Gravimetric Tests Research Articles

Evaluation of anti-corrosion performance of poly(maleic acid-co-N‐[3‐(dimethylamino)propyl]‐methacrylamide) as novel copolymer inhibitor for carbon steel in neutral medium

Polymer corrosion inhibitors have many advantages in comparison with small organic molecule inhibitors, such as easier formation of multilayer films on metal surface, more adsorption sites and better temperature resistance. Poly(maleic acid-co-N‐[3‐(dimethylamino)propyl]‐methacrylamide) (PMD) was synthesized via aqueous solution polymerization and its structure and molecular weight were confirmed. The anti-corrosion performance of PMD for Q235 carbon steel in neutral medium was evaluated by several methods like gravimetric and electrochemical tests, surface analysis and theoretical calculation. Results indicated that polymer corrosion inhibitor PMD exhibited high corrosion inhibition efficiency of 90.1% at a dosage of 200 mg/L, and acted as anodic-type inhibitor that inhibited anodic reactions by forming adsorption polymer film. The adsorption model conformed to Langmuir adsorption isotherm involving both physisorption and chemisorption fitted by electrochemical data. The outcomes of surface morphology investigation including contact angle analysis, AFM and SEM were consistent with experimental results. Moreover, Theoretical calculation including quantum chemical computation and molecular dynamics (MD) simulation further reveal the corrosion inhibition mechanism of PMD.

NovelN,N‐dimethylacrylamidecopolymer containing multiple rigid comonomers as a filtrate reducer inwater‐baseddrilling fluids and mechanism study

AbstractUltra‐high temperature dramatically deteriorates rheological properties and filtration performance of water‐based drilling fluids (WBDFs), especially for a salt‐gypsum formation that greatly restricts the application of WBDFs in ultra‐deep well drilling operations. Hence, the research in this article used an anionic copolymer (DANS) prepared byN,N‐dimethylacrylamide, 2‐acrylamide‐2‐methylpropanesulfonic acid,N‐vinylpyrrolidone, and sodium 4‐styrenesulfonate as an anti‐ultra‐high temperature and anti‐salt contamination filtrate reducer. Due to its multiple bulky cyclic structures in the side chain, DANS exhibits excellent thermal stability in the thermal gravimetric, rheological, and filtration tests. By adding 1.0 wt% DANS, the American Petroleum Institute (API) filtration volume of sodium bentonite‐based fluids (SBT‐BFs) decreased from 56.0 to 9.2 ml after aging at 240°C. Even under both 20 wt% NaCl contamination and 240°C aging, SBT‐BFs with 2.0 wt% DANS could maintain a filtration volume of 9.4 ml, whereas SBT‐BFs without DANS reached a filtration volume of 203.0 ml. The possible filtration control mechanism of DANS was further investigated via the Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), ζ potential, particle size distribution, filter cake micro‐morphology, and transmission electron microscopy (TEM). Confirmed by FTIR and AFM results, the effective adsorption was formed between DANS and bentonite even under a high‐salinity environment. Thus, a firm “dot net” structure formed by bentonite/DANS was observed by TEM, significantly improving the colloidal stability, dispersibility, and filter cake compactness of SBT‐BFs. Finally, by utilizing DANS as the core treatment agent, a high‐density WBDFs system with a temperature resistance of 240°C and a salt‐tolerance of 20 wt% has been successfully prepared.

Comparison the Using of Polypropylene and Low-Density Polyethyelene Plastic Waste as a Matrix in Making Biodegradable Plastics and Starch from Empty Fruit Bunch of Palm Oil as a Filler

The using of plastic waste from various types of plastics such as polypropylene and LDPE is carried out to see the properties of each biodegradable plastic produced, so that it can be used according to their respective needs. The addition of starch from empty fruit bunch of palm oil is expected to produce biodegradable plastic that breaks down naturally so that it can overcome the problem of plastic build up. The composition used in the manufacture of biodegradable plastics is the ratio of plastic waste and starch of empty fruit bunch of palm oil is 60:40. The method of molding biodegradable plastics is the hot press method. Biodegradable plastic from LDPE type plastic waste has a tensile strength price of 6.9410 N/m 2 and a elongation value of 3.1875%, a melting point temperature of 103°C and a decomposition temperature of 384°C, the gravimetric thermal test obtained a residue of 12.6%, and analysis of morphological properties shows spread the starch from empty fruit bunch palm oil evenly. Biodegradable plastic from polypropylene type plastic waste has a tensile strength value of 9.81 N/m 2 and elongation of 0.5625%, a melting point at a temperature of 163.68°C and decomposes at a temperature of 445.62°C the gravimetric thermal test obtained a residue of 11.5%. From the resulting characteristics, it can be concluded that biodegradable plastic made from LDPE material has lower strength but higher elasticity, and biodegradable plastic made from Polypropylene has better strength but low elasticity.

