The Effect of Temperature in Sweet Corrosion of Horizontal Multiphase Carbon Steel Pipelines

ABSTRACT The effect of temperature on sweet corrosion in carbon steel pipelines at different liquid velocities under various oil-water concentrations was studied. Carbon steel coupons were used to study the corrosion products formed. With an increase of temperature up to 60 C, corrosion rate increases. Above 60 C, protective carbonate layers were observed. At lower temperature and pressures, the corrosion rates are similar to those predicted by de Waard and Milliams. With an increase in temperature, the corrosion rate increase is more pronounced at higher pressures and is greater than the de Waard and Milliams. No maximum in the corrosion rate is seen for oil water mixtures for temperatures up to 80C. INTRODUCTION The sweet corrosion in carbon steel pipelines flowin

Malaria pigment crystals as magnetic micro-rotors: Key for high-sensitivity diagnosis

The need to develop new methods for the high-sensitivity diagnosis of malaria has initiated a global activity in medical and interdisciplinary sciences. Most of the diverse variety of emerging techniques are based on research-grade instruments, sophisticated reagent-based assays or rely on expertise. Here, we suggest an alternative optical methodology with an easy-to- use and cost-effective instrumentation based on unique properties of malaria pigment reported previously and determined quantitatively in the present study. Malaria pigment, also called hemozoin, is an insoluble microcrystalline form of heme. These crystallites show remarkable magnetic and optical anisotropy distinctly from any other components of blood. As a consequence, they can simultaneously act as magnetically driven micro-rotors and spinning polarizers in suspensions. These properties can gain importance not only in malaria diagnosis and therapies, where hemozoin is considered as drug target or immune modulator, but also in the magnetic manipulation of cells and tissues on the microscopic scale

Electrochemical Response of Proprietary Microalloyed Steels to pH and Temperature Variations in Brine Containing 0.5% CO2

The corrosion behavior of three new-generation microalloyed steels in CO2 saturated brine at different pHs and temperatures was investigated using electrochemical measurements such as linear polarization resistance (LPR), Tafel polarization, and electrochemical impedance spectroscopy (EIS), and surface analyses techniques such as scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (SEM/EDS) and x-ray diffraction (XRD) analysis. The microalloyed steels with ferrite-pearlite microstructures demonstrated better corrosion resistance than the specimen with bainitic structures. The analysis of the corroded surface revealed relative elemental changes of corrosion products revealing that the average ratio of Fe/O increased with an increase in pH but decreased with an increase in temperature. The electrochemical results indicated that the corrosion resistance of Steel C < Steel B < Steel A. The corrosion kinetics of the steels follow the empirical relation y = AxB, thus obeying the well-known Log-Log equation (Log Y = Log A + B log X) which can be used to predict long-time corrosion performance. The value of B represents the corrosion kinetics and it decreased with an increase in pH depicting corrosion deceleration but increased with temperature signifying corrosion acceleration