Papers by Keyword: Acid

Abstract: Researchers continue to be concerned about corrosion of materials, which motivates them to start projects to address the harmful impacts of this phenomena that affects the desired function of our materials, especially in industries where acid is used in the process of cleaning machines. The purpose of this study is to reduce the corrosion rate of brass in 5M solution of H₂SO₄ acid using orange juice as inhibitor. The study was conducted using weight loss method. It was observed that for 24 hours the corrosion rate was higher for acid and decreased as the inhibitor was added. In all samples the corrosion rate decreases as the inhibitor were added, however improves over time. For 24 hours the efficiency was higher for acid + 100mil at 14% and it became constant after 48hrs at 32,7%. However, for 72 – 96 hours acid + inhibitor of 60mil there efficiency reported to be 54.3 and 56.4%. Keywords-orange juice, inhibitor, corrosion, acid, efficiency.

Abstract: Maize husk (MH) particulates at wt.% composition of 5% and 10%, and particle sizes of 150 and 300 um were added to the microstructure of 1170 aluminium alloy (Al) and analysed for their effect on the corrosion resistance of the maize husk reinforced aluminium composites Al/MH in 3.5% NaCl, 0.00625 M H₂SO₄ and 3.5% NaCl/0.00625 M H₂SO₄ solution by weight loss method. Protection performance results obtained at 264 h of exposure shows the MH particulates significantly enhanced the corrosion resistance of the Al/MH at 5 wt.% comp./150 um particle size (45%) and 5% wt./300 um particle size (30%) in 3.5% NaCl solution at 264 h. In 0.00625% H₂SO₄ solution, MH particulates significantly weakened the corrosion resistance of the Al/MH composites at all MH wt.% comp./particle sizes. Protection performance data at 264 h varied from-58.77% to 8.77 % which are significantly below the threshold 20% protection performance values. However, in 3.5% NaCl/0.00625% H₂SO₄, protection performance data above 20% threshold was obtained for Al/MH composites at 10% wt. comp./300 um particle size, 5% wt. comp./150 um particle size and 10% wt. comp./300 um particle sizes (22.58%, 38.71% and 29.03%). Results from ANOVA statistical method shows MH particulate wt.% comp./particle size is the important determinant factors influencing the protection performance results of Al/MH composites compared to exposure time with statistical relevance factor values of 36.53%, 77.98% and 18% from the electrolytes. The proportion of data above 20% protection performance for CB and CS particulates in 3.5% NaCl solution is 0% at margins of error of 0%. The corresponding values in 0.05 M H₂SO₄ solution are 15.18% and 15.32% at margins of error of 40% and 43% while the values from 3.5% NaCl/0.05 M H₂SO₄ solution are 14.78% and 15.5% at margins of error of 35% and 50%. The proportion of data above 20% protection performance for Al/MH composite in 3.5% NaCl solution is 30% at margins of error of 14.2%. The corresponding values in 0.00625 M H₂SO₄ solution are 15% at margins of error of 15.42% while the values from 3.5% NaCl/0.00625 M H₂SO₄ solution are 63% at margins of error of 15%.