Biosurfactant production and diesel-fuel removal by isolated bacteria from Kalimas Estuary, Madura Strait

This experiment was done to evaluate isolated bacteria in the production of biosurfactant and biodegradation of diesel-fuel. Diesel-fuel degrading bacteria were isolated from Kalimas Estuary, Surabaya using three-stage enrichment culture in Bushnell Haas Mineral Salts medium with 1% diesel fuel. Purified isolates were subjected to both oil-displacement and E24-emulsification tests to assess the high activity of produced biosurfactant. Selected isolates were next used in biodegradation analysis of diesel-fuel using a gravimetric total petroleum hydrocarbon test. The potential isolates were identified based on their 16S rDNA sequences. Twenty-eight purified isolates were obtained from the water samples and confirmed as gram-negative hydrocarbonoclastic bacteria. Among them, isolate K8 demonstrated the widest diameter on diesel-fuel displacement test by 3.5 cm of oil-free zone. It was also superior in emulsifying diesel-fuel with 9.4% of E24 index. Isolate K8 was capable of degrading 57% of 1 mL of diesel fuel within 14-day incubation. The isolate was potential in both producing biosurfactant and degrading diesel fuel. Isolate K8 was identified as Pseudomonas aeruginosa with 99.74% sequence similarity.

Combined steam and dry reforming of methanol over Fe‐Mn‐Cu / ZrO 2 catalyst to syngas formation: Study about kinetic and fuzzy model approaches

Combined steam and dry reforming of methanol (CSDRM) experiments were applied to measure the responses of CH3OH conversion, H2/CO ratio, H2 and CO yield at a temperature range of 300°C to 900°C, CO2/H2O ratio of 0.5 to 2.5 and (CO2 + H2O)/CH3OH ratio of 1 to 3 on Fe-Mn-Cu/ZrO2 catalyst in a fixed bed reactor. Fe-Mn-Cu/ZrO2 catalyst was synthesized via the co-precipitation approach, and its physicochemical properties were examined through X-ray diffractometer, X-ray fluorescence, temperature-programmed reduction, N2 adsorption/desorption and thermal gravimetric analysis tests. A kinetic model for CSDRM reaction was derived via the Langmuir-Freundlich method and the proposed mechanism included three reversible reactions on three types of active sites. A Mamdani-type fuzzy model was also developed for comparison purposes, as there was no need for detailed knowledge of the process. The error of the kinetic and Mamdani-type fuzzy model approaches obtained 12.69% and 16.42%, respectively. H2 yield obtained from kinetic model values was closer to the experimental data compared to other responses. However, for the fuzzy model approach, the difference between experimental and calculated methanol conversion was lower.

Enrichment and Characterization of Hydrocarbon Degrading Bacteria from Various Oil-Contaminated Sites in Pakistan

Accretion of polycyclic aromatic hydrocarbons in environment due to variety of anthropogenic activities has taken this ecosystem to the brink of destruction. Since the dawn of century, various physio-chemical methods have been postulated for the removal of these noxious substances. So far, microbial degradation is a most effective way to get rid of this ecological problem. Therefore, the assessment of randomly nominated soil samples from different sites of country land (Pakistan) was performed to scrutinize the proficiency of indigenous bacteria in degrading hydrocarbons (Hi-Octane, petrol, kerosene oil, and lubricating oil). The statistically based Plackett–Burman experimental design was also applied to evaluate the cultural conditions affecting degradation potency. Potential isolates were identified through biochemical and molecular analysis followed by the Gravimetric test to estimate the degradation level. In addition, the isolated strains exhibited a significant production of bio-surfactants in their cell-free condition. Five potent strains including Streptococcus sp., Bacillus flexus, Arthrobacter sp., Bacillus sp., and Ancyclobacter rudongensis were screened out, which have an ability to degrade and utilize kerosene oil, Hi-octane, petrol, and lubricating oil when analyzed individually. However, the bacterial consortium of all five strains (AA1-5) exhibited prodigious efficiency to degrade variety of hydrocarbons in less time.

