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The glass system of composition (AgPO3)1-x (Ag2SO4)x [where x = 0, 0.15, 0.20, 0.25 Mol%] was prepared using the conventional melt quenching technique. The molar volume and density were determined to characterise the structure of the glasses obtained. X-ray diffraction was used to confirm the amorphous nature of the glass samples used. The absorbance and transmittance were measured in the spectral range of 200–3000 nm for the prepared glasses by using UV-Vis two-beam spectrophotometer. A new modified equation has been formulated to determine the refractive index of the glasses used. Dispersive power, energy gap, dispersion energy and oscillator energy were measured as well. Also, molar refractivity, molecular polarisability and metallization criterion for the glass samples of different Ag2SO4 concentrations were calculated. [ABSTRACT FROM AUTHOR]

Steel manufacturing factories usually dump byproduct recycled steel randomly in open areas, creating environmental hazards. Using such materials in highway construction could be a solution to the environmental hazards generated from their disposal. A combined method of physical and chemical stabilization was used in this study to investigate the value of using mill scale (MS) and cementitious materials in improving the strength and deformation properties of subgrade soil. The results showed that MS additives effectively reduced plasticity and increased maximum dry unit weight, unconfined compression strength (UCS), and California bearing ratio (CBR). Subgrade soil with 20% MS was treated with cement and lime to obtain a strength value of 1.7 MPa (after 7 days of curing) for subbase application. A repeated load triaxial (RLT) device was used to perform resilient modulus (MR) and permanent deformation tests in order to evaluate the response of laboratory-molded stabilized specimens under cyclic loading in accordance with a standard testing procedure. Study findings are explained through a microstructural analysis that used scanning electron microscopy (SEM) supplied with energy-dispersive X-ray spectroscopy (SEM/EDX). The test results showed that, in addition to solving the MS disposal problem, the use of MS as an additive had a favorable influence on the geotechnical properties of the soil. [ABSTRACT FROM AUTHOR]

The most commonly studied generalized normal distribution is the well-known skew-normal by Azzalini. In this paper, a new generalized normal distribution is defined and studied. The distribution is unimodal and it can be skewed right or left. The relationships between the parameters and the mean, variance, skewness, and kurtosis are discussed. It is observed that the new distribution has a much wider range of skewness and kurtosis than the skew-normal distribution. The method of maximum likelihood is proposed to estimate the distribution parameters. Two real data sets are applied to illustrate the flexibility of the distribution. [ABSTRACT FROM AUTHOR]

Limiting number of fatalities and reducing injury severity of car crashes is a continuing global concern. This study investigates crash risk factors including driver, vehicle, roadway, and crash characteristics role in determining injury severity levels encountered by drivers in fatal car crashes. Three types of supervised machine learning techniques were used; Classification and Regression Tree (CART), Artificial Neural Networks (ANN) and Multinomial Logistic Regression. The CART model was used to elect the most influential factors in determining drivers' injury severity levels. The ANN model was used to predict drivers' injury severity based on crash attributes. The logistic model was used to identify the effect of different crash attributes in distinguishing drivers' injury severity levels and for comparison purposes. Consequently, CART model resulted in six significant factors, these factors are: airbag deployment, seatbelt use, driver age, vehicle rollover, collision type, and vehicle model year. It was found that airbag deployment has a strong correlation with severe injuries and even fatalities. The use of seatbelts appears to reduce injuries and fatalities. Furthermore, elderly drivers, front to front collisions, vehicle rollover and older vehicles seem to cause more mortalities and injuries. On the other hand, according to the logistic model, all the crash attributes were found significant in distinguishing between drivers' injury severity levels except for the roadway functional system. However, the ANN model outperformed the CART model in terms of accuracy and stability. Further, both models seem to outperform the logistic regression model in terms of prediction accuracy. [ABSTRACT FROM AUTHOR]

Mechanical response of nano-based composites is generally influenced by interaction of filler and matrix at interface. Increasing filler-loading within the composite may cause spatial limitation toward best dispersion of filler, and since synthesizing a totally agglomerated-free nanocomposite is difficult, filler and matrix interaction needs to be perfectly modeled. A micromechanical model is developed in this study based on the common Halpin–Tsai theory to predict the elastic stiffness of vinyl ester/exfoliated graphite platelet nanocomposites. The model considers near-rational ideal (uniformly dispersed) mixed with clustered filler-network to simulate filler-distribution conditions. A filler-dispersion level based on the filler concentration has been proposed mathematically in this study. Predictions of the proposed model considering filler morphology were compared with the predictions of the Halpin–Tsai model and the experimentally obtained results as well. The proposed model shows better accuracy in terms of stiffness over predictions of the Halpin–Tsai model and appears in a very good agreement with the experimental results obtained for vinyl ester nanocomposites. [ABSTRACT FROM PUBLISHER]

Sn-Sr system is critically evaluated and the most reliable experimental data are incorporated in thermodynamic modeling. Thermodynamic properties of the binary liquid solution are estimated using the modified quasichemical model (MQM). The optimized Sn-Sr phase diagram and the corresponding thermodynamic properties are found to be in fair agreement with the experimental data in the previous related literature. For all the compounds in Sn-Sr system, a comparison between the calculated enthalpy of formation and that calculated by Miedema and first-principles has been reported. Combining Sn-Sr with the self-established thermodynamic database of Mn-Sr and Mn-Sn was used to calculate liquidus projection of Mn-Sn- Sr ternary system. [ABSTRACT FROM AUTHOR]