Technological advances have provided new ways of combating corrosion. Corrosion inhibitors are one means of protection for reinforced concrete structures. The effectiveness of commercially available inhibitor for concrete has been investigated. This study focuses on the effects of benzotriazole inhibitor on ordinary concrete and high performance concrete.The strength and durability property of different dosage of specimens without and with inhibitors on ordinary concrete and high performance concrete was compared. Corrosion tests such as Alternative Current (AC) impedance, Open circuit potential, Long term Potential Resistance (LPR) sweep, Custom sweep, and Half-cell potential were also conducted and compared with ordinary and high performance concrete without and with benzotriazole inhibitor. The inhibitor shows better performance strength, durability and good corrosive resistance.

In this study, zirconium carbide (ZrC) coatings are electrodeposited on zirconium substrate by electrolysis from molten salt at 772 oC. Electro deposition is carry out at 120 and 380 mA/cm2 as electrolysis current densities. The coatings have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FTIR) methods. Corrosion resistance of coatings are investigated using potentiodynamic polarization test in a solution containing boric acid (H3BO3) and lithium hydroxide (LiOH) at pH=6.85. The production of zirconium carbide coatings has been confirmed by XRD, FTIR and EDX analysis methods. The results show that zirconium carbide coatings improve the corrosion resistance of zirconium. Moreover, the passivation zone has been expanded by ZrC coatings. The electro deposition current density shows incredible effect on electro crystallization, nanostructure and consequently corrosion resistance of ZrC coatings. As the coating electrodeposited at 120 mA/cm2 shows lower corrosion rate. Nanostructure, coherency of ZrC particles, and absence of cracks in the coating are affected this behavior of zirconium carbide coatings.

To evaluate cold resistance in wheat in laboratory and to find fast and effective methods of evaluation, nine wheat genotypes were studied in three experiments at the College of Agriculture, University of Tehran, Karaj, Iran. Genotypes consisted of four Iranian cultivars, Sabalan, Boulani, Khalij and Naz; one Russian cultivar, Bezostaya; and four Iranian accessions, 518, 583, 592 and 1255. In experiment 1, genotypes were grown in 10-cm diameter pots and after hardening in the open, their LT50s were determined in cold chamber. Their cytoplasmic membrane stability was also measured at-12°C through electrolyte leakage measurements. In experiment 2, the genotypes were grown in the field to practise hardening in winter; then plant crowns were transferred to the lab and their LT50s were determined. Water content of crowns and leaves, sugar content of crowns, and plant erectness were also measured. In experiment 3, water content of crowns and leaves of the genotypes were measured in non-hardened plants. Cytoplasmic membrane stability, crown water content and crown sugar content of plants showed significant correlations with LT50. Membrance stability had the highest correlation with LT50 (r=0.88). A high correlation was found between crown LT50 of plants taken from field and LT50 from the plants in the lab (r=0.98). It was found that plant water content reduces with cold hardening. Water content reduction was higher in resistant genotypes compared to susceptible ones. There was no significant correlation between crown and leaf water contents with LT50 in non-hardened plants. Bezostaya with LT50=-16.7°C was the most cold resistant genotype and accession 518 with LT50=-8.2°C was the most susceptible genotype, in this study.    

Havaniroz helicopters fly in all parts of dear Iran and performing missions in different weather conditions has a great impact on the parts of these types of helicopters and sometimes they cause corrosion. In this research, to reduce the amount of wear and adhesion and enhancing corrosion resistance of helicopter skid shoes, the HVOF process is used. The HVOF process is one of the most advanced spraying systems which the most important advantages of that are the very effective and uniform heating of particles due to the intense turbulence that occurs in the combustion chamber, as well as very little surface oxidation. In this article, to reduce the wear and adhesion of helicopter brake shoes, tungsten carbide coating was done on 7075 aluminum. Coating was done by thermal spraying and with the help of tungsten carbide powder, in addition to increasing the hardness and resistance of the surface, the amount of wear was reduced to a significant extent. The metallographic structure of the part after the WC86%-Co10%-Cr4% coating had high density, no oxide particles and not melted. By creating this coating, the amount of adhesion increased to 89 MPa, which is not comparable to conventional coatings. Also, the results of the hardness tests show that the microhardness measurement of the coating had a hardness of about 1300 Vickers, which indicates that this hardness is higher than other coatings in the form of plating. By using WC86%-Co10%-Cr4% coating, the amount of wear during helicopter landing at 1000 meters reached , which shows the high hardness and high quality of the coating..

In this paper, zirconium carbide (ZrC) thin films were deposited on glass and aluminum substrates using DC magnetron sputtering. It was found that different ratios of acetylene gas (C2H2, as a reactive gas) in the gas mixture of acetylene and argon (Ar, as a sputtering gas) affect the microstructural properties, corrosion behavior, and protection efficiency of ZrC thin films. X-ray diffraction (XRD) was used to characterize the microstructural properties of thin films. The corrosion behavior of thin films in a 3.5% NaCl solution was evaluated by potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS). FESEM was also employed to examine thin films' surface morphology and thickness.