ORIGINAL RESEARCH ARTICLE | Aug. 8, 2021
A Kinetic Study Based on Spectrophotometric and Titrimetric Evaluation for the Formation of Rubazoic Acid Type Derivative from 4-Amino-1(4-Sulphophenyl) 3-Methyl-2-Pyrazolin-5-One during Its Diazotization
Hafiz Tassawar Hussain, Ghulam Shabir, Aamer Saeed, Noor Hassan, Tayyaba Shabir, Zobia Yaseen, Saira Irshad, Muhammad Nadeem Akhtar, Nasir Abbas, Shakeel Ahmad
Page no 174-179
A kinetic study based on spectrophotometric and titrimetric techniques has been carried out for the formation of Rubazoic acid type derivative from 4-amino-1(4-sulphophenyl) 3-methyl-2-pyrazolin-5-one (4-amino SPMP). Physico-chemical factors like effect of Time, pH, aeration and temperature on the formation of Rubazoic acid derivative have been studied in detail. The oxidizing and diazotizing property of nitrous acid has been evaluated for 4-amino-SPMP. Moreover the diazonium compound of SPMP was isolated and its stability in solid form has also been investigated.
ORIGINAL RESEARCH ARTICLE | Aug. 8, 2021
Chemical Desulphurization of Coal using KOH as Oxidizing Agent in the Presence of Deep Eutectic Solvent
Akasha Saleem, Nasir Abbas, Dur-e-Shehwaar, Tayyaba Shabir, Noor Hassan, Muhammad Munawwar
Page no 180-195
Coal is a great source of energy gifted by the nature. Main hazard in the use of coal is the production of sulphur oxides, sulphur dioxides, and nitrogen oxides which affect the climate severely. To protect environment from these hazardous oxides of sulphur, clean coal technology is being introduced and applied all over the world. Various desulphurization methods such as chemical, physical or biological have been used. In this study oxidative desulfurization using highly efficient deep eutectic solvent (DES) was carried out by ultra-sonication method. Choline chloride and ethylene glycol in 1: 2 ratios were used to prepare DES. Oxidative desulfurization process was utilized to treat coal samples using KOH as an oxidant. Oxidative desulphurization (of organic/inorganic sulphur forms) of coal was achieved by using deep eutectic solvent. ASTM methods were used to estimate different forms of sulphur in coal. The Fourier Transform Infrared spectroscopy (FTIR) was used to estimate the amount of sulphur removed from three different coal samples.
ORIGINAL RESEARCH ARTICLE | Aug. 16, 2021
Equilibrium Modelling, Thermodynamic and Kinetic Studies on the Bio Sorption of Malachite Green Dye by a Low Cost Effective Adenanthera Pavonina Leaves Activated Carbon
V. Anbarasan, Sujatha Dhadhala, A. Alvin Kalicharan, K.Arivalagan
Page no 196-203
The aim of the current work is to investigate the applicability of raw Adenanthera Pavonina Leaves Activated Carbon (APLAC) for the removal of Malachite Green (MG) in aqueous solution. The adsorption of Malachite Green (MG) on APLAC adsorbent was studied as a function of APLAC dose (0.2–1g), initial concentration (10–70mg/L), pH 4–9 solutions, and a varying contact time(30-150)minutes and temperature(298-328)K. The effect of these parameters on the adsorption capacity was investigated using a batch process. The experimental data were fitted to Langmuir, Temkin and Freundlich adsorption models and were found to coincide Freundlich adsorption isotherm. Kinetic data were fitted to the pseudo-first-order and pseudo second-order models, and were found to follow pseudo- second-order kinetic model. The Characterization of the APLAC adsorbent was achieved by FT-IR, UV and SEM techniques. This study reveals that APLAC is eco benign and has a very good dye uptake property and can be best used as low cost and effective adsorbent in removing the environmentally polluting dyes.