Experimental Analysis of Corrosion Rate of Developed Nanocutting Fluid from Admixture Nanoparticles

This study is an evaluation of the performance of mild steel coupons in developed silica nanofluid from rice husk ash. Gravimetric and electrochemical measurement methods were used for the experimental work. The chemical composition of silica was confirmed by SEM/EDS graph. The gravimetric test result shows that sample F (1.00 g/L RHA) gave the lowest corrosion rate of 1.8E−05 mm/year at 168 h. It was also observed that better protection of the material was achieved with increase in exposure time, hence lower corrosion rates. From the results of electrochemical tests, there was significant change in corrosion potential and corrosion rate with change in nanofluid concentration. Corrosion rate was positively slowed down by lower concentration of silica nanofluid. Sample C (0.25 g/L RHA) revealed the lowest instantaneous corrosion rate of 0.02876 mm/year. Silica nanofluid developed from rice husk ash may be better suited for cutting mild steel than the conventional cutting fluid.

Micro Freeze-Dryer and Infrared-Based PAT: Novel Tools for Primary Drying Design Space Determination of Freeze-Drying Processes

PurposePresent (i) an infrared (IR)-based Process Analytical Technology (PAT) installed in a lab-scale freeze-dryer and (ii) a micro freeze-dryer (MicroFD®) as effective tools for freeze-drying design space calculation of the primary drying stage.MethodsThe case studies investigated are the freeze-drying of a crystalline (5% mannitol) and of an amorphous (5% sucrose) solution processed in 6R vials. The heat (Kv) and the mass (Rp) transfer coefficients were estimated: tests at 8, 13 and 26 Pa were carried out to assess the chamber pressure effect on Kv. The design space of the primary drying stage was calculated using these parameters and a well-established model-based approach. The results obtained using the proposed tools were compared to the ones in case Kv and Rp were estimated in a lab-scale unit through gravimetric tests and a thermocouple-based method, respectively.ResultsThe IR-based method allows a non-gravimetric estimation of the Kv values while with the micro freeze-dryer gravimetric tests require a very small number of vials. In both cases, the obtained values of Kv and Rp, as well as the resulting design spaces, were all in very good agreement with those obtained in a lab-scale unit through the gravimetric tests (Kv) and the thermocouple-based method (Rp).ConclusionsThe proposed tools can be effectively used for design space calculation in substitution of other well-spread methods. Their advantages are mainly the less laborious Kv estimation process and, as far as the MicroFD® is concerned, the possibility of saving time and formulation material when evaluating Rp.

Effect of Water Ingress on the Mechanical and Chemical Properties of Polybutylene Terephthalate Reinforced with Glass Fibers.

Short fiber reinforced polymers are widely used in the construction of electronic housings, where they are often exposed to harsh environmental conditions. The main purpose of this work is the in-depth study and characterization of the water uptake behavior of PBT-GF30 (polybutylene terephthalate with 30% of short glass fiber)as well as its consequent effect on the mechanical properties of the material. Further analysis was conducted to determine at which temperature range PBT-GF30 starts experiencing chemical changes. The influence of testing procedures and conditions on the evaluation of these effects was analyzed, also drawing comparisons with previous studies. The water absorption behavior was studied through gravimetric tests at 35, 70, and 130 °C. Fiber-free PBT was also studied at 35 °C for comparison purposes. The effect of water and temperature on the mechanical properties was analyzed through bulk tensile tests. The material was tested for the three temperatures in the as-supplied state (without drying or aging). Afterwards, PBT-GF30 was tested at room temperature following water immersion at the three temperatures. Chemical changes in the material were also analyzed through Fourier-transform infrared spectroscopy (FTIR). It was concluded that the water diffusion behavior is Fickian and that PBT absorbs more water than PBT-GF30 but at a slightly higher rate. However, temperature was found to have a more significant influence on the rate of water diffusion of PBT-GF30 than fiber content did. Temperature has a significant influence on the mechanical properties of the material. Humidity contributes to a slight drop in stiffness and strength, not showing a clear dependence on water uptake. This decrease in mechanical properties occurs due to the relaxation of the polymeric chain promoted by water ingress. Between 80 and 85 °C, after water immersion, the FTIR profile of the material changes, which suggests chemical changes in the PBT. The water absorption was simulated through heat transfer analogy with good results. From the developed numerical simulation, the minimum plate size to maintain the water ingress unidirectional was 30 mm, which was validated experimentally.

Quality control of cytostatic drug preparations-comparison of workflow and performance of Raman/UV and high-performance liquid chromatography coupled with diode array detection (HPLC-DAD).

