvement effects on soil foundation under DC.

To address limitations in conventional static load tests for composite foundations, a method utilizing an elastic cushion layer is proposed to accurately simulate subgrade behavior, focusing on a highway project in Guangdong Province. Initial finite element calculations justify the elastic cushion layer introduction. Functional correlations are established between the stab deformation of the piles and the thickness, modulus and the pile-soil stress ratio. The reasonable value of the elastic modulus is taken as 4 – 10 MPa when the elastic cushion layer thickness is 60 mm. Lab and field tests of cement fly-ash gravel (CFG) pile composite foundations assess settlement variations and pile-soil stress ratios from the proposed improvements. Results reveal the superior performance of the elastic cushion layer over the sand cushion layer, effectively mimicking embankment subgrade layers and reducing rigid constraints on the loading plate. The elastic cushion layer exhibits a significant stress-regulating effect, allowing the transition from the original “100 – 150 mm sand cushion layer + loading plate” to “less than 100 mm sand cushion layer + 60 mm elastic cushion layer (8 MPa) + loading plate”. This adjustment enhances the practical role of the subgrade in the composite foundation, improving the accuracy and feasibility of static load testing methods.

This study attempted to establish a process that uses the ultrasonic wave transmission method to correlate the ultrasonic parameters with the material properties of Foamed Mixture Lightweight Soil (FMLS). The results were then applied for the defect detection of the FMLS embankment. First, the ultrasonic wave velocity (UPV) and amplitude (UPA) of FMLS with different mix proportions were collected continuously from 3rd day to 45th day in the curing age. The relationships between UPV versus FMLS elastic modulus, unconfined compressive strength, and density were calibrated. The variations in the ultrasonic parameters owing to the test distance and crack width were recorded. Then, the laboratory tests were reproduced through numerical simulation approach. Finally, the reliability and accuracy of the proposed detection method for FMLS were proved and validated through on-site tests. The proposed methodology, which is simple, stable, and reliable, was found to be suitable for the quality diagnosis of FMLS embankments after construction and during operation.

This paper proposes an incipient assessment method for postconstruction settlement of highway subgrade by using statistical analysis approach with an improved static loading test method, time-extended loading test. The time-extended loading residual settlement Sr(t) and settlement rate Vs(t) are calculated from the field test data. The test procedure and the corresponding experimental validations are presented. Based on the field test data, a probabilistic model is built to bridge the final residual settlement and the actual postconstruction settlements. The proposed time-extended loading test based assessment system has been validated through three operating and well-documented road sections. According to the validation results, the construction quality can be accurately evaluated at an early stage and the corresponding remedial measures can be applied timely.

Structured illumination microscopy (SIM) surpasses the optical diffraction limit and offers a two-fold enhancement in resolution over diffraction limited microscopy. However, it requires both intense illumination and multiple acquisitions to produce a single high-resolution image. Using deep learning to augment SIM, we obtain a five-fold reduction in the number of raw images required for super-resolution SIM, and generate images under extreme low light conditions (at least 100× fewer photons). We validate the performance of deep neural networks on different cellular structures and achieve multi-color, live-cell super-resolution imaging with greatly reduced photobleaching. Super-resolution microscopy typically requires high laser powers which can induce photobleaching and degrade image quality. Here the authors augment structured illumination microscopy (SIM) with deep learning to reduce the number of raw images required and boost its performance under low light conditions.

Brain extraction and image quality assessment are two fundamental steps in fetal brain magnetic resonance imaging (MRI) 3D reconstruction and quantification. However, the randomness of fetal position and orientation, the variability of fetal brain morphology, maternal organs around the fetus, and the scarcity of data samples, all add excessive noise and impose a great challenge to automated brain extraction and quality assessment of fetal MRI slices. Conventionally, brain extraction and quality assessment are typically performed independently. However, both of them focus on the brain image representation, so they can be jointly optimized to ensure the network learns more effective features and avoid overfitting. To this end, we propose a novel two-stage dual-task deep learning framework with a brain localization stage and a dual-task stage for joint brain extraction and quality assessment of fetal MRI slices. Specifically, the dual-task module compactly contains a feature extraction module, a quality assessment head and a segmentation head with feature fusion for simultaneous brain extraction and quality assessment. Besides, a transformer architecture is introduced into the feature extraction module and the segmentation head. We utilize a multi-step training strategy to guarantee a stable and successful training of all modules. Finally, we validate our method by a 5-fold cross-validation and ablation study on a dataset with fetal brain MRI slices in different qualities, and perform a cross-dataset validation in addition. Experiments show that the proposed framework achieves very promising performance. •A novel two-stage dual-task deep learning framework for fetal MRI slices.•A compact dual-task module for joint brain extraction and quality assessment.•The introduction of a novel transformer architecture for fetal brain MRI processing.•Promising performance on 5-fold cross-validation and cross-dataset validation.