ORIGINAL RESEARCH ARTICLE | Aug. 21, 2021
Chloride Threshold Ingress Evaluation of Corrosion Probability Using Concrete Electrical Resistivity and Half-Cell Potential Measurements
Macmammah Michael, Gbinu Samuel Kabari, Charles Kennedy
Page no 204-220
The application of Sticky gummy paste of anogeissus combretaceae exudates/resin extracted from tree extrudes was studied. It was used as an inhibitive material to control the manifestation corrosion effect on steel bars in built-in high salinity coastal areas. The extracted exudates/resin was coated to reinforcing steel and embedded in the concrete slab, exposed to corrosive media with high salt concentration. The results of maximum calculated percentile of the controlled sample value is -64.36% compared to the corroded and coated value of 154.98% and -60.05% and the controlled corrosion potential differential value is 1.19%, corroded 4.66% and coated 0.73% . The maximum yield of controlled and coated samples was -108.04mV and -122.85mV, which showed the relationship between corrosion potential and probability reference of 𝐸corr > −200mV as a reference range. For non-coated (corroded) samples, the maximum calculated value is -310.58mV; the result is within the reference value of the relationship between corrosion potential and probability of −350mV ≤ 𝐸corr ≤ −200mV value indicating a high value range close to 10% or an uncertain corrosion probability in comparison to the reference range. The maximum calculated percentile of the controlled sample concrete resistance is 141.67% compared to the corroded and coated value of -52.84% and 131.05% and the maximum percentile differential of control are 23.15% compared to the corroded and coated value of 3.87 % and 18.94%. The results of the controlled and layered concrete resistance samples obtained a maximum average value of 15.96kΩcm and 15.47kΩcm with a data value of 10 < 𝜌 < 20 (low) compared to a corrosion value of 7.28kΩcm with a specification of (5 <𝜌 < 10) and with the reference range of the relationship between concrete resistance and corrosion probability. The maximum percentile value calculated from the controlled yield strength is 9.96% against corroded sample and the coated value is -9.21% and 10.67% and the possible differentials value is 0.43% controlled 0.43% corroded and 0.52% coated. The calculated maximum values of the controlled tensile strength percentiles were 2.348% against corrosion and the coated values were -4.08% and 4. 27% and the potential differential values were 0.01% checked, 0.01%% corroded and 0 0.01% coated. The coated samples for yield strength, tensile strength and deformation ratio of the average, percentile and differential potential values of the control, plate samples. uncoated (corroded) and coated concrete had higher breaking loads compared to corroded specimens with reduced failure loads and low load bearing capacity and with average and percentile values compared to the reference range, whereas uncoated samples (corroded) indicated a low load-bearing capacity and reduced value compared to the reference range. The diameter of reinforcement after corrosion maximum calculated percentile value controlled 0.043% versus -1.11% corroded and 1.114% coated, the difference in percentage between corroded 0.121% versus 0.008% coated. The effect of corrosion attack on reinforcing steel embedded in the concrete slab and exposed to corrosion induced acceleration effect. The aggregate results show that the corrosion effect causes a weight reduction/weight reduction in the corroded samples compared to coatings with a percentage exposure and an average increase, resulting in a small increase in the volume of the coating thickness. This study shows the effectiveness and efficiency of exudates/resin as an inhibitor against the effects of corrosion on reinforcement embedded in samples of concrete slabs exposed to induced corrosion.
