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Although optical remote sensing has been widely used to monitor vegetation characteristics, its use on aboveground vegetation water storage (AVWS) is quite scare. Therefore, we combined the Landsat 8 OLI and Sentinel-1 imageries to quantify AVWS using generalized linear regression (GLM), artificial neural network (ANN) and random forest (RF) with the linkage of field observations in Mao Country, Southwest China. Field observations showed that the AVWS varied significantly among different ecosystems (p < 0.001). In terms of model efficiency and root mean square error, ANN (0.66, 56 Mg ha−1) performed best compared to RF (0.52, 66 Mg ha−1) and GLM (0.48, 69 Mg ha−1). Total AVWS was 3.8 × 107 Mg for the whole study area with 76% contributions from coniferous forests. Strong spatial patterns of AVWS were observed among different ecosystems, which were highly consistent with the spatial distributions of vegetation types. This research highlights a potential way to estimate AVWS through the combination of multispectral remote sensing and SAR data by linking machine learning algorithms, particular in mountainous areas. [ABSTRACT FROM AUTHOR]

Alloy 690TT is a widely used material for steam generator tubes in pressurized water reactors, where it is susceptible to corrosion fatigue. In this study, the effect of loading frequency on the corrosion fatigue behavior of Alloy 690TT in boron-lithium water was investigated under small-scale yielding conditions. Along with stress ratio, the loading frequency had a significant influence on the crack path and fatigue crack growth rate. Both the corrosion fatigue crack growth rate and the environment enhancement factor were quantitatively correlated with the loading frequency in the form of exponential functions. [ABSTRACT FROM AUTHOR]

A basic problem of austentitic stainless steels applied in pressurized water reactors (PWR) is degradation by corrosion fatigue. This paper proposes a prediction model (Nuclear Power Institute of China [NPIC] model) to estimate corrosion fatigue lives of austenitic stainless steels in PWR environments. The NPIC model is built on a corrosion fatigue mechanism and indicates the corrosion fatigue processes better than the ANL model proposed by Argonne National Laboratory. Both the NPIC and ANL models are somewhat conservative in their predictions. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the characteristics of severe periodontitis with various number of tooth loss during 4-year natural progression, and to analyze the factors related to higher rate of tooth loss., Methods: A total of 217 patients aged 15 to 44 years with severe periodontitis were included, who participated in a 4-year natural progression research. Data obtained from questionnaire survey, clinical examination and radiographic measurement. Tooth loss during 4-year natural progression was evaluated. The baseline periodontal disease related and caries related factors were calculated, including number of teeth with bone loss > 50%, number of missing molars, number of teeth with widened periodontal ligament space (WPDL), number of teeth with periapical lesions and etc. Characteristics of populations with various number of tooth loss and the related factors that affected higher rate of tooth loss were analyzed., Results: In 4 years of natural progression, 103 teeth were lost, and annual tooth loss per person was 0.12±0.38. Nine patients lost 3 or more teeth. Thirty-four patients lost 1 or 2 teeth, and 174 patients were absent of tooth loss. Molars were mostly frequent to lose, and canines presented a minimum loss. The number of teeth with WPDL, with periapical lesions, with intrabony defects, with probing depth (PD)≥7 mm, with PD≥5 mm, with clinical attachment loss≥5 mm, with bone loss > 50% and with bone loss > 65% were positively correlated to number of tooth loss. Results from orderly multivariate Logistic regression showd that the number of teeth with bone loss > 50% OR =1.550), baseline number of molars lost ( OR =1.774), number of teeth with WPDL (1 to 2: OR =1.415; ≥3: OR =13.105), number of teeth with periapical lesions (1 to 2: OR =4.393; ≥3: OR =9.526) and number of teeth with caries/residual roots ( OR =3.028) were significant risk factors related to higher likelihood of tooth loss and multiple tooth loss., Conclusion: In 4 years of natural progression, the number of teeth with bone loss > 50%, baseline number of missing molars, number of teeth with WPDL, baseline number of teeth with periapical lesions and number of teeth with caries/residual roots were significantly related to higher risk of tooth loss and multiple tooth loss among Chinese young and middle-aged patients with severe periodontitis in rural areas.