Weight Loss Tests Research Articles

Investigation of microbiologically influenced corrosion of low alloy steels with different Cr contents in simulated oilfield produced water

Microbiologically influenced corrosion has become a predominant cause of pipeline and equipment failure in oil and gas fields. This research examines the corrosion behavior of steels with varying chromium contents in simulated shale gas formation water environments. Weight loss testing, Scanning Electron Microscopy (SEM), Energy Dispersive x-ray Spectroscopy (EDS), Focused Ion Beam (FIB), Transmission Electron Microscopy (TEM), and x-ray Photoelectron Spectroscopy (XPS) were employed. The findings suggest that an elevated Cr content in steel results in a gradual reduction in its uniform corrosion rate in a CO2-SRB coexistence environment. This can be primarily attributed to the significant distribution of Cr content throughout the entire product film, including both biofilm and corrosion products, thereby enhancing the product film’s protectiveness. Additionally, the competitive corrosion between CO2 and SRB, as well as the influence mechanism of Cr on corrosion, were discussed.

Insights into the role of H2O2 on corrosion behavior of NiCu low alloy steel in simulated Beishan groundwater

Steel containers used for geological disposal of high-level radioactive waste will be gradually thinned or even perforated due to corrosion, which will lead to radiolysis of nuclides when they contact with infiltrated groundwater and produce H2O2. This work focused on investigating the influence of H2O2 concentration (0%, 0.001%, 0.01%, 0.1% and 1% by volume) on the corrosion behavior of NiCu low alloy steel as the candidate material for containers was comparatively studied by combining corrosion weight loss test, corrosion product analysis, morphology characterization, thermodynamic analysis and electrochemical measurements. As [H2O2] = 0.001%, H2O2 inhibited the formation of γ-FeOOH and enhanced the compactness of rust layer, which effectively blocked the migration of aggressive ions and slowed down the cathodic reduction reaction of rust, thus improving the corrosion resistance of NiCu steel. With the increase of [H2O2] (0.01%→1%), the cathodic process of NiCu steel corrosion was promoted by the increase of dissolved oxygen involved in cathodic depolarization. Meanwhile, the relative content of Fe3O4 in the rust increased, while Fe6(OH)12SO4 and Fe6(OH)12CO3 decreased obviously, which led to the loose and porous rust layer, thus accelerating the corrosion of NiCu steel.

Corrosion behaviour and mechanism of acid-resistant steel in acidic solutions with different Cl− concentrations

This study aimed to enhance the corrosion resistance of low-alloy steel in acidic solutions with varying Cl− concentrations. A new acid-resistant steel incorporating Cu and Sb was developed. Various analyses, including immersion tests under different Cl− concentrations and pH values, corrosion weight loss tests, electrochemical tests, morphological observations, and X-ray diffraction (XRD) analysis, were conducted to investigate the corrosion behaviour and mechanism. The results show that in chlorine-containing acidic environments, acid-resistant steel undergoes chemical dissolution at the anode, with hydrogen gas precipitation at the cathode. The corrosion current density is influenced mainly by the pH and immersion time. The primary corrosion products include Fe2O3, Fe3O4, α-FeOOH, γ-FeOOH, Cu, and Sb oxides, and the intensities of the diffraction peaks of Sb2O3 and Sb2O5 increase as the pH decreases. Acid resistance primarily comes from the protective effects of Sb2O3 and Sb2O5. An increase in H+ concentration promotes uniform coverage of Sb2O3 and Sb2O5. A higher H+ concentration has a greater protective effect on the corrosion product layer than does an increased Cl− concentration, although the influence of Cu cannot be ignored.

Effect of Alkyl Chain Length on the Corrosion Inhibition Performance of Imidazolium-Based Ionic Liquids for Carbon Steel in 1 M HCl Solution: Experimental Evaluation and Theoretical Analysis.