ORIGINAL RESEARCH ARTICLE | Aug. 21, 2021
Rib Geometry as Functional Parameter on Bond Strength of Exudate-Coated and Non-Coated Reinforcing Steel Exposed to Corrosive Media
Gabriel Okonkwo Nnaji, Charles Kennedy, Eze Chinonso Emmanuel
Page no 221-234
surrounding concrete structure. The research work investigated the application of exudates/resin as an inhibitory substance in averting the effect of corrosion on reinforced concrete structures in the built environment of high salinity. The experimental data tests were carried out on 36 concrete cubes with the first set of 12 controlled concrete samples placed in freshwater for 360 days and the second set of 24 cubes divided into 2 with 12 uncoated samples and 12 coated samples with exudate/resin as described in the test procedure and immersed in 5% aqueous sodium chloride (NaCl) solution for 360 days, routine three months with 90-day intervals, 180 days, 270 days, and 360 days. Comparatively, the minimum and maximum values for average and percentile for failure bond loads, bond strength and maximum slip, cross-sectional reduction/increase, the diameter of rebar before /after corrosion, weight loss/gain. The listed results show reduced values with the application of lower failure loads of corroded samples compared to controlled and coated samples with closer values and higher failure loads. The calculated and comparable value for the bond strength of the controlled samples was 69.572% compared to the corroded and coated samples with -42.481% and 98.031%. The indicative count results showed a reduced value and lower failure load of corrosive samples and for samples coated with a value that increases with the reference value in the controlled sample range. In comparison, the corroded samples showed a lower slip value compared to the controlled and coated samples with a higher slip value compared to the failure status, indicating a contribution to the exudate/resin effect in the slip test. The calculation results show an indication of the effect of corrosion on failure bond load, bond strength, and maximum slip. The presence of corrosion reduces the efficiency of the material used, reduces mechanical properties, and affects the bonding and interactions between the concrete and the steel reinforcement and the surrounding concrete. The results obtained indicate that the effect of corrosion on reinforcing steel hurts the mechanical properties of the cross-sectional area, a decrease in diameter and weight loss and surface modification, thereby reducing the value of control slip and coated samples and reducing the interaction between concrete and reinforcing steel.
ORIGINAL RESEARCH ARTICLE | Aug. 30, 2021
Induced – Corrosion Mechanism on Splitting and Pullout Failures of Corroded and Coated Reinforced Concrete Members
Arube Goodnews Emuakpo, Overo Kenneth Ejukonemu, Charles Kennedy
Page no 235-246
Corrosion of reinforcement embedded in concrete is considered as one of the main reasons for the degradation and deterioration of many existing reinforced concrete structures and this degradation effects has been seen as major challenges in structures founded in region with high concentration of salt as in the case of the Niger Delta region of Nigeria. This study involves the coating of ficus sycomorus exudates/resin paste of plant trunks extract known as inhibitors directly on the reinforcing steel. The experiment aimed at determining the effectiveness in the use of eco-friendly and abundantly available materials in curbing the negative effect of corrosion attacks on reinforcing steel embedded in concrete structures and immersed in Sodium Chloride (NaCl) solutions by coating steel reinforcement with different thicknesses and experimentally tested to prevent corrosion attacks in the laboratory. The test specimens reflect the acute acidic level indicating the sea salt concentration level of the marine environment on reinforced concrete structures. The result showed that the decreased value in uncoated (corroded) represent the degree of corrosion that has to affect the bonding interaction between concrete and reinforcing steel, also, the negative values obtained in bond strength versus maximum slip showed that the reduction in slip was due to the effect of corrosion. The higher values obtained from coated members showed the potential and the effective interaction process in steel and concrete, results showed that the values of coated members are similar to that of controlled indicating the virtuous bonding characteristics. The result of weight loss for controlled samples are 100% indicating no weight loss, uncoated (corroded) samples negative values showed tremendous weight loss resulting from corrosion presence, and for coated samples, there are weight gain resulting from coating materials. Also, the effect of corrosive medial reduces the diameter of reinforcing steel after corrosion, the effect of corrosion formed pits which resulted to swollen rebar surface whereas coated and controlled maintained perfect diameter with an increasing diameter from coating thicknesses. Reduction in cross–sectional properties, weight loss was all seen in corroded samples resulting from damaging and destructive effect from corrosion manifestation while coated gained weight and as well as increased in cross-sectional properties. Clear examinations on the study and investigations, coated exudate/resin has demonstrated and shown to be good inhibitive material against corrosion.