The optimization method to evaluate the tight reservoir porosity is a difficult technique to use due to its complexity and instability. This paper proposes an improved optimization method to calculate the porosity of tight reservoirs. First, we applied the matrix model which modified the multicomponent model to the problem and it improved the results by deducing a mathematical model. Second, we used the Simulated Annealing Algorithm to calculate the incoherence function, and then based on statistical theory, we obtained the most optimal results. Examples show that the method is effective, and despite the lack of the local experience parameters, its application is valuable in order to evaluate the porosity.

A combination of multi-physics numerical simulation and experiment was conducted to study the magnetic pulse compaction technology driven by two aluminum tubes of tungsten copper powder. Then, the effects of different process parameters on the density and uniformity of the compact were studied by tuning the thickness of the pack and driver tubes and the gap between them. Results show that the density of compact is the highest when the thickness of the driver tube is 1.0 mm. More energy is consumed for force conduction as the thickness of the pack tube increases. Thus, the density of the compact is the highest when the thickness of the packer tube is 0.8 mm. The speed of the driver tube impacting the pack tube also increases with the rise in the gap. Accordingly, the compaction density with the gap of 1.5 mm is the highest under the same other parameters.

PurposeTo compare the therapeutic effects of 125I versus non-125I combined with transcatheter arterial chemoembolization (TACE) for the treatment of unresectable hepatocellular carcinoma (HCC) with obstructive jaundice.MethodsA retrospective analysis was conducted using the records of 54 consecutive patients who were initially diagnosed with HCC with obstructive jaundice between May 2009 and July 2016. Twenty-one cases (group A) were treated with percutaneous transhepatic biliary drainage (PTBD) followed by 125I radioactive seed strip implantation through the PTBD tube. After the total serum bilirubin level was reduced to normal and the liver function recovered to Child–Pugh class A or early B, TACE was conducted. In 33 cases (group B) PTBD was performed in combination with TACE without applying the 125I radioactive seeds. The duration of biliary patency and survival were analyzed.ResultsThe technical success rate in both groups was 100%. The median biliary patency time was 6.000 ± 0.315 months (95% CI 5.382–6.618 months) in group A and 4.000 ± 0.572 months (95% CI 2.879–5.121 months) in group B; the two groups were significantly different (P = 0.001). The median survival was 11.000 ± 0.864 months (95% CI 9.306–12.694 months) in group A and 9.000 ± 0.528 months (95% CI 7.965–10.035 months) in group B; the two groups were significantly different (P = 0.022).ConclusionsThe combination of 125I with TACE was more effective than TACE without the radioactive seeds for treating patients with unresectable HCC with obstructive jaundice. Future prospective trials with larger samples will be required to validate these results.

Crimping of wires to achieve a secure connection is one of the most critical challenges in fabrication of electronic circuit boards, automobiles, aviation, satellite and communication components. The electromagnetic pulse crimping process offers great potential to successfully address these challenges. In this paper, ANSYS/Multi physical software was used to first determine the electromagnetic force distribution on the terminal lug by analyzing the magnetic field in the electromagnetic pulse crimping process. The electromagnetic force was then imported into the ABAQUS/Explicit software as the boundary condition to calculate the deformation behavior of the terminal lug barrel and cable according to the stress–strain curve of the terminal material under high strain rate. The calculated deformation result was subsequently verified by experimental data. Three main parameters of the field shaper were analyzed to determine their influence on the crimping result; slit position, the inner diameter vertical dimension and the position relationship between the terminal lug and field shaper. Then using the empirical formula we calculated and verified the inner diameter vertical dimension of the field shaper. The model proved to be reliable. Deformation of the terminal was determined to be uneven along the circumference in the crimping area. For the type of terminal lug studied, an inner diameter vertical dimension of 10 mm proved to be optimum for increased strength of the crimped terminal connection. Allowing the terminal to protrude 1 mm from the field shaper resulted in a flatter crimped area and significant improvement in the quality of the crimped barrel surface. The empirical formula for calculating the inner diameter vertical dimension of the field shaper is reasonable and reliable, and the calculated measurement resulted in improved connection strength. The results of this research can be used to guide the electromagnetic pulse crimping of other terminal lug and cable types.