The drugs used for treatment during chemotherapy are manufactured individually for each patient in specialised pharmacies. Thorough quality control to confirm the identity of the delivered active pharmaceutical ingredient and the final concentration of the prepared application solution is not standardized yet except for optical or gravimetric testing. However, solution stability problems, counterfeit drugs, and erroneous or deliberate underdosage may occur and negatively influence the quality of the product and could cause severe health risks for the patient. To take a step towards analytical quality control, an on-site analytical instrument using Raman and UV absorption spectroscopy was employed and the results were compared to high-performance liquid chromatography coupled to diode array detection. Within the scope of the technology evaluation, the uncertainty of measurement was determined for the analysis of the five frequently used cytostatic drugs 5-fluorouracil, cyclophosphamide, gemcitabine, irinotecan and paclitaxel. The Raman/UV technique (2.0-3.2% uncertainty of measurement; level of confidence: 95%) achieves a combined uncertainty of measurement comparable to HPLC-DAD (1.7-3.2% uncertainty of measurement; level of confidence: 95%) for the substances 5-fluorouracil, cyclophosphamide and gemcitabine. However, the uncertainty of measurement for the substances irinotecan and paclitaxel is three times higher when the Raman/UV technique is used. This is due to the fact that the Raman/UV technique analyses the undiluted sample; therefore, the sample has a higher viscosity and tendency to foam. Out of 136 patient-specific preparations analysed within this study, 96% had a deviation of less than 10% from the target content.

Effect of Nanoclay in the Mechanical and Thermal Behaviour of Glass Fibre Reinforced Epoxy

This work investigates the effect of nanoclay in the mechanical and thermal characteristics of GFRP laminates. The Cloisite 15A nanoclay has added to the matrix with proportion of 1%, 2% and 3% by weight. The processed nanocomposites are characterized with X-Ray Diffraction to identify the inter layer spacing of clay in the matrix. The filler added epoxy, reinforced with the unidirectional glass fibre by hand layup technique and the specimens are tested for tension, hardness, flexural and fracture loadings. Dynamical mechanical analysis and thermo gravimetric tests are also conducted to understand the visco-elastic and thermal behaviour of the material. The addition of clay in the matrix generally increases the mechanical properties up to our consideration that is 3% clay loading. Thermal and visco-elastic behaviour found consistent up to 1% clay loading and reduces the performance after that in overall sense.

Consistent modelling of material weight loss and gas release due to pyrolysis and conducting benchmark tests of the model-A case for glovebox panel materials such as polymethyl methacrylate.

It is necessary to consider how a glove box's confinement function will be lost when evaluating the amount of radioactive material leaking from a nuclear facility during a fire. In this study, we build a model that consistently explains the weight loss of glove box materials because of heat input from a flame and accompanying generation of the pyrolysis gas. The weight loss suggests thinning of the glove box housing, and the generation of pyrolysis gas suggests the possibility of fire spreading. The target was polymethyl methacrylate (PMMA), used as the glove box panel. Thermal gravimetric tests on PMMA determined the parameters to be substituted in the Arrhenius equation for predicting the weight loss in pyrolysis. The pyrolysis process of PMMA was divided into 3 stages with activation energies of 62 kJ/mol, 250 kJ/mol, and 265 kJ/mol. Furthermore, quantifying the gas composition revealed that the composition of the pyrolysis gas released from PMMA can be approximated as 100% methyl methacrylate. This result suggests that the released amount of methyl methacrylate can be estimated by the Arrhenius equation. To investigate the validity of such estimation, a sealed vessel test was performed. In this test, we observed increase of the number of gas molecules during the pyrolysis as internal pressure change of the vessel. The number of gas molecules was similar to that estimated from the Arrhenius equation, and indicated the validity of our method. Moreover, we also performed the same tests on bisphenol-A-polycarbonate (PC) for comparison. In case of PC, the number of gas molecules obtained in the vessel test was higher than the estimated value.