In this study, five kinds of 1-alkyl-3-methylimidazolium bromide ([CXami]Br) ionic liquids with different alkyl chain lengths (8, 10, 12, 14, and 16) were selected as inhibitors. Then, their corrosion inhibition performances for Q235 steel in 1.0 mol L-1 HCl solution were investigated via a weight loss test, polarization curve method, and surface analysis techniques. The results show that these five imidazolium-based ionic liquids are all mixed-type inhibitors, and they can be spontaneously adsorbed onto the Q235 steel surface. The adsorption process follows the Langmuir model and involves mixed physical-chemical adsorption. Theoretical calculations confirm that the increase in alkyl chain length is conducive to the imidazolium-based ionic liquids exhibiting stronger chemical bonding abilities and forming denser adsorption films. The inhibition efficiency significantly increases below the critical micelle concentration (CMC) with an increase in alkyl chain length, and the highest inhibition efficiency is 95.17% for the [C16ami]Br inhibitor at the concentration of 0.005 mM. However, above the CMC, the inhibition efficiency is minimally affected by the alkyl chain length since all ionic liquid inhibitors have reached adsorption saturation on the steel surface.

Enhanced the SRB corrosion resistance of 316L stainless steel via adjusting the addition of Cu and Ce elements

316L stainless steel (SS) is the key raw material for the preparation of high-performance oil and gas pipelines, but even 316L with excellent properties will be attacked by sulfate-reducing bacteria (SRB) corrosion. Excellent antibacterial effects have been obtained in other SS systems by doping antibacterial elements. However, the current research on the preparation of antibacterial 316L SS is not comprehensive, and the quantitative analysis of the antibacterial mechanism and doping elements is still unclear. In this paper, the SS with Cu and Ce added were prepared by vacuum induction melting. Then the homogenization treatment combined with hot rolling was used to improve the structure segregation and mechanical properties. Further, the weight loss tests and electrochemical tests were conducted to evaluate the corrosion resistance of SS, the corrosion products and morphology were analysed, and the deformation structure was characterized to clarify the corrosion mechanism of the modified SS and quantify the doping elements. The results indicate that the microstructure after homogenization is mainly austenite, and with the increase of Ce content, the Ce-rich phase segregates. The inhibitory effect of Cu on SRB can be explained by the destructive effect of Cu ions on cell membranes. On this basis, adding a low content of Ce element can increase the permeability of the SRB cell wall and further enhance the attack effect of Cu ions on the cell membrane. The corrosion behavior of alloys shows the deformation structure dependence, with crystal defects and segregation increasing the corrosion rate. The optimal addition amount of Ce is 0.18 wt%, and the strength and elongation of SS are 511.18 MPa and 108.2%, respectively.

Biodegradable composites made from maize flour filled with olive husk fibers

The development of biomaterials based on maize flour reinforced with natural fiber was studied with the aim of replacing conventional polymers of petrochemical origin and to simplify assimilated rubbish managing strategies, which reduces the pollution of the environment. In this study, several composites based on plasticized maize flour (PMF) reinforced by the olive husk flour (OHF) in a range from 10% to 40% (wt.%) have been produced with double screw extruder. 15% (wt.%) of low-density polyethylene (LDPE) and graft polyethylene combined with maleic anhydride (PE-g-MA) bonding substance at 5 (wt.%) were added to obtain high mechanical characteristics and improve blend compatibility. Scanning electron microscope (SEM) analysis showed that the fibers were well dispersed in matrix. The Fourier-transform infrared (FTIR) spectroscopy analysis revealed an increase in the absorption bands characteristic of hydroxyl groups and the anhydroglucose ring O-C stretch by raising OHF amount in composites. Thermal stabilization and density of composites increase with the percentage of fiber. For fiber weights of 10 and 40 (wt.%), the tensile strength increased as of 8.4 to 16.4 MPa and the Young modulus as of 70 to 245%, respectively. The biodegradability of samples was tested by burying them in the soil for 90 days. The weight loss test showed that the biodegradability accelerated with the increase in OHF quantity in the PMF. The latter finding was confirmed by FTIR analysis and deteriorated surface of samples examined by SEM analysis.

