Predictive Model for Water Retention Characteristic Curve of Water Absorbing Polymer (WAP) Amended Soil

2021 ◽  
Vol 11 (3) ◽  
pp. 1-24
Author(s):  
A. Saha ◽  
S. Sekharan ◽  
U. Manna
2019 ◽  
Vol 80 (5) ◽  
pp. 929-938
Author(s):  
Janmeet Singh ◽  
Sanjay Kumar Singh ◽  
M. A. Alam

Abstract The understanding of the engineering behaviour of unsaturated soil is totally dependent on the water retention characteristic curve (WRCC). In this paper, a comprehensive study of the WRCCs of pond ash along with the ash's geotechnical behaviour has been made. The WRCC has been drawn experimentally using a Fredlund device based upon the pressure plate technique for both wetting and drying cycles. Further, an investigation was carried out to study WRCC hysteresis of pond ash. There exists a considerable hysteresis in drying and wetting curves of pond ash sample. The different WRCC models were used to fit the experimental WRCC data. The effect of compaction on WRCC was also studied. The air entry value in the case of a loose sample is low and the sample gets nearly desaturated at low soil suction as compared to a dense sample. Also, the wetting WRCC is predicted using the Feng and Fredlund model as it is difficult and time consuming to measure the whole hysteresis. The predicted results are compared with the measured wetting WRCC. Since the direct measurement of unsaturated hydraulic conductivity is difficult to obtain in engineering practices, the unsaturated hydraulic conductivity function is predicted using the measured WRCC as the input parameter using SEEP/W software.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuki Onozato ◽  
Takahiro Nakajima ◽  
Hajime Yokota ◽  
Jyunichi Morimoto ◽  
Akira Nishiyama ◽  
...  

AbstractTumor spread through air spaces (STAS) in non-small-cell lung cancer (NSCLC) is known to influence a poor patient outcome, even in patients presenting with early-stage disease. However, the pre-operative diagnosis of STAS remains challenging. With the progress of radiomics-based analyses several attempts have been made to predict STAS based on radiological findings. In the present study, patients with NSCLC which is located peripherally and tumors ≤ 2 cm in size on computed tomography (CT) that were potential candidates for sublobar resection were enrolled in this study. The radiologic features of the targeted tumors on thin-section CT were extracted using the PyRadiomics v3.0 software package, and a predictive model for STAS was built using the t-test and XGBoost. Thirty-five out of 226 patients had a STAS histology. The predictive model of STAS indicated an area under the receiver-operator characteristic curve (AUC) of 0.77. There was no significant difference in the overall survival (OS) for lobectomy between the predicted-STAS (+) and (−) groups (p = 0.19), but an unfavorable OS for sublobar resection was indicated in the predicted-STAS (+) group (p < 0.01). These results suggest that radiomics with machine-learning helped to develop a favorable model of STAS (+) NSCLC, which might be useful for the proper selection of candidates who should undergo sublobar resection.


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