51 research outputs found
Effects of Cassava Starch and Natural Rubber as Binders on the Flexural and Water Absorption Properties of Recycled Paper Pulp Based Composites
No full textResponsiveness was given to the effects of cassava starch and natural rubber as binders on the flexural strength and the water absorptivity properties of the developed rattan particulate reinforced paper pulp based composites. Paper pulp was produced by chopping waste papers into smaller pieces and soaked in boiled water after which it was stirred thoroughly to form paper pulp. Rattan particulate was produced by hammering, chopping, pounding and milling of rattan canes followed by sieving into a particle size of 437 µ. Varying mass of paper from 300-400 g and particulate rattan in treated and untreated form of 2-8 g were mixed and bonded with natural rubber and cassava starch, respectively for the various samples developed. The mixtures were thoroughly mixed to produce homogenous pastes and poured into 150 x 50 x 30 mm detachable mould and compacted for 5 minutes using a laboratory compaction machine maintained at 20 KN. The developed composites were allowed to cure at room temperature for 27 days after which flexural and water absorptivity tests were carried out on the samples. It was noticed that the composite samples ST4 and S5 containing cassava starch happen to be the best in terms of flexural strength while NR2 gave the best water- repellent outcome
Effect of welding current and voltage on the mechanical properties of wrought (6063) aluminium alloy
No full textEffect of welding current and voltage on the mechanical properties of wrought (6063) aluminium alloy
No full textThis work was carried out to investigate the effect of welded joints on the mechanical properties of wrought (6063) aluminium alloy. The study revealed the influence of current and voltage on the welded joint as well as the mechanical properties of the alloy. The alloy samples were welded together by metal inert gas welding process at varying values of current and voltage after which mechanical tests were performed on the welded samples. The microstructural examination of the various fusion zones obtained was carried out. Appreciable variations in the properties of the welded samples were observed due to changes in the microstructural features of the alloys. It was concluded that variation of current and voltage remarkably affect the mechanical properties of the wrought 6063 Aluminium alloy. As the voltage increases from 25 to 30 V, the ultimate tensile strengths and hardness values increases while the impact strengths decreases but the current did not show such trend
Chief Isaac Oluwole Delano: The Man, His Time, and His Significance
No full textChief Isaac Oluwole Delano was a Nigerian expert in the Yoruba language and culture who was born in the Ifo District of the Abeokuta Province on the 4th of November, 1904.2 He was born to the family of Chief Edmund Delano and Rebecca Delano (both Egba indigenes). His educational exploits started from Holy Trinity Primary School situated at Okenla Christian Village in Ifo. From there, he was moved to Lagos Grammar School under the tutelage of an Anglican Bishop, Solomon Odutola, and his principal, Reverend E. J. Evans. However, situations necessitated his transfer to Kings College in 1921 where he met with his lifetime friends and college mates; Sir Adetokunbo Ademola, Justice N.O.A. Morgan as well as Dr. Oladele Ajose, to mention a few. Having passed his Senior Cambridge Examinations in 1923, Chief Delano proceeded to successfully write his Senior Clerical Examination in 1924, which propelled him to join the civil service in the same year. However, a severe injury sustained from an accident in 1947 led to his invalidation from the civil service. Worthy of note is the fact that he never blended into the civil service bureaucracy, as his principles and religious faith were constantly tested by various practices within the service. His dream to become more lettered was not going to succeed by his involvement with the civil service alone, and he was not positioned in those days to enjoy the privilege of travelling overseas to further his education. He had studied shorthand, and his love for writing by default made him aspire to a lifetime of authoring. While belonging to a number of literary societies, he tried his hand at writing newspaper articles which were generally well-received by the public. He was able to maintain a following from there, and this fueled his desire to write more works for public consumption; he was determined to make his mark in the field of writing. His first work as an author was published in 1937 under the title The Soul of Nigeria. Tis feat gave him his first taste at writing as an occupation, and the happiness that followed suit spurred him to achieve more. Isaac Delano believed that the first one was always going to be the hardest. His first published work had landed him on top of the world, and he was determined not to rest on his oars