Construction of microstructurally controllable B/BaCrO4 particles based on droplet microfluidic technology for enhanced usability and delay precision

Tuning the microstructure of composite energetic materials is an effective way to improve charging, safety, and combustion performance. In this paper, boron (B)/barium chromate (BaCrO4) composite particles with controllable microstructure were prepared using droplet microfluidic technology (DMT). Based on the theory of droplet template self-assembly, composite particles with controllable morphology, size, and composition were prepared, revealing the regulation mechanism of the particle microstructure. The composite particles prepared using DMT exhibit a uniform distribution of characteristic elements, high circularity, smooth surface, enhanced bulk density, and excellent flow properties. The thermal decomposition characteristics, safety, and combustion properties of the samples were investigated by thermal weight loss, mechanical sensitivity, and combustion tests. Thermal weight loss and mechanical sensitivity tests showed that the samples had stable thermal decomposition properties and significantly increased mechanical stability compared to the control. The combustion test results showed that the DMT-prepared samples had a short ignition response time and significantly improved delay precision. This paper presents a straightforward method for preparing B/BaCrO4 particles with high delay accuracy, which can serve as a reference for preparing other composites.

Effect of coexistence of sulfate reducing bacteria and nitrate reducing bacteria on the under-deposit corrosion of carbon steel

The effect of sulfate reducing bacteria (SRB) and nitrate reducing bacteria (NRB) on under-deposit corrosion (UDC) of carbon steel is studied by weight loss tests, electrochemical measurements and surface analysis. The results show that SRB-induced UDC is significantly inhibited by NRB. This inhibition is attributed to the accumulation of NRB in deposits suppressing the growth of SRB, as revealed by the analysis of total accumulation number of bacteria and the characterization of bacteria-formed micro-holes indicating localized accumulation of bacteria in deposits. The suppressed SRB growth in deposits is discussed based on the NRB-induced biologically competitive exclusion and metabolite inhibition mechanisms.

Soybean and Glycine as Potential Corrosion Inhibitors for Steel in Hydrochloric Acid: Electrochemical and Morphological Studies

The potential of soybean and glycine as organic corrosion inhibitors for steel in acid solution was examined through weight loss tests and potentiodynamic polarization. Both soybean and glycine were characterized via FTIR and UV-visible. The result shows that the soybean and glycine contain isoflavone and nitrogen bonds respectively as a beneficial element in inhibiting the corrosion of steel. Corrosion tests were performed with and without the presence of soybean and glycine for 3 days of immersion in the acidic medium. Corrosion inhibition efficiency measured via electrochemical test found that both soybean and glycine give an excellent corrosion inhibition efficiency at 1.5 g/L in 0.5 M HCl up to 96% and 94% respectively. Tafel analysis reveals both inhibitors perform mixed types inhibitors which predominantly anodic inhibition. Pseudo-passivation was observed in the Tafel curve indicating the capabilities of both inhibitors to passivate the corrosion at anodic potential. Observation of the steel samples through an optical microscope shows that the corrosion of the steel surface was inhibited in the addition of soybean and glycine in HCl. The roughness of the steel surface affected by the combination of uniform and pitting corrosion was also reduced. In overall, soybean and glycine exhibit excellent anticorrosive properties due to the presence of significant chemical structures and active functional groups. Analysis of the inhibition mechanism through isotherm showed that soybean and glycine followed Langmuir isotherm, indicating the adsorption type for both inhibitors is chemisorption. The results obtained from this study could be a good reference in diversifying the study of amino acids as metal corrosion inhibitors to benefit metal-based industries.

Inhibition Effect of Triphenylmethane Dyes for the Corrosion of Carbon Steel in CO2-Saturated NaCl Corrosion Medium.

Carbon dioxide corrosion presents a significant challenge in the oil and gas field. This study simulates the corrosive environment characteristics of oil and gas fields to investigate the corrosion inhibition properties of three triphenylmethane dyes. The inhibitive performance and mechanisms of these dyes were analyzed through weight loss and electrochemical testing, revealing that crystal violet (CV) exhibited a superior inhibition effectiveness over malachite green (MG) and Fuchsine basic (FB). At a concentration of 150 ppm in a CO2-saturated 5% NaCl solution at 25 °C, CV achieved an impressive maximum inhibition efficiency of 94.89%. With the increase in temperature, the corrosion rate slightly decreased, and the corrosion rate was 92.94% at 60 °C. The investigated CV acted as a mixed-type corrosion inhibitor and its protection obeyed the Langmuir adsorption isotherm. The corrosion morphology was characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and confocal laser scanning microscopy (CLMS). Quantum chemical calculations and molecular dynamics simulations were employed to validate the corrosion inhibition mechanisms, providing guidance for the further application of these dyes in corrosion control.

