A novel approach based on non-parametric resampling with interval analysis for large engineering project risks

The issue of risk assessment has been always the matter of debate in large engineering projects (LEPs). The assessment is an indispensable means for the projects to accomplish their objectives. It is firmly accepted that LEPs are particularly subject to more potential risks than other business activities because of their complexity, uncertainty and ambiguity. These characteristics are often conducive to small sample sizes of the gathered risk data in practice. Consequently, traditional statistical techniques cannot contribute significantly to analyze the risk data. The non-parametric resampling technique, namely bootstrap, has been used subsequently to solve numerous complicated problems and evaluate the accuracy of a parameter estimator in situations where commonly used techniques are not valid. It is also more natural, applicable and simple to estimate the risk data in an interval form under decision-making process by considering the concept of safety by professional experts in LEPs. Hence, in this paper, a new approach based on bootstrap technique with the interval analysis is presented in the context of the project risk assessment. The proposed approach not only plays an important role in reducing risk data and saving time but also is more economical. A real case study is conducted to illustrate the applicability of the approach. Finally, the comparison results indicate that the proposed approach outperforms the traditional technique in terms of the accuracy and efficiency.     

Removal of hinosan from underground water using NH4Cl-modified activated carbon from rice husk

Environmental Science and Pollution Research - In the present study, NH4Cl-modified activated carbon was synthesized from rice husk and used as an adsorbent for removal of hinosan from underground...     

Detection of SARS-CoV-2 in the indoor air of intensive care unit (ICU) for severe COVID-19 patients and its surroundings: considering the role of environmental conditions

Environmental Science and Pollution Research - There is ambiguity about the airborne transmission of the SARS-CoV-2. While a distance of 6 feet is considered a safe physical distance, new findings...     

Surfactant-mediated complex formation for determination of traces amounts of zinc, cadmium, and lead with 4-(2-thiazolylazo) resorcinol and chemometric methods

The partial least squares modeling is a powerful multivariate statistical tool applied to the spectrophotometric simultaneous determination of the divalent ions of zinc, cadmium, and lead based on the formation of their complexes with 4-(2-thiazolylazo) resorcinol in surfactant media. The linear concentration range for zinc, cadmium, and lead were 0.10-1.31, 0.148-1.92, and 0.148-3.70 mg L(?-1), respectively. The experimental calibration set was composed of 36 sample solutions using a mixture design for three component mixtures. The absorption spectra were recorded from 380 through 650 nm. The effect of pH on the sensitivity in determination of zinc, cadmium, and lead was studied in order to choose the optimum pH (pH = 8) for determination. The root-mean-square errors of predictions for zinc, cadmium, and lead were 0.0466, 0.0282, and 0.050, respectively. The proposed method was successfully applied for the determination of zinc, cadmium, and lead in water samples.     

A new catalytic oxidation method for sensitive quantification of bromate in flours and bottled water using AgNPs

In this paper, a simple and sensitive spectrophotometric method for the determination of nanomolar level of bromate, based on the catalytic effect of silver nanoparticles on the oxidation of acid red 14 by potassium bromate, is described. The reaction rate was monitored spectrophotometrically by measuring the decrease in absorbance of acid red 14 at 516 nm. The detection limit of the method was 8 ng/mL, and the linear range was between 15 and 130 ng/mL. The effects of acidity, concentration of reactants and reaction time, and external ions were also discussed. The optimum reaction conditions were fixed, and some kinetic parameters determined. The relative standard deviation for the determination of bromate at the concentration of 50 ng/mL was calculated to be 0.996 % (n?=?10). The method has been successfully applied to the determination of bromate in flours and bottled waters.     

Adsorption and photocatalytic properties of porphyrin loaded MIL-101 (Cr) in methylene blue degradation

Environmental Science and Pollution Research - In this study for the very first time, zinc tetraphenylporphyrin (ZnTPP) was loaded into MIL-101 (Zn[TPP]@MIL-101) to perform an adsorptive and...