Carbon steel corrosion inhibition in acid medium by imidazole-based molecules: Experimental and molecular modelling approaches

This paper deals with application of imidazole (IMI) and four imidazole derivative molecules: 4-(imidazole-1-il)-phenol (PHEN), [4-(1H-imidazole-1-yl)-phenyl]methanol (METH), 2-(1H-imidazol-1-yl)-1-phenylethan-1-one (ETHAN) and 4-(1H-imidazole-1-yl)benzaldehyde (BENZ), towards corrosion inhibition of 1020 carbon steel in acidic medium. From IMI to ETHAN, the corrosion inhibition efficiency more than doubled in gravimetric experiments and increased 85% and 68% in the potentiodynamic polarization and electrochemical impedance assays, respectively. Both gravimetric and electrochemical tests gave the following decreasing order for the corrosion inhibition efficiency: BENZ > ETHAN > METH > PHEN > IMI. Quantum chemical calculations based on density functional theory (DFT) method showed that global hardness of the inhibitor molecules and inhibition efficiency were inversely proportional, which means that a softer molecule (or lower charge/radius ratio considering HSAB theory) leads to higher anticorrosion efficiency. Monte Carlo method (MC) was used to calculate the adsorption energies in a simulated water environment, and Compass force field was selected towards obtaining the solvation energy between inhibitor and metallic surface. The calculated solvation energy showed an inverse correlation between solvation energy and corrosion inhibition, having BENZ molecule lower solvation energy and lower global hardness which explains better anticorrosion efficiency among other IMI-based molecules, which shows the importance of molecule polarity over the corrosion inhibition of carbon steel.

Enhanced anti-biofouling ability of polyurethane anti-cavitation coating with ZIF-8: A comparative study of various sizes of ZIF-8 on coating

Biofouling and cavitation erosion are the key important factors causing the degradation and fatigue failure of metal materials in seawater. Herein, a series of polyurethane (PU) /ZIF-8 (PHZ) composite coatings were successfully synthesized with different sizes of ZIF-8 nanoparticles (NPs) for antifouling property combined with cavitation erosion resistance. The morphology and structure of the PHZ composite coatings were characterized by XRD, ATR-FTIR, SEM and AFM. The static water contact angle, dynamic mechanical analysis and thermo gravimetric tests further confirmed that the ZIF-8 NPs could improve the hydrophobic, mechanical and thermal properties of the PU coatings. Importantly, the effect of the ZIF-8 NPs with different sizes on the performance of the PHZ coatings was also investigated. The PHZ1 coating with the ZIF-8 NPs (~50 nm) displayed the highest static water contact angle (105°), the largest tensile strength (6.78 MPa) and the best thermal stability among these PHZ coatings. The antifouling properties of the PHZ coatings were also tested against marine diatom (Nitzschia closterium). Especially, the biofouling attachment rate of the PHZ1 coating was 0.51%, which was far less than that of pure PU coating (92%). Moreover, the mass loss of the PHZ1 coating was only 8.9 mg after cavitation test for 24 h. Notably, both antifouling and anti-cavitation properties of the PHZ coatings were inversely proportional to the particle size of the ZIF-8 NPs. The present study offers a simple and green coating technology that combines the antifouling and anti-cavitation to promote the development of ZIF/PU nanocomposite systems for practical applications.

Application of an Aqueous Extract of Cotton Seed as a Corrosion Inhibitor for Mild Steel in HCl Media

Abstract The present work aims to study the aqueous cotton seeds extract as a natural inhibitor of the corrosion of mild steel in 1 mol L−1 HCl using gravimetric tests, potentiodynamic polarization curves, electrochemical impedance measurements and surface morphological analysis by scanning electron microscopy (SEM). The aqueous cotton seed extract acted as a good corrosion inhibitor reaching an inhibition efficiency of 95.7% after 24 h of immersion for 800 mg L−1 inhibitor concentration. For the gravimetric tests varying the temperature, a decrease of the activation energy (Ea) was observed, suggesting a chemical adsorption on the surface of the metal. 400 mg L−1 of the high molecular weight fraction isolated from the total extract showed inhibition efficiency equal to 800 mg L−1 of the total extract, 97.3% and 94.2% from electrochemical impedance and polarization curves data, respectively, suggesting that the macromolecules present a fundamental participation in the inhibitive process.

Insight into the Emulsification Process Effect on Particles Distribution in Pickering Emulsions: a Series of Rheological and Gravimetric Tests

Insight into the Emulsification Process Effect on Particles Distribution in Pickering Emulsions: a Series of Rheological and Gravimetric Tests

Comparative study of diesel sorption performance between Chorisia speciosa fibers and a commercial polyurethane foam

The objective of this work was to evaluate and compare the potential of polyurethane and kapok (Chorisia speciosa) residues as sorbent materials in the treatment of diesel spillage. To determine the sorption capacity, gravimetric tests were performed in static medium at room temperature and at different temperatures (10, 15 and 28 °C) and varying the time of contact between the sorbent material and diesel. It was observed that the sorption process occurs at a high velocity, with saturation point achieved in the first 5 minutes of contact, and the natural fiber presents higher sorption capacity compared to the polyurethane residue due to the low viscosity of diesel oil, that contributes to reduce de entrapment inside the porous foam. It has also been observed that the polyurethane residue exhibits an increase in sorption capacity with time and temperature increase. Scanning electron microscopy (SEM) analysis have shown that the main morphological property involved in smooth oil sorption was the high porosity associated with a small porous diameter. The kapok presented sorption capacity of 37 g/g in equilibrium demonstrating its great potential of application as a sorbent material for the treatment of diesel spillage.