Abstract: Particulates of cow bone (CB) and coconut shell (CS) were infused within the microstructure of 1170 aluminium alloy and studied for their influence on the corrosion resistance of the resulting aluminium matrix composites in 3.5% NaCl, 0.05 M H₂SO₄ and 3.5% NaCl/0.05 M H₂SO₄ solution by weight loss method. Corrosion rate data shows CB and CS significantly influenced the electrochemical properties of the composite. Protection performance data at 336 h of exposure shows CB and CS particulate significantly reduced the corrosion resistance of the aluminium alloy at all weight compositions in 3.5% NaCl solution. In 0.05% H₂SO₄ solution, CB improved the corrosion resistance of the composite at 5% - 15% weight composition (37.8%, 23.22% and 23.22%), while CS improved the corrosion resistance at 10% and 20% weight composition (37.65% and 28.52%). The corresponding values for CB in 3.5% NaCl/0.05 M H₂SO₄ solution occurred at 5% - 15% weight composition (34.26, 31.71% and 22.68%) while for CS it occurred at 10 and 15% weight composition (40.52% and 46.05%). Data from ANOVA statistical tool shows particulate weight composition and exposure time are both relevant determinant variables (greater than the theoretical significance factor) influencing the protection performance outputs of CB and CS with values ranging between 41.82% to 92.5% for weight composition and 5.68% and 53.03% for exposure time. Standard deviation data for CB particulate varied minimally only at 20% weight composition in 3.5% NaCl solution. The corresponding data at other CB weight compositions and for coconut shell at all weight compositions varied significantly due to thermodynamic instability.In 0.05 M H₂SO₄ and 3.5% NaCl/0.05 M H₂SO₄ solutions, all standard deviation values for CB and CS particulates (excluding CB at 29% weight composition) at all weight compositions vary minimally from the mean data signifying thermodynamic stability of the electrochemical reactions on the composite surfaces with respect to exposure time. The proportion of data above 20% protection performance for CB and CS particulates in 3.5% NaCl solution is 0% at margins of error of 0%. The corresponding values in 0.05 M H₂SO₄ solution are 15.18% and 15.32% at margins of error of 40% and 43% while the values from 3.5% NaCl/0.05 M H₂SO₄ solution are 14.78% and 15.5% at margins of error of 35% and 50%.

Abstract: The worldwide need for lightweight, high-quality, high-performance, and low-cost materials is prompting a change in emphasis from unreinforced materials to reinforced/composite materials. The mechanical properties of the MHP reinforced aluminum composite are compared to those of the unreinforced metal using the data on the corrosion performance of maize husk particulate reinforcement on high 1170 Aluminium alloy in 0.00625 M H2SO4, 3.5 wt.% NaCl and a mixture of both solutions was studied using weight loss technique to determine the corrosion rates of the specimens. Optical microscopic analysis was also carried out on the specimens to determine the effect of the reinforcement on the microstructural properties of the material before and after corrosion. The corrosion rates calculated from the weight loss study revealed differences in the corrosion characteristics of the specimens in the various solutions when compared to the control specimen. The presence of reinforcement in the matrix was discovered to positively impact the corrosion behavior of composite materials via the production of corrosion resistant oxides. The electrochemical properties of maize husk enhances the corrosion resistance of the composite due to its ability to form a protective oxide film and chemically resistant inclusions on the surface of the material.

Abstract: Analysis and description of inhibition efficiency results for tea tree and grapefruit essential oil extracts (TTGP) on mild steel (MS) and alloy steel 3310 (AS3310) in 0.5 M H2SO4 solution was done. The results show TTGP performed effectively on MS at 2% to 3.5% TTGP concentration with final inhibition values of 71.70%, 79.25%, 83.58% and 92.45% at 240 h of exposure. Inhibition efficiency generally increased with TTGP concentration and exposure time, although inhibition efficiency at 2.5% 3% TTGP concentration decreased with exposure time. Effective TTGP inhibition performance on AS3310 occurred at 3% and 3.5% TTGP concentration only with final values of 72.50% and 73.25%. Inhibition efficiency of TTGP on AS3310 varied non-proportionately with its concentration. With respect to exposure time, inhibition efficiency of TTGP on AS3310 at all concentrations decreased. Results from ANOVA analysis shows TTGP concentration significantly influenced the performance output of TTGP extract with statistically significant factor of 85.73% and 84.78% (MS and AS3310). The corresponding values for exposure time, though determined to be statistically relevant is overwhelmingly far below the influence of exposure time at values of 4.63 and 14.27. Standard deviation data shows inhibition efficiency of TTGP on MS varied minimally from mean values at all concentrations (excluding 1.5% and 2% TTGP concentration). The corresponding values for TTGP on AS3310 were also generally low at all concentrations signifying stable inhibition performance. Data showed 48% and 18% of MS and AS3310 inhibition efficiency results are greater than 80% effective inhibition performance threshold at margins of error of 12.64% and 10%