Potential of a Charcoal Evaporative Cooling Chamber for Extending the Shelf Life of Vegetables


 
 
 There are wide varieties of vegetables in Sri Lanka. The ambient temperature and relative humidity have an impact on rate of vegetables deteriorate. Evaporative cooling is a well-known, cost- effective way to reduce postharvest lost in order to lower the temperature and increase the relative humidity. This research was done to create a charcoal cooling chamber for increase the shelf life of vegetables combining polythene packaging and active packaging additives. The study was carried out in wet zone, Sri Lanka with a sizable chamber made of coconut shell charcoal. A rectangular box made of chicken wire with a 1 m3 capacity serves as the evaporative cooling chamber. It made of chicken wire mesh with a hardwood frame. The walls filled with 50 mm thick coconut shell charcoal and a water outflow 8.33 ml/min for wetting the walls. Vegetable samples without any treatment were placed in the charcoal chamber along with vegetables wrapped in sealed polyethylene (gauge 300) with and without active packing components. With a control sample held in ambient settings, the treatments were put to the test four times over the course of nine days. Both unloading and loading situations were used to evaluate the performance of chamber. Temperature drops of 4° C on average and 2.07° C on average, respectively, were seen in dry and wet climate conditions. 92.49% on average was the cooling efficiency. Sealed polyethylene bags without active packaging components were found to be the best treatment when taking into account physiological weight loss and sensory tests. When compared to the control group on days 3, 6 and 9 physiological weight loss was considerably (P<0.05) less in the sealed polyethylene bags without active packing components. When compared to the control sample total soluble solid content less in sealed polythene bag. The sensory evaluation for the treatments inside the chamber was more acceptable than for the control. Vegetables can store fresh for up to three days in evaporative cooling chamber without packaging. These chambers can install vegetable stalls on the side of the roads in Sri Lanka for temporary purposes.
 Keywords: Charcoal, Evaporation, Shelf-life, Temperature, Vegetables
 
 

Chemical, electrochemical, and surface studies of Rosa damascene extract as a green corrosion inhibitor for carbon steel in sulfuric acid environment

AbstractTo develop an environmentally acceptable corrosion inhibitor Rosa damascene extract (RD) served as the main ingredient in H2SO4 pickling processes. X‐ray photoelectron spectroscopy (XPS), Fourier‐transform infrared spectroscopy (FT‐IR), technique of electrochemical impedance spectroscopy (EIS), polarization (PP) curves, and tests of weight loss (WL) have all been utilized to examine the inhibitory behavior of Rosa damascene on C‐steel corrosion in 1 M H2SO4 environment. The results show that the extract effectively inhibited the Zn′ corrosion in 1 M H2SO4. The inhibition was more effective at higher concentrations and temperatures. The inhibitory efficiency increased to 93.5% at a higher applied temperature (45°C) and higher Rosa damascene concentration (300 ppm). However, utilizing the weight loss method at potassium iodide addition, the inhibitory effectiveness of 300 ppm of Rosa damascene was synergistically increased from 75.0% to 96.1% at 25°C. Temkin isotherm was congruent with the adsorption process that produced the inhibitory impact on the C‐steel. The chemical adhesion of the Rosa damascene extract to the surface of the C‐steel was determined by the free energy of adsorption (ΔGoads = 40.5 kJ/mol.). In H2SO4 solution, corrosion of C‐steel may be prevented by the powerful inhibitor Rosa damascene extract.

Effect of organic component (tartrate) addition on cerium nitrate's ability to inhibit corrosion of mild steel in NaCl solution

Cerium tartrate (CeTar), produced in this study by precipitating cerium nitrate with potassium sodium tartrate (KNaTar), was examined as a corrosion inhibitor. Weight loss tests show inhibition efficiency of 71.7% with Ce(NO3)3 and 88.7% with CeTar inhibitor for one-month exposure to mild steel in 7 g/L NaCl solution. The inhibition efficiency drops to 28.6% with the former and remains around 87% with the latter inhibitor after six months of exposure. Similar results from electrochemical testing indicate that the inhibition efficiency decreases by adding cerium nitrate. Still, the cerium tartrate inhibitor demonstrates a nearly constant inhibition efficiency for up to 30 d, i.e., ≈90%. Electrochemical impedance spectroscopy (EIS) performed in these cases shows the following results: (i) with cerium nitrate, a film of iron and cerium oxide, which on prolonged exposure diminishes, and (ii) with cerium tartrate, the formation of a bimetallic film (Fe-tartrate-Ce) and a mixture of cerium hydroxide and iron oxide that protects steel for a longer duration. These inferences are based on the analyses of scanning electron microscopy/energy-dispersive X-ray analysis (SEM/EDAX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron (XPS), and Raman spectroscopy results.

