Prediction of the undrained shear strength of remolded soil with non-linear regression,fuzzy logic,and artificial neural network

This study aims to predict the undrained shear strength of remolded soil samples using non-linear regression analyses,fuzzy logic,and artificial neural network modeling.A total of 1306 undrained shear strength results from 230 different remolded soil test settings reported in 21 publications were collected,utilizing six different measurement devices.Although water content,plastic limit,and liquid limit were used as input parameters for fuzzy logic and artificial neural network modeling,liquidity index or water content ratio was considered as an input parameter for non-linear regression analyses.In non-linear regression analyses,12 different regression equations were derived for the prediction of undrained shear strength of remolded soil.Feed-Forward backpropagation and the TANSIG transfer function were used for artificial neural network modeling,while the Mamdani inference system was preferred with trapezoidal and triangular membership functions for fuzzy logic modeling.The experimental results of 914 tests were used for training of the artificial neural network models,196 for validation and 196 for testing.It was observed that the accuracy of the artificial neural network and fuzzy logic modeling was higher than that of the non-linear regression analyses.Furthermore,a simple and reliable regression equation was proposed for assessments of undrained shear strength values with higher coefficients of determination.

Protective efficacy of Nigella sativa oil against the harmful effects of formaldehyde on rat testicular tissue

Objective: To explore the effects of Nigella sativa oil(NSO) on the histopathological and biochemical changes that inhaled formaldehyde(FA) induces on the testicular tissue of rats. Methods: Thirty three adult male rats were separated into five groups as follows: C, the control group; 4 FA group which received FA for 4 weeks; 13 FA group which was given FA for 13 weeks; 4 FA+NSO group which was administered FA plus NSO for 4 weeks; 13 FA+NSO group which was treated with FA plus NSO for 13 weeks. FA was administered through inhalation for 8 h 5 days a week at a dose of 5 ppm in a special glass cage, and NSO was administered orally 1 mL/kg once daily. Rats were decapitated at the end of the experiment and testicular tissue specimens were harvested for histopathologic and biochemical assessment. Results: Compared to the C group, reduction was observed in the number of intact tubules and in the mean germinative epithelium thickness of the FA groups. Significant increase was observed in the number of intact tubules with the long-term(13 weeks) administration of NSO together with FA. Reduced glutathione peroxidase activity was found and oxidative stress index values were measured higher in the 4 FA and 13 FA groups versus the C group(P<0.05). Moreover, total antioxidant status levels decreased only in the 4 FA group(P<0.05) while only the 13 FA group significantly increased malondialdehyde levels and reduced catalase activities in comparison with the C group. In the 13 FA+NSO group, malondialdehyde levels decreased however glutathione peroxidase and catalase activities increased compared to the 13 FA group. Differences measured in total antioxidant status levels were found to be statistically significant only between the 4 FA and the 4 FA+NSO groups. Conclusions: NSO as an antioxidant should be used for a longer term to achieve protective efficacy both histopathologically and biochemically in the testicular tissue.

Development of Chromium(Ⅲ)-selective Potentiometric Sensor by Using Synthesized Pyrazole Derivative as an lonophore in PVC Matrix and its Applications

A novel poly(vinyl chloride)membrane potentiometric sensor for chromium(Ⅲ)ions based on the use of 5,5′-(1,4-phenylene)bis(3-(naphthalen-1-yl)-4,5-dihydro-1H-pyrazole-1-carbothioamide)as a neutral ionophore was developed.The optimum composition of the best performing membrane contained ionophore,potassium tetrakis(p-chlorophenyl)borate(KTpClPB),dibutyl phthalate(DBP),and poly(vinyl chloride)(PVC)in the ratio of 5.5:1.5:55:38(mg).The sensor exhibits a working concentration range of 1.0×10^(-5)-1.0×10^(-1 )mol L^(−1) and a detection limit of 1.7×10^(-6) mol L^(−1).The sensor shows good selectivity for chromium(III)ions over a number of cations including alkali,alkaline earth,heavy and transition metals.The response time of the sensor is 8 s.In addition,the developed sensor shows good reusability and stability.The sensor operates in the wide pH range of 5.0-11.0.The sensor could be used as an indicator electrode in the quantification of Cr^(3+)ions by potentiometric titration against ethylenediaminetetraacetic acid(EDTA).Finally,this sensor was successfully used for the determination of chromium(III)in commercial water,purification water and wastewater.

National trends in alcohol and substance use among adolescents from 2005 to 2021:a Korean serial cross‑sectional study of one million adolescents

Background Although previous studies have provided data on early pandemic periods of alcohol and substance use in adolescents,more adequate studies are needed to predict the trends of alcohol and substance use during recent periods,including the mid-pandemic period.This study investigated the changes in alcohol and substance use,except tobacco use,throughout the pre-,early-,and mid-pandemic periods in adolescents using a nationwide serial cross-sectional survey from South Korea.Methods Data on 1,109,776 Korean adolescents aged 13–18 years from 2005 to 2021 were obtained in a survey operated by the Korea Disease Control and Prevention Agency.We evaluated adolescents’alcohol and substance consumption prevalence and compared the slope of alcohol and substance prevalence before and during the COVID-19 pandemic to see the trend changes.We define the pre-COVID-19 period as consisting of four groups of consecutive years(2005–2008,2009–2012,2013–2015,and 2016–2019).The COVID-19 pandemic period is composed of 2020(early-pandemic era)and 2021(midpandemic era).Results More than a million adolescents successfully met the inclusion criteria.The weighted prevalence of current alcohol use was 26.8%[95%confidence interval(CI)26.4–27.1]from 2005 to 2008 and 10.5%(95%CI 10.1–11.0)in 2020 and 2021.The weighted prevalence of substance use was 1.1%(95%CI 1.1–1.2)from 2005 to 2008 and 0.7%(95%CI 0.6–0.7)between 2020 and 2021.From 2005 to 2021,the overall trend of use of both alcohol and drugs was found to decrease,but the decline has slowed since COVID-19 epidemic(current alcohol use:βdiff 0.167;95%CI 0.150–0.184;substance use:βdiff 0.152;95%CI 0.110–0.194).The changes in the slope of current alcohol and substance use showed a consistent slowdown with regard to sex,grade,residence area,and smoking status from 2005 to 2021.Conclusion The overall prevalence of alcohol consumption and substance use among over one million Korean adolescents from the early and mid-stage(2020–2021)of the COVID-19 pandemic showed a slower decline than expected given the increase during the prepandemic period(2005–2019).