Abstract: The search for optimal conditions for the method of synthesis of copper (II) salts to create a unified one-step method for obtaining salts from natural raw materials was the purpose of this work. During the process of salt production, it is desirable that the product accumulates in the solid phase and is easily separated by phase separation methods. The study of the direct interaction of copper (II) oxide with acids in organic liquid media using a bead mill as a reactor and grinding agent of different nature showed that besides the usual places of localization of product that take place in practice, we can meet unusual places of localization of product, such as the surface of a foreign solid phase in the reactor zone, for example, the surface of the grinding agent, reactor elements, etc. It was found that in some cases, localization on a solid surface could be a favorable localization option in terms of the speed of the process. But it happens not always, because it requires specific methods of separation of film from surface, which can be very expensive. Often, the localization of the product on the solid surfaces is an extremely unfavorable localization option. It was found that different variants of product localization of interaction CuO with acids which were implemented in different proportions, prevented the creation of a unified method for producing salts in such systems

Abstract: The fibrillation mechanism of insulin in acid solution has been studied by small angle X-ray scattering (SAXS). It was observed that insulin monomer unfolded in both conditions. Furthermore, in zinc free solution, insulin tend to aggregate on heating start in the first 5 min. The fibrillation through aggregation process continues until 30 min on heating. The similar phenomenon occurs in the presence of zinc ions. The SAXS data suggest that the presence of zinc ions prevent the long cylindrical fibril at the beginning of heating. However, after 20 min heating, the large cylindrical fibril of insulin formed in both conditions.

Abstract: Gypseous soil disturbed in many regions in the world. Existence of this soil with high gypsum content caused many damages to the buildings and structures that built on it due to dissolve and leaching of the gypsum slates by the flow of water through the soil mass. Therefore, it is necessary to study the properties of such soil. The dissolve of gypsum depends on many factors such as (gypsum content, temperature and other factors). Another important factor which is the acidity of the dissolution liquid must be considered. This study observes the influence of Acetic acid (CH3COOH) on the gypseous soil. Laboratory models includes (270 mm diameter) and (500 mm height) thick steel cylinder container and 17.1 kN/m3 density gypseous soil compacted in three layers, with gypsum content about 58% . The relation between the soaking time and the shear strength parameters was investigated. Also, plastic square container dimensions (250 mm x 250 mm x 300mm) used with same conditions to observed the deformation of the soil. The aim of this study is to simulate the infiltration of Acid in Gypseous soil. Test results show that increase cohesion of soil for diluted acid while decrease cohesion values for concentrated acid. Angle of friction for soil was increase for diluted and concentrated acid.

Abstract: The article describes the influence of the acidity degree of oxide compounds formed on contact surfaces of carbide cutting tools type P on their wear resistance when cutting materials causing intensive diffusion wear. It was found out that when the acidity degree of surface film oxides formed on the cutting wedge contact surfaces decreases, wear resistance of cutting tools tends to grow.

Abstract: The mordenite zeolite is one of the most important industrially zeolites, used as a solid catalyst for various reactions hydrocracking, hydroisomerization, alkylation, reforming, alkane oxidation, Fischer-Tropsch reaction. The aim of this study was to hydrothermal synthesis mordenite zeolite in its sodium form under hydrothermal conditions, in organic-free synthesis. The form HMOR of the zeolite mordenite was obtained by an ion exchange. For the preparation of the catalysts precursor salts were used: ammonium heptamolybdate, nickel nitrate, cobalt nitrate dispersed from the impregnation by incipient wetness impregnation, such impregnated supports were calcined at 550 °C/4h to obtain the catalyst. The zeolite synthesized in the sodium form NaMOR in its ammonium form NH₄MOR in form acid HMOR and their catalysts MoO₃/HMOR, NiO/HMOR and Co₂O₃/HMOR were characterized by X-ray diffraction (XRD) and Fluorescence Spectroscopy of by Energy X-ray dispersive (FRX-ED). From the results it was possible to observe the formation of zeolite phase mordenite in its sodium and acid form and the effective impregnation and formation of the proposed catalysts.