The synergistic effects of texture and continuous precipitates on the corrosion resistance of AZ80 magnesium alloy

The corrosion resistance of the as-forged and as-aged AZ80 alloy was analyzed through immersion tests, electrochemical measurements, and observation of corrosion morphology. The synergistic effects of texture and continuous Mg17Al12 precipitates on the corrosion behavior were investigated in this study. The results obtained from hydrogen evolution, weight loss, and electrochemistry tests showed that texture plays a more significant role in improving the corrosion resistance than continuous precipitates. However, continuous precipitates can further enhance corrosion resistance. The corrosion surface containing a single (10−10) plane texture exhibits excellent corrosion performance than that with a mixture texture composing of (0001) and (10−10) texture. Continuous precipitates that are parallel to the corrosion surface are more conducive to forming excellent corrosion barriers. Consequently, their effect on improving corrosion performance is more significant than those that are perpendicular to the corrosion surface. Exerting the synergistic effects of texture and continuous precipitates is a promising approach to improve the corrosion resistance of the AZ80 alloy.

Atmospheric corrosion acceleration effect on commercial aluminum alloys in current-carrying condition

PurposeThe purpose of this paper is to study the effect of current-carrying condition on the electrochemical process and atmospheric corrosion behavior of the commercial aluminum alloys.Design/methodology/approachPotentiodynamic polarization tests were performed to study the electrochemical process of the aluminum alloys. Salt spray tests and weight loss tests were carried out to study the atmospheric corrosion behavior. The corrosion morphology of the alloys was observed, and the products were analyzed.FindingsThe corrosion process of four aluminum alloys was accelerated in the current-carrying condition. Moreover, the acceleration effect on A2024 and A7075 was much stronger than that on A1050 and A5052. The main factors would be the differences in microstructure and corrosion resistance between these alloys. As the carried current increased, the corrosion rate and corrosion current density of the aluminum alloys gradually increased, with the protection of the corrosion product film decreasing linearly.Originality/valueThis is a recent study on the corrosion behavior of conductors under current-carrying condition, which truly understands the corrosion status of power grid materials. Relevant results provide support for the corrosion protection and safe service of aluminum alloy in power systems.

Differences between Using Mortars and Solutions When Testing Sodium Silicate as Corrosion Inhibitor for Construction Steel

