The Effect of Bottom Ash on Soil Suction and Resilient Modulus of Medium-Plasticity Clay

2018 ◽  
Vol 2672 (52) ◽  
pp. 96-107 ◽  
Author(s):  
Arian Asefzadeh ◽  
Leila Hashemian ◽  
Alireza Bayat
Keyword(s):  
Goodness Of Fit ◽  
Prediction Models ◽  
Resilient Modulus ◽  
Bottom Ash ◽  
Soil Suction ◽  
Suction Parameter ◽  
Fit Statistics ◽  
Stress States ◽  
Paper Method ◽  
Medium Plasticity Clay

The effect of adding bottom ash to medium-plasticity clay as a soil stabilizer was evaluated in this study by performing triaxial resilient modulus tests. Two log–log resilient modulus prediction equations found in the literature (MEPDG and NCHRP 1-28) were selected and calibrated for mixtures of bottom ash and clay at different moisture contents. It was found that, with 25% bottom ash in the mixture, the resilient modulus increased between 5% and 23% under different stress states. The soil total and matric suctions of the mixtures were indirectly measured using the filter paper method, and the total suction parameter was incorporated in the two log–log prediction models. The nonlinear regression analysis revealed that the average goodness-of-fit statistics for one of the modified models showed highly satisfactory performance in predicting the resilient modulus values.

Variation of Resilient Modulus with Soil Suction for Compacted Subgrade Soils

2005 ◽  
Vol 1913 (1) ◽  
pp. 99-106 ◽  
Author(s):  
Shu-Rong Yang ◽  
Wei-Hsing Huang ◽  
Yu-Tsung Tai
Keyword(s):  
Moisture Content ◽  
Resilient Modulus ◽  
Matric Suction ◽  
Soil Suction ◽  
Subgrade Soils ◽  
Subgrade Soil ◽  
Relative Compaction ◽  
Service Conditions ◽  
Paper Method ◽  
Key Parameter

The variations of resilient modulus with the postconstruction moisture content and soil suction for cohesive subgrade soils were evaluated. In particular, the effects of relative compaction of the subgrade on the suction and resilient modulus were investigated. To simulate subgrade soils at in-service conditions, soil specimens were compacted at various relative compactions and optimum moisture content and then saturated to equilibrium moisture content to test for resilient modulus and soil suction. The filter paper method was used to measure the total and matric suctions of two cohesive soils. Test findings demonstrated that resilient modulus correlated better with the matric suction than with total suction. Matric suction was found to be a key parameter for predicting the resilient modulus of cohesive subgrade soils. A prediction model incorporating deviator stress and matric suction for subgrade soil resilient modulus was established.

scholarly journals Using Ultrasound and Inflammation to Improve Prediction of Ischemic Stroke: A Secondary Analysis of the Multi-Ethnic Study of Atherosclerosis

2021 ◽  
pp. 37-43
Author(s):  
Hediyeh Baradaran ◽  
Alen Delic ◽  
Ka-Ho Wong ◽  
Nazanin Sheibani ◽  
Matthew Alexander ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Goodness Of Fit ◽  
Primary Outcome ◽  
Stroke Risk ◽  
Secondary Analysis ◽  
Predictor Variables ◽  
Baseline Model ◽  
Fit Statistics ◽  
Ischemic Stroke Risk

Introduction: Current ischemic stroke risk prediction is primarily based on clinical factors, rather than imaging or laboratory markers. We examined the relationship between baseline ultrasound and inflammation measurements and subsequent primary ischemic stroke risk. Methods: In this secondary analysis of the Multi-Ethnic Study of Atherosclerosis (MESA), the primary outcome is the incident ischemic stroke during follow-up. The predictor variables are 9 carotid ultrasound-derived measurements and 6 serum inflammation measurements from the baseline study visit. We fit Cox regression models to the outcome of ischemic stroke. The baseline model included patient age, hypertension, diabetes, total cholesterol, smoking, and systolic blood pressure. Goodness-of-fit statistics were assessed to compare the baseline model to a model with ultrasound and inflammation predictor variables that remained significant when added to the baseline model. Results: We included 5,918 participants. The primary outcome of ischemic stroke was seen in 105 patients with a mean follow-up time of 7.7 years. In the Cox models, we found that carotid distensibility (CD), carotid stenosis (CS), and serum interleukin-6 (IL-6) were associated with incident stroke. Adding tertiles of CD, IL-6, and categories of CS to a baseline model that included traditional clinical vascular risk factors resulted in a better model fit than traditional risk factors alone as indicated by goodness-of-fit statistics. Conclusions: In a multiethnic cohort of patients without cerebrovascular disease at baseline, we found that CD, CS, and IL-6 helped predict the occurrence of primary ischemic stroke. Future research could evaluate if these basic ultrasound and serum measurements have implications for primary prevention efforts or clinical trial inclusion criteria.

