Effect of acid proticity on the thermodynamic parameters of charge transfer resistance in corrosion and passivation of nickel based glass alloy.

The effect of temperature on electrochemical properties of Ni82.3Cr7Fe3Si4.5B3.2 glassy alloy in different acid proticity has been investigated utilizing AC and DC methods. Firstly, the handling of experimental data on the temperature dependence of charge transfer resistance, as well as corrosion current density permits us to determine the values of classical Arrhenius parameters as well as the thermodynamic ones considered approximately independent of temperature. This leads us to deduce a global interpretation on the phenomenon of corrosion and polarization. Secondly, the deviation to the linearity of the Arrhenius behavior and the real dependence on temperature of the thermodynamic parameters, permit us to clearly quantify the effect of the acid proticity and define, for the first time, the concept of current Arrhenius parameters and the current thermodynamic ones, as well as the modeling of the enthalpy-enthalpy compensation. Moreover, the effect of temperature can be investigated using the Vogel-Fulcher-Tammann model to reveal that the corresponding Vogel temperature has an interesting physical meaning.

On the pseudo-hyperbolic behavior of charge transfer resistance-temperature dependence in corrosion behavior of Nickel based glass alloy.

Temperature plays an important role in promoting the corrosion of metals. The Arrhenius plot can interpret the corrosion rate-temperature dependence, where the Arrhenius behavior gives a geometrical meaning and makes explicit a positive or negative linear dependence of charge transitivity and temperature. In addition, according to the Arrhenius interpretation, it represents the energy that the molecule in the initial state of the process must acquire before it can take part in the reaction, whether it is a physical, or a chemical process. Taking into account the deviation from the linearity, we have extended the Arrhenius-type expression by one term in 1/T2 and we have given some physical meaning to the new related coefficients for which it is found that they depend closely on the number of acid hydrogen atoms in the polyacid for the corrosion and passivation of the Nickel based metallic glass alloy of the composition Ni82.3Cr7Fe3Si4.5B3.2. Moreover, we can consider that the deviation to the Arrhenius linear behavior as a super-Arrhenius behavior In addition, a mathematical analysis of the trend of experimental scatter points of the charge transfer resistance with temperature permits us to reveal an interesting homographic behavior which leads us to suggest an original empirical model with only two optimal adjustable parameters, as well as a new pseudo-power dependence of the number of hydrogen atoms in the polyacid.

Empirical Modeling of COVID-19 Evolution with High/Direct Impact on Public Health and Risk Assessment.

This report develops a conceivable mathematical model for the transmission and spread of COVID-19 in Romania. Understanding the early spread dynamics of the infection and evaluating the effectiveness of control measures in the first wave of infection is crucial for assessing and evaluating the potential for sustained transmission occurring in the second wave. The main aim of the study was to emphasize the impact of control measures and the rate of case detection in slowing the spread of the disease. Non pharmaceutical control interventions include government actions, public reactions, and other measures. The methodology consists of an empirical model, taking into consideration the generic framework of the Stockholm Environment Institute (SEI) Epidemic-Macroeconomic Model, and incorporates the effect of interventions through a multivalued parameter, a stepwise constant varying during different phases of the interventions designed to capture their impact on the model. The model is mathematically consistent and presents various simulation results using best-estimated parameter values. The model can be easily updated later in response to real-world alterations, for example, the easing of restrictions. We hope that our simulation results may guide local authorities to make timely, correct decisions for public health and risk assessment.

Kinetic Modeling for Photo-Assisted Penicillin G Degradation of (Mn0.5Zn0.5)[CdxFe2-x]O4 (x ≤ 0.05) Nanospinel Ferrites.

Penicillin G is an old and widely used antibiotic. Its persistence in the environment started to appear in many environmental samples and food chains. The removal of these emerging pollutants has been a challenging task for scientists in the last decades. The photocatalytic properties of Cd2+ doped Manganese- Zinc NSFs with chemical formula (Mn0.5Zn0.5)[CdxFe2-x]O4 (0.0 ≤ x ≤ 0.05) NSFs are herein evaluated. The Manganese- Zinc N.S.F.s nanomaterials were deeply characterized, utilizing UV-Vis (reflectance) spectroscopy, X-ray diffraction, N2 adsorption isotherm measurements, and S.E.M., SEM-EDX mapping, and T.E.M. The Kinetic model for the photodegradation of penicillin G (as a model molecule) is investigated using visible light as a source of energy. The kinetic study shows that our results fit well with the modified pseudo-first-order model. The Pen G degradation are 88.73%, 66.65%, 44.70%, 37.62% and 24.68% for x = 0.5, 0.4, 0.3, 0.2 and 0.1, respectively, against 14.68% for the free Cd spinel sample. The pseudo-rate constant is bandgap dependent. From the intra-diffusion rate constant (Kd), we developed an intra-diffusion time (τ) model, which decreases exponentially as a function of (x) and mainly shows the existence of three different domains versus cadmium coordination in spinel ferrite samples. Hence, Cadmium's presence generates spontaneous polarization with a strong opportunity to monitor the charge separation and then open the route to a new generation of "assisted" photocatalysts under visible light.

Modeling of the irradiation effect on some physicochemical properties of metoprolol tartrate for safe medical uses.

The effect of gamma-irradiation and ionizing radiation (high-energy electrons beam) on the physicochemical properties of metoprolol tartrate at the solid phase and aqueous solution, has been investigated in the present study to model some properties affected by absorbed doses and to reveal some interesting mutual causal correlation. The proposed some interesting models can be adapted to other experimental conditions, and the newly obtained values of the adjustable parameters could be an excellent criterion of the state quality of the metoprolol tartrate or for other additional interpretations. The peculiar behaviour of variation of physicochemical properties against dose leads us to confirm the suggested optimized doses mentioned in previous work, for sterilization and safe medical uses.