Mechanical Properties of Hot Rolled Ribbed and Plain Steel Rods

This study focuses on microstructure and mechanical behaviour of 3PS (Semi-killed mild steel) hot rolled ribbed and plain carbon steel. 3PS billet steel samples and hot rolled ribbed and plain steel rods of different heat numbers and profiles were characterized for its chemical composition, microstructure, and tensile behaviour. The composition analysis of 5 (five) 3PS billet samples shows that there was no appreciable variation in chemical composition of the hot-rolled plain and ribbed steel rods. The microstructures of as-received steel billet (3PS) examination revealed large grains of ferrite and pearlite while those of hot-rolled 3 PS mild steel samples of different heat numbers contain smaller grains of ferrite and some amount of pearlite. The results also indicated that yield and ultimate tensile strength reach maximum values (492 and 361 N/mm2) at 0.31% elongation for heat number 43 while maximum values for heat number 56 (478 and 362 N/mm2) at 0.33 % respectively. The ribbed steel rod of the same diameter as plain steel exhibit slightly better mechanical properties with higher values of yield and ultimate tensile strength. There is consistency in the chemical composition of the as-received billet and the hot rolled products

Performance Evaluation of a Single Cylinder Spark Ignition Engine Fuelled by Mixing Ethanol and Gasoline

The use of ethanol blend as an alternative source of fuel for developing clean and sustainable energy sources has grown considerably. In this study, the performance characteristics of an air-cooled, single-cylinder 4-stroke Spark Ignition (SI) engine (TD201) with a compression ratio of 8.5:1 was determined using gasoline and different blend ratios of ethanol and gasoline (E0, E2, E4, E6, E8, E10, and E12) at a varied engine speed of 2000rpm, 2200rpm, 2400rpm, 2600rpm and 2800rpm. The results revealed that as the ethanol content of the blend increases, the heating value decreases while octane value increases. The experimental results indicated that the brake torque, and power increase as the ethanol content in the blends increases. However, BSFC and exhaust temperature decreases as the ethanol content in the blends increases because of the oxygen enrichment. The emissions of unburned hydrocarbon and carbon monoxide reduce while carbon dioxide and ethanol content increases when compared with the reference fuel (E0)

Simulation and experimental study of the sensor emitting frequency for ultrasonic tomography system in conducting pipe

Ultrasonic tomography techniques provide flow visualization capability, non-invasively and non-intrusively, to enhance the understanding of complex flow processes. There is limited ultrasonic research in tomography imaging systems in the tomogram analysis of fluid flow in a conducting pipe because of a high acoustic impedance mismatch, which means that very little ultrasonic energy can be transmitted through the interface. The majority of industrial pipelines are constructed from metallic composites. Therefore, the development and improvement of ultrasonic measurement methods to accommodate a stainless steel pipe are proposed in this paper. Experimental and simulation distribution studies of the ultrasonic emitting frequency in acrylic versus stainless steel pipes were studied, measured and analyzed. During the simulation, ultrasonic transducers were placed on the surface of the investigated pipe to inspect the ultrasonic sensing field. The distribution of the sound wave acoustic pressure was simulated based on the physical dimensions and parameters of the actual experimental hardware set-up. We developed ultrasonic acoustic models using the finite element method with COMSOL software, and experiments were carried out to validate the simulation results. Finally, by performing the static phantoms tests, a feasibility study of ultrasonic tomography system was presented to investigate the void fraction of liquid column inside a stainless steel pipe

Effects of cold extrusion on the mechanical properties of scrapped copper coil

The recycling of copper coil into finished products via sand casting with subsequent cold extrusion was investigated. This paper examined the effects of cold extrusion on the mechanical properties of the scrapped copper coil using a locally manufactured extruder with a conventional face die. The mechanical properties tested on the extrudates are limited to hardness, tensile, and compressive strength. The results reveal that the hardness of extruded copper of 11.10 mm and 11.45 mm improved significantly by 39 % and 41 %, respectively, compared with respective non-extruded copper. The compressive and tensile strength increases by 42 % and 22 %, respectively, for 11.10 mm extruded copper compared with the corresponding non-extruded copper. Also, the elongation of the extruded copper of 11.10 mm and 11.45 mm increases by 33 % and 34 %, respectively. It was deduced that the extruded copper is more ductile than the non-extruded copper. The micrograph reveals that grains in non-extruded copper are relatively coarse and nonuniform with voids, but fine and relatively uniform grains are obtained in extruded copper. The grains are refined during cold extrusion, and voids and dislocations are reduced significantly