ORIGINAL RESEARCH ARTICLE | Aug. 30, 2021
Electrochemical Mechanism of Reinforcing Steel Corrosion Current Measurement using Wenner Techniques
Charles Kennedy, Amadise S. Ogboin, Philip Kpae. F. O
Page no 247-264
Environmental conditions include chloride penetration (eg de-icing salt or seawater) and carbonization of concrete. This protective effect may fail, but the provisional quantification of this process to assess the service life of reinforced concrete structures is an important task both in the planning stages of new buildings and in the context of renovation of existing buildings. The application of Boswellia dalzielii Hutch extruded viscous gummy paste (exudate/resin) obtained from the tree was studied in the research exudate/resin. Its utility as an inhibitive material in the curbing of corrosion effect on reinforcing steel built within the coastal region of high salinity. Extracted exudate/rein was coated to reinforcing steel and embedded into the concrete slab, exposed to corrosive media with a high concentration of salt. The experimental data of corrosion potential Ecorr, mV and concrete resistivity, kΩcm of maximum percentile value calculated from the concrete resistivity of the controlled sample concrete is 134.14% compared to the corroded and coated value of -31.11% and 88.07% and the maximum value of the percentile differential from the control is 49.97% compared to the corroded and coated value of 15.72% and 42.9%. The results of the controlled and coated concrete resistivity samples obtained of the maximum average values are 15.05kΩcm and 12.09kΩcm with a description of the value 10 <𝜌 <20 (low) compared to the corrosion value of 8.15kΩcm with Specifications 5 <𝜌 <10 ( high) and with a reference range of dependence between concrete resistivity and corrosion probability significant corrosion probability (𝜌 < 5, 5 < 𝜌 < 10, 10 < 𝜌 < 20, 𝜌 > 20) for very high, high, low to medium and low, for possible corrosion. The maximum calculated controlled percentile value was -66.02% compared to the corroded and coated values 171.66% and -62.28% and the controlled potential differential value was 1.7%, corroded 6.56% and coateded 0.91%. The maximum half-cell potential yields of controlled and coated samples were -107.1mV and -121.98 mV, which showed the relationship between corrosion potential and probability as a 𝐸corr > −200mV as a reference range. The results of this corrosion potential Ecorr, mV result show that the controlled sample values and exudates/resin coated are low with a 90% probability that no corrosion of the reinforcement is observed at the time of measurement (10% corrosion risk, 10% or shows an uncertain corrosion probability for samples that uncoated, the maximum calculated value is -328.22mV, the result is within the reference value of the dependence between the corrosion potential and probability of the value −350mV ≤ 𝐸corr ≤ −200mV indicates a high range of values, which is a corrosion probability of 10% or uncertain of the reference range (controlled) shows that the corrosion samples show corrosion as a result of accelerated corrosion induced as compared to the coated samples which show no corrosion. The maximum percentile calculated from the ultimate tensile strength is controlled by 2.99% in terms of corrosion and coating values are - 2.97% and 3 0.01% respectively and the potential differential value of 0.14% is controlled, 0.12% is corroded and 0.09% is coated. The calculated maximum percentile of the controlled yield strength is 9.08% relative to corrosion and coated values are -7.83% and 8.61% and the possible differential values are 1.42% controlled, 0.09% corroded and 4.29% coated. The maximum percentile value calculated to compare the strain ratio was checked at -7.21% against corroded 5.36% and coated -7.23%, and the maximum differential was checked for 0.08%, corroded 0.2% and coated 0.1%. The comparative results show that the low load carrying capacity is caused by the effect of corrosion attack on the uncoated (corroded) elements, which damage the reinforcing steel fibers, ribs and passive formation and surface modification. The observed mean values for the coated samples were associated with the corrosion resistivity potential to penetrate the reinforcing steel with the formation of a protective membrane; This attribute indicates the effectiveness of the exudate / resin as an inhibitor against corrosive effects of reinforced concrete structures exposed to heavy marine areas with high salt content. The maximum calculated percentile diameter of the reinforcement after corrosion was controlled 0.368% versus corroded - 0.903% and coated 0.796%, with a different percentile of corroded 0.011% versus 0.007% coated. For comparative, the results of the corroded samples showed a reduction and reduction value compared to the diameter of the reinforcement before and after the induction accelerated corrosion test with a percentile decrease in value from 0.368% to -0.903% and an average value in the range from 11.98mm to 11.94mm. The cross-sectional area differential in mean values and relative percentiles between coated and corroded samples ranged from 39.02% to -28.07%. ......