Corrosion is one of the major problems of mild steels in acidic medium. This can be minimized by ... more Corrosion is one of the major problems of mild steels in acidic medium. This can be minimized by the application of corrosion inhibitors, however; the most of inhibitors are toxic in nature. Therefore inhibitors from green sources are highly desirable to maintain the sustainability of the environmental system. Consequently, in this study ginger was selected; its juice extracted mechanically and used as an inhibitor. The different concentrations of ginger extract such as 0.25ml, 0.5ml, 0.75ml and 1ml were mixed in 0.1 M HCl solution to record the effect of inhibitor on corrosion rate at room temperature and at an elevated temperature of 50ᵒC. Electrochemical linear polarization resistance (LPR) tests were carried out to determine the corrosion rates at both temperatures with different additions of the inhibitor respectively. The LPR test uses three electrodes, first electrode of AISI 1019 (mild steel), second electrode is standard electrode of saturated calomel while the third electr...
Cold heading quality CHQ steel is a versatile form over other steels as they are used non-heat tr... more Cold heading quality CHQ steel is a versatile form over other steels as they are used non-heat treated; their strengthening mechanism is achieved through cold heading operations. Metal is therefore stretched without applying any source of heat, metal flow during the cold heading operation must depend on grains flow which increases the mechanical properties such as strength, resistance to indentation and toughness. It is therefore necessary to form the isotropic grains before applying cold heading operation may increase the properties. Gamma phase formation during the heat treatment is crucial factor for cold operation. An effort is made in this research work to study and find out the Austenite nucleation and growth morphology of commercial CHQ steel through continuous heating experiments by utilizing lead-bath up-quenching technique at differentaustenizing temperature ranges. High class Optical Microscope Olympus GX51, scanning electron microscopy techniques have been utilized to re...
The replacement of lead zirconate titanate ceramics (PZTs), with a lead-oxide (PbO)free alternati... more The replacement of lead zirconate titanate ceramics (PZTs), with a lead-oxide (PbO)free alternative is the subject of intense investigation worldwide. In this research, a cheap reliable methodology for the fabrication of multilayers (MLs) of lead-free potassium sodium niobate (KNN)-based ceramics is presented without the need for vacuuming and/or hot isostatic pressing of the tape. The thickness per active layer was 193 µm and 102 µm for the 10 and 16 layer MLs actuators, respectively. Effective d 33 (piezoelectric coefficient), effective d 33 * (electrostrain coefficient), bi-polar strain (S max), max displacement, dielectric constant (r) and loss (tanδ) are 2500 pC/N, 4604 pm/V, 0.17%, 2.2 µm, 1812 and 2% at 1 kHz, respectively, where the effective d 33 or d 33 * is the total output of all layers together. The ultimate target materials for potential substitution with KNN-based ceramics and MLs are commercial PZT-4 and PZT-8.
Mehran University Research Journal of Engineering and Technology
Cu2O (Cuprous Oxide) is usually produced using expensive electrodes such as platinum, graphite, e... more Cu2O (Cuprous Oxide) is usually produced using expensive electrodes such as platinum, graphite, etc. In the present study, it is shown that Cu2O nanostructures can be synthesized by electrolysis using copper as both anode and cathode. In the present study, the effect of electrolyte pH on the morphology of the Cu2O nanostructures was studied. For this, the copper electrodes of 99.99% purity with 3x3x0.3 mm dimensions were dipped in the electrolytes of simple distilled and double distilled water and connected with the external power source. The synthesized products were analyzed using SEM (Scanning Electron Microscope), EDS (Energy Dispersive Spectroscope) and UV spectroscope. Results showed that Cu2O nanostructures of 67 and 150 nm size were developed when the pH of electrolyte was 6.4 and 5.7 respectively, otherwise not. From the course of experiments conducted in this work it is noted that pH play vital role in the production of Cu2O nanoparticles using simple electrolysis technique.
