Inhibition effect of famotidine towards the corrosion of C-steel in sulphuric acid Solution

The inhibition effect of  famotidine drug  towards  the corrosion of C-steel in 0.5M H2SO4 was studied using weight loss, gasometry, potentiodynamic polarization and electrochemical frequency modulation (EFM) techniques, as well as, surface examination by SEM. The inhibition mechanism of FA is based on the adsorption process forming a film barrier layer protect the steel from acid attack. The adsorption is found to obey Frundlich model. The inhibition efficiency increased by increasing inhibitor concentration and decreased with temperature. Some thermodynamic parameters for adsorption process are deduced and discussed. Keywords: C-steel, famotidine, Adsorption, Corrosion

Incidence of hip fracture in Saudi Arabia and the development of a FRAX model

Summary A prospective hospital-based survey in representative regions of Saudi Arabia determined the incidence of fractures at the hip. The hip fracture rates were used to create a FRAX® model to facilitate fracture risk assessment in Saudi Arabia. Objective This paper describes the incidence of hip fracture in the Kingdom of Saudi Arabia that was used to characterize the current and future burden of hip fracture, to develop a country-specific FRAX® tool for fracture prediction and to compare fracture probabilities with neighbouring countries. Methods During a 2-year (2017/2018) prospective survey in 15 hospitals with a defined catchment population, hip fractures in Saudi citizens were prospectively identified from hospital registers. The number of hip fractures and future burden was determined from national demography. Age- and sex-specific incidence of hip fracture and national mortality rates were incorporated into a FRAX model for Saudi Arabia. Fracture probabilities were compared with those from Kuwait and Abu Dhabi. Results The incidence of hip fracture applied nationally suggested that the estimated number of hip fractures nationwide in persons over the age of 50 years for 2015 was 2,949 and is predicted to increase nearly sevenfold to 20,328 in 2050. Hip fracture rates were comparable with estimates from Abu Dhabi and Kuwait. By contrast, probabilities of a major osteoporotic fracture or hip fracture from the age of 70 years were much lower than those seen in Abu Dhabi and Kuwait due to higher mortality estimates for Saudi Arabia. Conclusion A country-specific FRAX tool for fracture prediction has been developed for Saudi Arabia which is expected to help guide decisions about treatment

Corrosion inhibition of copper in HNO3 solution using thiophene and its derivatives

The corrosion behavior of copper in the presence of thiophene (T) and some of its derivatives [2-thiophene carboxylic acid (TC) and 2-thienyl ethanol (TE)] has been investigated in 2 M HNO3 solution using electrochemical frequency modulation (EFM), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and weight loss techniques. Polarization studies showed that these compounds act as mixed type inhibitors. EFM technique provides a new tool for electrochemical corrosion monitoring and was used as an effective method for corrosion rate determination. In EFM measurements corrosion current density was determined without prior knowledge of Tafel slopes. Inhibition efficiency of these compounds has been found to vary with concentrations of the compounds and temperature. The adsorption of these compounds on the copper surface from the acid solution has been found to obey Langmuir adsorption isotherm. The thermodynamic activation parameters of copper corrosion in 2 M HNO3 were determined and discussed. The results obtained from EFM, EIS, Tafel and weight loss measurements were in good agreement

Adsorption and inhibitive properties of sildenafil (Viagra) for zinc in hydrochloric acid solution

Sildenafil (Viagra) was investigated as corrosion inhibitor for Zn in 1 M HCl solution using chemical and electrochemical methods at 25 °C. Electrochemical results showed that this drug is efficient inhibitor for Zn in HCl and the inhibition efficiency (IE) reached to 91% at 300 ppm. The IE increases with the drug concentration and decreases with increasing temperature. The adsorption of this drug on Zn surface follows Langmuir adsorption isotherm. The polarization plots revealed that Sildenafil acts as a mixed-type inhibitor. The thermodynamic parameters of activation and adsorption were calculated and discussed. The surface morphology of the Zn specimens was evaluated using scanning electron microscope (SEM), energy dispersive X-ray (EDX), atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) techniques. Keywords: Zn, Corrosion inhibition, HCl, SEM, EDX, AFM, FTIR, Sildenafil dru

Adsorption and corrosion inhibition behavior of polyethylene glycol on α-brass alloy in nitric acid solution

The corrosion performance of α-brass in 1 M HNO3 and in the presence of polyethylene glycol (PEG) has been investigated using AC impedance spectra (EIS), potentiodynamic polarization (PP), electrochemical frequency modulation (EFM), and mass reduction (MR) techniques. The outcome data of EIS showed a rise in the resistance charge transfer (Rct) and a decrease in the capacitance double layer (Cdl). Protection efficiency (IE) of PEG has been obtained by varying the dose of the PEG and temperature. PEG adsorbed on α-brass in acidic solution follows isotherm Langmuir. The polarization curves displayed that PEG acts as a mixed-kind inhibitor. The parameters obtained from thermodynamic activation of corrosion α-brass in 1 M HNO3 were obtained and debated. The results obtained from all tests were in excellent agreement