Electrochemical and Spectroscopic Study of Benzotriazole Films Formed on Copper, Copper-zinc Alloys and Zinc in Chloride Solution

The formation of protective layers on copper, zinc and copper-zinc (Cu-10Zn and Cu-40Zn) alloys at open circuit potential in aerated, near neutral 0.5 M NaCl solution containing benzotriazole (BTA) was studied using potentiodynamic measurements, electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). The addition of benzotriazole affects the dissolution of the materials investigated. Benzotriazole, generally known as an inhibitor of copper corrosion, is also shown to be an efficient inhibitor for copper-zinc alloys and zinc metal. The effectiveness of inhibition depending on the type of materials was compared. X-ray photoelectron spectroscopic results showed that the surface layer formed on alloys in BTA-inhibited solution comprised both oxide and polymer components. The formation of Cu2O/Cu(I)-BTA on copper, mixed oxides/Zn(II)-BTA and Cu(I)-BTA on copper-zinc alloys and ZnO/Zn(II)-BTA polymer surface film on zinc provides an effective barrier against corrosion on materials investigated in chloride solution

Efekat biouglja na morfološka svojstva kukuruza i soje

This paper analyses the effects of the biochar application morphological traits in maize and soybean under semi-controlled conditions. During the study, the increasing doses of biochar (0%, 0.5%, 1, 3, and 5%) were incorporated in three soil types: Alluvium, Humogley and Chernozem to determine plant height and shoot weight. The experiment was set up as fully randomized design with three repetitions. The plants were grown in pots of 5 l with controlled watering and N fertilization. The research results have shown that there are differences in terms of biochar effects on soils. The greatest effect on plant height and shoot weight was obtained when the biochar was applied to Humogley soil and lower effects were found on the Alluvium soil. The increase in aboveground mass of maize and soybeans was significantly conditioned by adding different doses of biochar. Based on these results, it can be concluded that adding biochar can significantly affect the growth of plants. This is a consequence of the changes it causes in soil, which requires further tests to complement the current findings.U radu je ispitivan uticaj primene biouglja na morfološka svojstva kukuruza i soje u polukontrolisanim uslovima. Primenjene su rastuće doze biouglja na tri tipa zemljišta: aluvijum, černozem i humoglej i praćena je visina biljaka i masa nadzemnog dela. Ogled je postavljen po randomiziranom rasporedu sa tri ponavljanja u sudove zapremine 5 litara, a setva je izvršena u mesecu maju. Rezultati istraživanja su pokazali da postoje razlike u pogledu ispitivanih zemljišta i primenjenih doza biouglja. Najbolji efekat je dobijen kada je biougalj primenjen na zemljište humoglej a najmanji uticaj primene biouglja je utvrđen na aluvijalnom zemljištu. Porast nadzemne mase kukuruza i soje bio je u značajnoj meri uslovljen dodavanjem različitih doza biouglja. Na osnovu dobijenih rezultata može se zaključiti da dodavanje biouglja može značajno uticati na porast biljaka koji je posledica promene koje on izaziva u svojstvima zemljišta, ali da je neophodno nastaviti dalja ispitivanja kako bi se upotpunila dosadašnja saznanja. Utvrđeno je da su ispitivana svojstva kod soje ispoljila veću reakciju na primenu biouglja u odnosu na kukuruz

Distribution and forms of iron in the vertisols of Serbia

Soil of arable land and meadows from the Ap horizon, taken from ten different localities, were investigated for different forms of Fe, including total (HF), pseudo-total (HNO3), 0.1 M HCl extractable and DTPA (diethylenetriaminepentaacetic acid)-extractable. A sequential fractional procedure was employed to separate the Fe into fractions: water soluble and exchangeable Fe (I), Fe specifically adsorbed with carbonates (II), reducibly releasable Fe in oxides (III), Fe bonded with organic matter (IV) and Fe structurally bonded in silicates (residual fraction) (V). The soil pH, cation exchange capacity, and size fractions (clay and silt) had a strongest influence on the distribution of the different forms of Fe. The different extraction methods showed similar patterns of the Fe content in arable and meadow soils. However, the DTPA iron did not correspond with the total iron, which confirms the widespread incidence of iron-deficiency in vertisols is independent of the total iron in soils. The amount of exchangeable (fraction I) and specifically adsorbed (II) iron showed no dependence on its content in the other fractions, indicating low mobility of iron in vertisols. The strong positive correlation (r = 0.812 and 0.956) between the content of iron in HNO3 and HF and its contents in the primary and secondary minerals (fraction – V) indicate a low content of plant accessible iron in the vertisol. The sequential fractional procedure was confirmed as suitable for accessing the content and availability of iron in the vertisols of Serbia

Gas nitriding and subsequent oxidation of Ti-6Al-4V alloys

Ti-6Al-4V alloys consisting of α-Ti grains and intergranular β-Ti islands were nitrided at 850°C for 1 to 12 h under a nitrogen pressure of 1 Pa. With increasing nitriding time, the Ti-N compound layer became thicker, and the α-Ti diffusion zone containing dissolved nitrogen became wider. In the Ti-N compound layer, the initially formed Ti2N became TiN as the nitriding progressed. The nitride layers were oxidized to rutile-TiO2 after oxidation at 700°C for 10 h in air

Incorporating corrosion measurement in hip wear simulators: An added complication or a necessity?

Corrosion is not routinely considered in the assessment of the degradation or the lifetime of total hip replacement bearing surfaces. Biomechanical simulations are becoming ever more complex and are taking into account motion cycles that represent activities beyond a simple walking gait at 1 Hz, marking a departure from the standard ISO BS 14242. However, the degradation is still very often referred to as wear, even though the material loss occurs due to a combination of tribological and corrosion processes and their interactions. This article evaluates how, by incorporating real-time corrosion measurements in total hip replacement simulations, pre-clinical evaluations and research studies can both yield much more information and accelerate the process towards improved implants