Corrosion inhibitors are regularly used to minimize corrosion progress in reinforced concrete. Nitrite ions are very effective inorganic inhibitors but not environmentally friendly, since they can leach and contaminate the surrounding soil and water [1, 2]. Among other promising inorganic ions, silicate ions are of particular interest due to their low cost and low toxicity, although most results have been reported in pore simulating solutions. There is little information in the literature where silicate ions are evaluated as corrosion inhibitors in mortar or cement pastes. The purpose of this study is to show some contrasts between the effectiveness of silicate ions as carbon steel inhibitors when they are tested in solution or in mortar.The results in solution (ASCl) were obtained in an alkaline electrolyte (pH=13) that simulates good quality concrete contaminated with chloride ions [3,4]. ASCl contains KOH 0.08 mol/L, NaOH 0.02 mol/L, Ca(OH)2 0.001 mol/L and NaCl 0.3 mol/L, so that [Cl-]/[OH-]=3. The solution containing silicate ions (SSCl) incorporates Na2SiO3.5H2O 0.3 mol/L, corresponding to [inhibitor]/[Cl-]=1. The electrochemical evaluation included standard tests such as cyclic voltammograms, polarization curves, electrochemical impedance spectroscopy (EIS) and weight loss tests involving long exposure times. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy were used to investigate the composition of the surface films. The findings for bare rebars demonstrate that the presence of silicate ions in solution may effectively prevent carbon steel corrosion, with an inhibition efficiency greater than 99% and no localized attack seen after 30 days of immersion. It has also been observed that a 24-hour pretreatment at open circuit potential (OCP) in silicate solutions (SS) improves the corrosion resistance of construction steel when tested in SSCl. The polarization curves show higher pitting potential and lower corrosion current intensities when compared to untreated electrodes. XPS spectra show that silicate ions are incorporated into the surface film. Pretreatments in SS produce passive films that are rich in Fe(II), present mainly as oxohydroxides. EIS shows that the film is more resistive and compact. In contrast, the reference pretreatment in the absence of silicates led to surface films composed mainly of Fe(III) oxides and oxohydroxoxides.Tests in mortars were carried out including reinforcement bars (rebars) in mortar prepared with water/Portland cement=0.6 and sand/cement ratio =3. Mix R (for reference) had no admixed inhibitor and mix S incorporated Na2SiO3.5H2O using a 0.3 mol/L solution to replace the water in the mix. Also, samples P contained rebars pre-treated by previous immersion in silicate ions solutions, in mortars with the same composition as mix R. Once cured for 7 days, the mortar samples were immersed in aerated 0.3 mol/L NaCl solution for 3 months. The electrochemical follow-up included periodical evaluation by EIS and Rp. The alkaline reservoir in the mortar (which is the content of insoluble Ca(OH)2) was investigated by thermogravimetric analysis. Also, a lixiviation test was designed using pH indicators to verify changes in basicity after a lixiviation process. In mortars R and S, charge transfer and polarization resistance (Rt and Rp) remained lower than 50 kΩ cm2 after the first 15 days. However, Rt and Rp higher 100 kΩ cm2 were measured for rebars P after 15 and 60 days of exposure. The differences between P and R tend to flatten after 90 days of exposure. This shows that the inhibitor effect of pretreating the rebars (P) is lost over a longer period of time. According to the results from thermogravimetric tests, silicate ions in mortar consume Ca+2 ions, producing NaOH. Since this is more soluble than Ca(OH)2 it lixiviates quicker, causing the pH to decrease. Lixiviation tests support this theory.In summary, silicate ions are very effective corrosion inhibitors when tested in alkaline solutions. When silicates are used to pretreat the rebars the beneficial effect is lost after 90 days. When solutions containing silicate ions replace water in the mortars´ preparation, the inhibitory effect is lost faster due to the consumption of portlandite and the consequent acidification of the mortars.References Gaidis, J.M., Chemistry of corrosion inhibitors. Cement & Concrete Composites, 2004. 26(3): p. 181. Elsener B., Corrosion inhibitors for steel in concrete. State of the art report. London, ed. M. Publishing. 2001. Montes, F., et al., Silicate Ions as Corrosion Inhibitors for Carbon Steel in Chloride-Contaminated Concrete Pore Simulating Solutions. Corrosion, 2020. 76(12): p. 1147-1154.Rolandi A.C. et al. Corrosion Engineering, Science and Technology 57(5) (2022) 455–463. Figure 1

The effect of multi-directional compression on mechanical properties and corrosion properties of Cu–Fe composite

Cu–Fe composite is a promising candidate for electromagnetic shielding material, while it exhibits poor corrosion resistance due to the different corrosion potential of Fe particles and Cu matrix. In this study, a Cu–Fe composite was processed by multi-directional compression. The effect of multi-directional compression on the mechanical properties of the Cu–Fe composite was evaluated by the tensile test, and the effect of multi-directional compression on the corrosion properties was evaluated by the weight loss test and electrochemical measurement. After 12 compression passes, the yield strength of the Cu–Fe composite is more than two times higher than that of the initial state, and the corrosion rate decreases to nearly half compared to the initial state. Microstructure examination reveals that high density of twin boundaries were generated by multi-directional compression, which could effectively refine the grain size of Cu matrix and improve the strength of Cu–Fe composite. In addition, twin boundaries would reduce the Volta potential difference between Cu matrix and Fe particles, which could effectively inhibit galvanic corrosion, finally leading to a high corrosion resistance of the Cu–Fe composite.