Optimization of fuel briquette made from bi-composite biomass for domestic heating applications

This study aimed at optimizing the fuel briquettes produced from flamboyant pod (FBP), and corn cob (CC) mixed with cassava starch (SB) as a binder using custom design methodology (CDM). The compressive strength, ash yield, and emission analysis of the briquettes produced were determined. The combustion efficiency parameters as well as CO, NO2, PM2.5, and PM10 of the emissions were compared to optimal fuel briquettes and charcoal fuel. The optimal combination of compressive strength and ash yield was obtained for the briquette fuel blend formulated from 30 wt.% flamboyant pod, 51 wt.% corn cob and 17 wt.% starch. While the water boiling time of the fuel increased by about 35–48% compared to charcoal fuel, the ignition time and the specific fuel consumption rate decreased by ∼34% and 16%, respectively. Furthermore, the major air pollutants were reduced from 222 to 196 ppm for CO, 3.63–2.34 ppm for NO2, and 0.21–0.09 ppm for PM 2.5. These properties of the briquette align with charcoal, thus supporting the use of flamboyant-corcob-starch (FBCS) briquettes as a supplementary source of energy to charcoal

Experimental investigation of double slope solar still integrated with PCM nanoadditives microencapsulated thermal energy storage

Transparent covered slope solar stills are trending but characterised with low productivity, heat losses and high energy consumption, which are setbacks in practice. In this study, double slope solar still (DSSS) integrated with PCM-TES is presented. PCM was microencapsulated with epoxy resin composite using vacuum mould-filled techniques. Conventional DSSS and DSSS-TES data collected have been compared to establish the influence of TES on productivity. Daily average temperature of the glass cover, humid air, saline water, still basin absorbern and TES cavity for the DSSS-TES attained are 65.2 ◦C, 77.5 ◦C, 82.4 ◦C, 79.5 ◦C and 68.4 ◦C, respectively. DSSSTES has yielded higher production, with 7.5 Litres of potable water daily and extension in operation period by 3 h has been achieved. In addition, condensation and evaporation rates increased with increase in production by 105%. Integration of TES with the system has reduced the heat losses while leakages from PCM nanocomposite have been prevented by microencapsulated insulator. No trace of metals, bacteria and organic contaminants has been found in desalinated water. A payback period of 0.8 year has been recorded based on all-year-round operations. Findings are in good agreement with existing models. Moreover, sensorial characteristics obtained conform to WHO standards

Experimental investigation of double slope solar still integrated with PCM nanoadditives microencapsulated thermal energy storage

Transparent covered slope solar stills are trending but characterised with low productivity, heat losses and high energy consumption, which are setbacks in practice. In this study, double slope solar still (DSSS) integrated with PCM-TES is presented. PCM was microencapsulated with epoxy resin composite using vacuum mould-filled techniques. Conventional DSSS and DSSS-TES data collected have been compared to establish the influence of TES on productivity. Daily average temperature of the glass cover, humid air, saline water, still basin absorber and TES cavity for the DSSS-TES attained are 65.2 ◦C, 77.5 ◦C, 82.4 ◦C, 79.5 ◦C and 68.4 ◦C, respectively. DSSSTES has yielded higher production, with 7.5 Litres of potable water daily and extension in operation period by 3 h has been achieved. In addition, condensation and evaporation rates increased with increase in production by 105%. Integration of TES with the system has reduced the heat losses while leakages from PCM nanocomposite have been prevented by microencapsulated insulator. No trace of metals, bacteria and organic contaminants has been found in desalinated water. A payback period of 0.8 year has been recorded based on all-year-round operations. Findings are in good agreement with existing models. Moreover, sensorial characteristics obtained conform to WHO standards