Aqueous Extract of Cumaru (Dipteryx odorata) Seeds as Corrosion Inhibitor for Mild Steel in Hydrochloric Acid Solution

The corrosion inhibition of mild steel by aqueous extract of cumaru (Dipteryx odorata) seeds and its high molecular weight fraction (HMWF) was investigated in 1 mol L-1 HCl solution. The study was carried out through gravimetric essays, open circuit potential measurements, anodic and cathodic polarization curves and electrochemical impedance analyses, as well as morphological analysis of the mild steel by scanning electron microscopy. Gravimetric tests showed that the inhibition efficiency (IE) increased with immersion time and inhibitor concentration, reaching 98% of IE using 100 mg L-1 of the HMWF, after 6 h immersion time. The activation energy (Ea) increased with the addition of both inhibitors which characterizes a physical adsorption of the constituents of the aqueous extract of cumaru on the metal surface. Polarization curves indicated that both aqueous cumaru seeds extract and its HMWF act as mixed-type inhibitor. Impedance results showed a decrease in double layer capacitance (Cdl) and an increase in charge transfer resistance (Rct) evidencing a typically screening effect. The adsorption of molecules present in the aqueous extract of cumaru followed the Langmuir isotherm. The aqueous cumaru seeds extract was characterized by Fourier transform infrared spectroscopy (FTIR), 1H, 13C and 2D nuclear magnetic resonance (NMR).

Combating A36 mild steel corrosion in 1 M H<sub>2</sub>SO<sub>4</sub> medium using watermelon seed oil inhibitor

<abstract> Corrosion inhibitive performance of the extracted watermelon seed oil on A36 mild steel in 1 M H₂SO₄ medium, at 305 and 319 K corrosion reaction temperatures, was investigated. Weight loss and inhibition efficiency were determined using gravimetric method while corrosion rate and inhibitoion efficiency were evaluated using potentiodynamic tests. Gravimetric tests showed that watermelon seed oil inhibitor attained a better corrosion inhibition efficiency of 50% at the operating temperature of 305 K compared to an efficiency of 48% obtained at the operating temperature of 319 K. Electrochemical potentiodynamic polarization tests showed that 3 vol/vol% inhibitor concentration gave the most promising corrosion inhibiting results at the operating temperature of 305 K, while 4 vol/vol% inhibitor concentration gave the most reliable corrosion resisting one at the operating temperature of 319 K. Langmuir adsorption isotherm correctly predicted the adsorption behaviour of the watermelon seed oil on A36 mild steel surface in 1 M H₂SO₄ medium. the negative values of ∆G_ads revealed the spontaneous adsorption nature of the inhibitor on the mild steel surface and the electrochemical potentiodynamic polarization results showed that the watermelon seed oil acted as a mixed-type corrosion inhibitor. The optical image analysis revealed both the potency level of watermelon seed oil as an inhibitor as well as the optimum inhibitor concentrations of 3 vol/vol% (at 305 K) and 4 vol/vol% (at 319 K). </abstract>

Methodology for studying the corrosion of material of oil pipelines operating in marshy soil

The main reason for the operation of oil pipelines is the corrosion of their materials. As a result of corrosion, the destruction of the pipeline, contributing to the leakage of oil, which pollutes the environment, accidents and disasters. The most corrosive areas are areas of high humidity, for example: swamps. In the Russian Federation, about 30 % of the transport network of oil pipelines passes through swampy soil. As the materials of oil pipelines, pipe steels are used, for example Steel of type 3 or 09Mn2Si. The article describes a method for studying the corrosion rate of pipe steels on a laboratory bench that simulates their operation in marshy soil. A comparison is made of the corrosion mechanisms of 09Mn2Si and Steel of type 3 steels in soils with a high content of hydrogen sulfide and the presence of microorganisms by empirical tests based on the above method. The results of gravimetric tests were evaluated and the conclusions were discussed.