Lead-free piezoceramics with the composition (1-x)(K 1-y Na y) NbO 3-x(Bi 1/2 Na 1/2)ZrO 3 (KNyN-... more Lead-free piezoceramics with the composition (1-x)(K 1-y Na y) NbO 3-x(Bi 1/2 Na 1/2)ZrO 3 (KNyN-xBNZ) were prepared using a conventional solid-state route. X-ray diffraction, Raman spectroscopy, and dielectric measurements as a function of temperature indicated the coexistence of rhombohedral (R) and tetragonal (T) phase, typical of a morphotropic phase boundary (MPB) as the BNZ concentration increased and by adjusting the K/Na ratio. High remnant polarization (P r = 24 lC/cm 2), piezoelectric coefficient (d 33 = 320 pC/N), effective piezocoefficient (d à 33 = 420 pm/V), coupling coefficient (k p = 48%), and high strain (S = 0.168%) were obtained at room temperature, but significant deterioration of P r , d à 33 , and k p were observed by increasing from room temperature to 160°C (17.5 lC/cm 2 , 338 pm/V, and 32%, respectively) associated with a transition to a purely T phase. Despite these compositions showing promise for room-temperature applications, the deterioration in properties as a function of increasing temperature poses challenges for device design and remains to be resolved.
Lead-free ceramics with the composition 0.91K 1/2 Bi 1/2 TiO 3-0.09(0.82BiFeO 3-0.15NdFeO 3-0.03N... more Lead-free ceramics with the composition 0.91K 1/2 Bi 1/2 TiO 3-0.09(0.82BiFeO 3-0.15NdFeO 3-0.03Nd 2/3 TiO 3) were prepared using a conventional solid state, mixed oxide route. The ceramics exhibited a high strain of 0.16% at 6 kV mm À1 , stable from room temperature to 175 C, with a variation of <10%. The materials were fabricated into multilayer structures by co-firing with Pt internal electrodes. The prototype multilayer actuator exhibited constant strains up to 300 C with a variation of $15%. The composition showed fatigue resistant behaviour in both monolithic and multilayer form after bipolar loading of 10 6 cycles. V
Corrosion is one of the major problems of mild steels in acidic medium. This can be minimized by ... more Corrosion is one of the major problems of mild steels in acidic medium. This can be minimized by the application of corrosion inhibitors, however; the most of inhibitors are toxic in nature. Therefore inhibitors from green sources are highly desirable to maintain the sustainability of the environmental system. Consequently, in this study ginger was selected; its juice extracted mechanically and used as an inhibitor. The different concentrations of ginger extract such as 0.25ml, 0.5ml, 0.75ml and 1ml were mixed in 0.1 M HCl solution to record the effect of inhibitor on corrosion rate at room temperature and at an elevated temperature of 50ᵒC. Electrochemical linear polarization resistance (LPR) tests were carried out to determine the corrosion rates at both temperatures with different additions of the inhibitor respectively. The LPR test uses three electrodes, first electrode of AISI 1019 (mild steel), second electrode is standard electrode of saturated calomel while the third electr...
Cold heading quality CHQ steel is a versatile form over other steels as they are used non-heat tr... more Cold heading quality CHQ steel is a versatile form over other steels as they are used non-heat treated; their strengthening mechanism is achieved through cold heading operations. Metal is therefore stretched without applying any source of heat, metal flow during the cold heading operation must depend on grains flow which increases the mechanical properties such as strength, resistance to indentation and toughness. It is therefore necessary to form the isotropic grains before applying cold heading operation may increase the properties. Gamma phase formation during the heat treatment is crucial factor for cold operation. An effort is made in this research work to study and find out the Austenite nucleation and growth morphology of commercial CHQ steel through continuous heating experiments by utilizing lead-bath up-quenching technique at differentaustenizing temperature ranges. High class Optical Microscope Olympus GX51, scanning electron microscopy techniques have been utilized to re...
