Anthropometric design of furniture for use in tertiary institutions in Abeokuta, South-western Nigeria

Students sit for most of the time on school furniturein the classroom. However, the design of schoolfurniture in Nigeria using the anthropometric dataof the users has yet to be given adequate attention.This study was carried out to obtainanthropometric data of students in higherinstitutions of learning in Nigeria for the design ofergonomics chairs and tables for use by students inthose institutions. Seven hundred and twenty (720)students in three selected institutions participatedin the study. Various body dimensions (sittingelbow height, shoulder height, knee height,popliteal height, buttock-popliteal length, statureand body weight) of the students were measuredusing standard anthropometer and 5 th, 50th, and95 th percentiles of the data obtained werecomputed using a SPSS 16.0 statistical package.The existing furniture dimensions in the selectedinstitutions were also measured. Based on theobtained anthropometric data, this paper proposesfurniture design dimensions for seat height, seatdepth, seat width, backrest height (upper), armrestand desk height for students in the selected tertiaryinstitutions. The present study may be a pointer tothe effect that in the design of tables and chairs foruse in higher institutions, the anthropometric dataof the Nigerian students were not considered. It ishereby recommended that similar study should becarried out in other sections of the country

Impacts of Carburizing Temperature and Holding Time on Wear of High Speed Steel Cutting Tools.

The paper presents a report on effects of variation in carburizing temperature and time on cutting tool to enhance its use in engineering applications. 30 pieces of HSS cutting tools (200 x 14 x 14 mm) sizes were used for the project and its composition was analyzed with the UV-VIS spectrometer before carburization. The tools were carburized with pulverized carbon (Palm Kernel Shell) using 25 % Barium trioxocarbonate (V) as an energizer in a muffle treatment furnace of about 1500oC. The performance evaluation of the tool was done by measuring its wear volume, wear resistance, weight loss and wear rate on all the samples (treated and untreated) using Rotopol –V. Minimum wear rate of the tool was 1.095 X 10 -8 cm2/N at carburizing temperature with time of 950oC and 120 minutes, 2.190 X 10 -8 cm2/N at 800oC and 60 minutes while those of the control sample ( untreated) was 1.127 X 10 -8 cm2/N. It can be concluded that the carburized tool has a lower wear rate at high carburizing temperature with time over at low carburizing temperature with time and control (untreated sample) in the tests carried out. The result of the performance evaluation tests corroborated the higher qualities of the carburized cutting tool at high temperature with time over others

Impacts of Carburizing Temperature and Holding Time on Wear of High Speed Steel Cutting Tools.

The paper presents a report on effects of variation in carburizing temperature and time on cutting tool to enhance its use in engineering applications. 30 pieces of HSS cutting tools (200 x 14 x 14 mm) sizes were used for the project and its composition was analyzed with the UV-VIS spectrometer before carburization. The tools were carburized with pulverized carbon (Palm Kernel Shell) using 25 % Barium trioxocarbonate (V) as an energizer in a muffle treatment furnace of about 1500oC. The performance evaluation of the tool was done by measuring its wear volume, wear resistance, weight loss and wear rate on all the samples (treated and untreated) using Rotopol –V. Minimum wear rate of the tool was 1.095 X 10 -8 cm2/N at carburizing temperature with time of 950oC and 120 minutes, 2.190 X 10 -8 cm2/N at 800oC and 60 minutes while those of the control sample ( untreated) was 1.127 X 10 -8 cm2/N. It can be concluded that the carburized tool has a lower wear rate at high carburizing temperature with time over at low carburizing temperature with time and control (untreated sample) in the tests carried out. The result of the performance evaluation tests corroborated the higher qualities of the carburized cutting tool at high temperature with time over others

Casting and Performance Evaluation of Pump Impeller and Housing using Local Raw Materials

Casting of pump impeller and its housing was carried out using locally available materials. Performance evaluation was conducted to show if the locally produced pump impeller and its housing could be compared favourably in terms of performances with the imported ones. The sand used for the moulding of the pump housing and impeller was blended in the sand mixer with bentonite, wood dust, water and others as desired in their correct proportions (Bentonite-3.5%, Water 3.5%; Wood dust 4.2%). Pouring of the molten metal unto the assembled mould was done at a temperature of about 1380oC.  Portable optical pyrometer was used to measure the temperatures.  The charge make ups was 135kg of cast iron scraps, 0.58% FeSi, 0.035% Femn and 0.0045% Inoculants.   Replica of the two components were carefully produced in wooden patterns to make the sand mould easy, while the casting was made using grey cast iron because of the need to machine it to its final dimensions with ease. The results obtained from the various test carried out shows no significant difference from the standard result of the imported ones