Mechanical and Water Absorption Properties of Alkaline Treated Coconut (cocosnucifera) and Sponge (acanthus montanus) Fibers Reinforced Polypropylene Composites
No full textAbstract Natural fiber reinforced polymer composites have raised great attention and interest among researchers in recent years due to the consideration of developing an environmentally friendly and recyclable materials. In this research, the effect of alkaline treatment on the mechanical and water absorption properties of polymer composites developed from coconut and sponge fibers was investigated. The selected fibers were extracted by mechanical decortications and then cut into 10 mm length using scissors. The fibers were chemically treated with KOH in a shaker water bath before dispersing them randomly in polypropylene (PP) matrix. Composites with 2, 4, 6, 8, 10 wt% fibers were developed by compression molding. Tensile and flexural properties were evaluated using universal testing machine while water absorption test was carried out on the samples for 7 days. The research outcomes show that alkaline treatment of the fibers improved the flexural, tensile and water repellant properties of the developed composites
Studies of the properties of heat treated rolled medium carbon steel
No full textInvestigations were carried out to study critically the effects of heat treatment on the properties of rolled medium carbon steel. Representative samples of as-rolled medium carbon steel were subjected to heat treatment processes which are; Quenching, Lamellae Formation and Tempering in the following order (Q + Q + L + T), (Q + L + T) and (L + T). The steel was heated to the austenizing temperature of 830 ºC and water quenched. The quenched steel was subjected to lamellae formation by reheating it to the ferrite-austenite dual-phase region at a temperature of 745 ºC below the effective A C3 point and then rapidly quenched in water. The lamellae formed was tempered at 480 ºC to provide an alloy containing strong, tough and lath martensite in a soft and ductile ferrite matrix. Mechanical tests were carried out on the samples and the results shows that the steel developed has excellent combination of tensile strength, hardness and impact strength which is very good for structural applications. The corrosion behaviour of the samples; heat treated rolled medium carbon steel and as-rolled medium carbon steel in sodium chloride medium were also investigated from where it was also confirmed that improved corrosion resistance is achievable by the treatment
The effect of weld geometry and post-weld heat treatment on the corrosion behaviour of austenitic stainless steel immersed in 1.0 M NaCl solution
No full textThe variation of welding parameters such as weld geometry and post-weld heat treatment on the corrosion behaviour of austenitic stainless steel in a saline environment of 1.0 M NaCl was investigated in this work. Rods of austenitic stainless steel of known chemical composition were prepared and welded using electric arc welding technique varying the aforementioned parameters. Thereafter, samples for the corrosion behaviour investigation were then cut out of the welded rods. The analysis of the experimental data revealed that the best weld geometry was chamfered and a post-weld heat treatment carried out at temperatures in excess of 700 °C followed by air cooling improves the quality of a weld
Polymer-Based Composites: An Indispensable Material for Present and Future Applications
No full textRight from the early days, polymer materials have been discovered as being beneficial for various applications but a poor understanding of these materials greatly handicapped their usage. However, with a change in this trend, polymer materials have gradually displaced other materials in most applications. In recent times, due to improved research and knowledge, polymer-based materials are the first choice materials for several applications and are now replacing other materials rapidly. More advanced materials from polymers are being developed daily as a substitute for other materials even in areas where polymers are considered not to be suitable in the time past. More recently, polymers have replaced metals and ceramics in applications like constructions, aerospace, automobiles, and medical. It is no doubt that this trend will continue due to the inherent properties of polymers and sustainability potential. Today, most of the limitations of polymers are being taken care of in the formulation of composite materials. Besides, the adaptation to positive environmental influence is being handled by scientists and researchers. Hence, this review reveals core areas of application of polymer-based composites and the significance of these materials to the advancement of humanity
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