The replacement of lead zirconate titanate ceramics (PZTs), with a lead-oxide (PbO)free alternati... more The replacement of lead zirconate titanate ceramics (PZTs), with a lead-oxide (PbO)free alternative is the subject of intense investigation worldwide. In this research, a cheap reliable methodology for the fabrication of multilayers (MLs) of lead-free potassium sodium niobate (KNN)-based ceramics is presented without the need for vacuuming and/or hot isostatic pressing of the tape. The thickness per active layer was 193 µm and 102 µm for the 10 and 16 layer MLs actuators, respectively. Effective d 33 (piezoelectric coefficient), effective d 33 * (electrostrain coefficient), bi-polar strain (S max), max displacement, dielectric constant (r) and loss (tanδ) are 2500 pC/N, 4604 pm/V, 0.17%, 2.2 µm, 1812 and 2% at 1 kHz, respectively, where the effective d 33 or d 33 * is the total output of all layers together. The ultimate target materials for potential substitution with KNN-based ceramics and MLs are commercial PZT-4 and PZT-8.
Mehran University Research Journal of Engineering and Technology
Cu2O (Cuprous Oxide) is usually produced using expensive electrodes such as platinum, graphite, e... more Cu2O (Cuprous Oxide) is usually produced using expensive electrodes such as platinum, graphite, etc. In the present study, it is shown that Cu2O nanostructures can be synthesized by electrolysis using copper as both anode and cathode. In the present study, the effect of electrolyte pH on the morphology of the Cu2O nanostructures was studied. For this, the copper electrodes of 99.99% purity with 3x3x0.3 mm dimensions were dipped in the electrolytes of simple distilled and double distilled water and connected with the external power source. The synthesized products were analyzed using SEM (Scanning Electron Microscope), EDS (Energy Dispersive Spectroscope) and UV spectroscope. Results showed that Cu2O nanostructures of 67 and 150 nm size were developed when the pH of electrolyte was 6.4 and 5.7 respectively, otherwise not. From the course of experiments conducted in this work it is noted that pH play vital role in the production of Cu2O nanoparticles using simple electrolysis technique.
Lead-free piezoceramics with the composition (1-x)(K 1-y Na y) NbO 3-x(Bi 1/2 Na 1/2)ZrO 3 (KNyN-... more Lead-free piezoceramics with the composition (1-x)(K 1-y Na y) NbO 3-x(Bi 1/2 Na 1/2)ZrO 3 (KNyN-xBNZ) were prepared using a conventional solid-state route. X-ray diffraction, Raman spectroscopy, and dielectric measurements as a function of temperature indicated the coexistence of rhombohedral (R) and tetragonal (T) phase, typical of a morphotropic phase boundary (MPB) as the BNZ concentration increased and by adjusting the K/Na ratio. High remnant polarization (P r = 24 lC/cm 2), piezoelectric coefficient (d 33 = 320 pC/N), effective piezocoefficient (d à 33 = 420 pm/V), coupling coefficient (k p = 48%), and high strain (S = 0.168%) were obtained at room temperature, but significant deterioration of P r , d à 33 , and k p were observed by increasing from room temperature to 160°C (17.5 lC/cm 2 , 338 pm/V, and 32%, respectively) associated with a transition to a purely T phase. Despite these compositions showing promise for room-temperature applications, the deterioration in properties as a function of increasing temperature poses challenges for device design and remains to be resolved.
Lead-free ceramics with the composition 0.91K 1/2 Bi 1/2 TiO 3-0.09(0.82BiFeO 3-0.15NdFeO 3-0.03N... more Lead-free ceramics with the composition 0.91K 1/2 Bi 1/2 TiO 3-0.09(0.82BiFeO 3-0.15NdFeO 3-0.03Nd 2/3 TiO 3) were prepared using a conventional solid state, mixed oxide route. The ceramics exhibited a high strain of 0.16% at 6 kV mm À1 , stable from room temperature to 175 C, with a variation of <10%. The materials were fabricated into multilayer structures by co-firing with Pt internal electrodes. The prototype multilayer actuator exhibited constant strains up to 300 C with a variation of $15%. The composition showed fatigue resistant behaviour in both monolithic and multilayer form after bipolar loading of 10 6 cycles. V
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