Exploring rutinoside's impact on inflammation in a rat knee OA model induced by monosodium iodoacetate (MIA)

Link of Video Abstract: https://youtu.be/Dl8sYvPfd6o Introduction: Osteoarthritis (OA) is a common joint disease characterized by persistent inflammation and cartilage breakdown. Monosodium iodoacetate (MIA) is often used to generate OA in rats. This study aims to explore the anti-inflammatory benefits of rutinoside, a natural flavonoid glycoside, in rats with MIA-induced knee OA. Methods: The male Wistar rats were divided into five groups (n = 6) and randomly allocated to one of five treatments: control, OA, rutinoside, glucosamine sulfate, and sodium diclofenac-treated group. 3 mg of monosodium iodoacetate (MIA) was injected intra-articularly into the knee joints of rats to induce osteoarthritis. Rutinoside, glucosamine sulfate, and sodium diclofenac were given daily for four weeks. Body weight, joint swelling, knee bend score, interleukin-1 (IL-1) levels, interleukin-8 (IL-8) levels, and C-terminal telopeptide type II collagen (CTX-II) levels were all assessed. Result: Rutinoside significantly decreased body weight loss, joint edema, and knee bend test scores compared to the untreated OA group. Furthermore, rutinoside was equally effective as glucosamine sulfate and sodium diclofenac in these parameters. The rutinoside, glucosamine sulfate, and sodium diclofenac groups had significantly lower IL-1, IL-8, and CTX-II levels than the untreated OA group. Conclusion: Rutinoside reduced inflammatory responses, lowered joint edema, and improved knee bend test scores in a rat model of MIA-induced osteoarthritis. Its efficacy in preventing illness was comparable to glucosamine sulfate and sodium diclofenac. More study is needed to better understand rutinoside's underlying mechanisms and long-term consequences for treating osteoarthritis.

Expired terazosin as environmentally safe corrosion inhibitor for 1018 carbon steel in 1 M HCl solution: Experimental and computational studies

The corrosion inhibition performance of expired terazosin as an environmentally safe corrosion inhibitor in aqueous 1 M HCl solution for 1018 Carbon steel (CS) was assessed with coupons weight measurement (WL), combined with techniques of electrochemical (electrochemical impedance spectroscopy (EIS) and Potentiodynamic polarization). Through weight loss and electrochemical tests, the corrosion inhibition effect of expired terazosin against CS in an acidic solution was investigated. The weight loss approach at 150 ppm at 25 °C resulted in the highest inhibition efficiency (%IE) reach to 94.8 %. Potentiodynamic polarization findings indicate that this study investigated terazosin ability to behave as a mixed-type inhibitor. Nyquist diagrams showed that as the dose increased, the charge transfer resistance increased and the capacitance of the double layer decreased. It was discovered that the inhibition process conforms to the Langmuir isotherm, demonstrating that a monolayer was formed on the CS surface. Quantum chemical analysis and the Monte Carlo simulation can support the inhibitory mechanism. Theoretical estimates sustain the experimental result. This proves that the use of Expired Terazosin is a good impediment to the corroding of CS in HCl solvent.

Exploring the mechanisms of eco-friendly pyridinium ionic liquids for corrosion inhibition of carbon steel in saline mediums: Unveiling deeper understanding through experimental and computational approaches

Addressing the ongoing issue of carbon steel corrosion, this study evaluates the corrosion inhibition performance of two eco-friendly pyridinium-based ionic liquids, 4-(dimethylamino)-1-nonylpyridin-1-ium Bromide (4DMN) and 4-(dimethylamino)-1-(prop-2-yn-1-yl)pyridin-1-ium Iodide (4DMP), in a 3.5 wt% NaCl solution. Weight loss tests, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), quantum chemical calculations (QCCs), and molecular dynamics (MD) simulations were employed to carried out experimental and theoretical studies. Both 4DMN and 4DMP showed concentration-dependent inhibitory effects with 94 % and 92 % effectiveness, respectively. Potentiodynamic data showed that these compounds control both anodic and cathodic reactions without changing the corrosion mechanism. EIS results indicated a decrease in double-layer capacitance, suggesting adsorption of IL molecules on steel surface. Over a 60-h period, 4DMN maintained its effectiveness, although it decreased at higher temperatures. Surface analyses using Field Emission Scanning Electron Microscopy (FE-SEM) and Atomic Force Microscopy (AFM) showed improvements in surface morphology and roughness. Computational studies supported these findings, showing the reactivity and adsorption patterns of the ILs on the Fe (110) surface. Overall, this study contributes to understanding how pyridinium-based ILs can be used for effective and sustainable corrosion control.