Development of Prediction Models for Resilient Modulus of Soils

2021 ◽  
Author(s):  
Cara Fragomeni ◽  
Ahmadreza Hedayat ◽  
William Navidi ◽  
Evan Kuhn ◽  
David Thomas ◽  
...  
Keyword(s):  
Prediction Models ◽  
Resilient Modulus

scholarly journals The role of triiodothyronine (T3) and T3/free thyroxine (fT4) on glucose metabolism during pregnancy: the Ma’anshan Birth Cohort Study

2021 ◽  
Author(s):  
Beibei Zhu ◽  
Yan Han ◽  
Fen Deng ◽  
Kun Huang ◽  
Shuangqin Yan ◽  
...  
Keyword(s):  
Cohort Study ◽  
Glucose Metabolism ◽  
Birth Cohort ◽  
Goodness Of Fit ◽  
Prediction Models ◽  
First Trimester ◽  
Repeated Measurements ◽  
Free Thyroxine ◽  
Birth Cohort Study ◽  
Goodness Of Fit Test

Objectives: Compared with other thyroid markers, fewer studies explored the associations between triiodothyronine (T3) and T3/free thyroxine (fT4) and glucose abnormality during pregnancy. Thus, we aimed to: (1) examine the associations of T3 and T3/fT4 with glucose metabolism indicators; and (2) evaluate, in the first trimester, the performance of the two markers as predictors of gestational diabetes mellitus (GDM) risk. Methods: Longitudinal data from 2723 individuals, consisting of three repeated measurements of T3 and fT4, from the Man’anshan birth cohort study (MABC), China, were analyzed using a time-specific generalized estimating equation (GEE). The receiver operating characteristic curve (ROC) - area under the curve (AUC) and Hosmer-Lemeshow goodness of fit test were used to assess the discrimination and calibration of prediction models. Results: T3 and T3/fT4 presented stable associations with the level of fasting glucose, glucose at 1h/2h across pregnancy. T3 and T3/fT4 in both the first and second trimesters were positively associated with the risk of GDM, with the larger magnitude of association observed in the second trimester (Odds ratio (OR) = 2.50, 95%CI = 1.95, 3.21 for T3; OR = 1.09, 95%CI = 1.07, 1.12 for T3/fT4). T3 ((AUC) = 0.726, 95%CI = 0.698, 0.754) and T3/fT4 (AUC = 0.724, 95%CI = 0.696, 0.753) in the first trimester could improve the performance of the predicting model; however, the overall performance is not good. Conclusion: Significant and stable associations of T3, T3/fT4 and glucose metabolism indicators were documented. Both T3 and T3/fT4 improve the performance of the GDM predictive model.

scholarly journals Models for Tree Taper Form: The Gompertz and Vasicek Diffusion Processes Framework

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 80 ◽  
Author(s):  
Martynas Narmontas ◽  
Petras Rupšys ◽  
Edmundas Petrauskas
Keyword(s):  
Goodness Of Fit ◽  
Diffusion Processes ◽  
Parameters Estimation ◽  
Data Set ◽  
Mixed Effect ◽  
Fit Statistics ◽  
Stem Taper ◽  
Longitudinal Measurements ◽  
High Level ◽  
Taper Models

In this work, we employ stochastic differential equations (SDEs) to model tree stem taper. SDE stem taper models have some theoretical advantages over the commonly employed regression-based stem taper modeling techniques, as SDE models have both simple analytic forms and a high level of accuracy. We perform fixed- and mixed-effect parameters estimation for the stem taper models by developing an approximated maximum likelihood procedure and using a data set of longitudinal measurements from 319 mountain pine trees. The symmetric Vasicek- and asymmetric Gompertz-type diffusion processes used adequately describe stem taper evolution. The proposed SDE stem taper models are compared to four regression stem taper equations and four volume equations. Overall, the best goodness-of-fit statistics are produced by the mixed-effect parameters SDEs stem taper models. All results are obtained in the Maple computer algebra system.

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