Production of Cutting Tools from Recycled Steel with Palm Kernel Shell as Carbon Additives

Machining is an integral and indispensable part of production technology with cutting tool playing key roles in its operations. This work therefore developed cutting tool from scrapped crank shaft, connecting rod, alloy additives and palm kernel shell. These materials were chosen due to their hardness and availability. The scrapped crankshaft and rod (100 kg) containing 0.560 % carbon were charged into electric induction furnace with maximum temperature 3000oC. The composition of the charged materials was analyzed with the UV-VIS spectrometer before and after melting. In order to raise the carbon content of the melt to 0.65% target (HSS) and upgrade relevant elements, alloy additives were added. Annealing was the first treatment carried out in muffle treatment furnace at temperature at 900oC for 9 hrs then cooled to 300oC. The annealed materials were machined into 20 pieces of long (199 x 12 x 12 mm) and short (20x 12 x12 mm) sizes. Further treatments of hardening, normalizing and tempering were also carried out on the cutting tools. The tools were then carburized with pulverized carbon using 20 % Barium trioxocarbonate (V) as an energizer in a muffle treatment furnace. Each of the samples was soaked at temperature of 800oC, 850oC, 900oC and 950oC for 60, 90 and 120 minutes holding time. Microhardness and surface hardness of the tool were 47.9 and 76.8HR, while for control sample were 46.1 and 76.3HR respectively

Modeling and Simulation of Wave load on Periodic Support for Isolation system of offshore platform.

The wave-induced dynamic load is one of the most important excitations to be dealt with in the design of offshore structures and the platforms. In order to perform a reliable design of an offshore structure, it is important to obtain an exact evaluation of its dynamic response to wave load but also to examine the ways of reducing the response. The work analyzed the effects of wave load on periodic support of isolation system of jacket offshore platform. The platform considered herein as an example to examine the effectiveness of the proposed vibration control strategy for offshore structures. In this section, a parametric study for the jacket offshore platform with installation of the periodic support to enhance isolation system due to its attenuations ability over broad frequencies and the effects of wave load on offshore jacket platforms installed with energy dissipation devices such as periodic support were presented. The offshore jacket platforms are modeled as multi-degrees-of-freedom and the general equation for fluid forces acting on a cylinder, considering the relative motion of the body in the fluid as per the Morison’s equation was applied to form the basis of modeling of the wave load and supports. The analyzes of the effects of wave load on the offshore platform especially with periodic support was considered due to its attenuations over broad frequencies. It could be realized from the result that increase in waves load varies the increase in frequency domain of the system which enhances subjection to vibration

EFFECTS OF CARBURIZATION ON MECHANICAL PROPERTIES OF RECYCLED STEEL WITH PERM KERNEL SHELL (PKS) AS CARBON ADDITIVES.

The prediction and control of wear is one of the most essential problems emerging in the design of cutting operations which has to be checked through local production. This work therefore studies the effects of carburization on mechanical properties of recycled steel with Perm Kernel Shell (PKS) as carbon additives. 40 pieces of recycled Steel tools were used for the project. The tools were carburized with 40 kg of pulverized carbon of Perm Kernel Shell using 30 % Barium trioxocarbonate (V) as an energizer in a muffle treatment furnace of about 1500oC. Each sample was held at temperature of 800oC, 850oC, 900oC and 950oC for 60, 90 and 120 minutes holding time. The performance evaluation of the tool was done by using the tools (carburized and un-carburized) to machining low and medium carbon work piece on the lathe machine and also measured its impact/toughness using impact tester. The results shown best cutting performances and toughness in carburized tool of higher impact/ toughness value of 24 J over control sample of 17 J. The result of the performance evaluation tests corroborated the higher qualities of the carburized cutting tool over un-carburized type

Development of Material Selection Software for Airplane Construction

Software named CAMSPlane was developed to implement the material selection strategy for airplane structure using rule based reasoning approach. The rule-based system is flexible, powerful and more applicable for domains where the possible solutions are either unbounded or large in numbers (Sapuan, 1999). The challenge of evaluating adequate technique for selection of optimal materials was solved in respect to the available expert knowledge and experience (Adejuyigbe, 2007). The software was designed to enable material data to be accessed through graphical user interface. It consists of an inference engine and knowledge base. The software was developed using Visual Basic 6.0 programming environment; designed to be interactive, user friendly and to run on Microsoft windows environment. The developed software can be updated or edited to suit other applications

Data showing the effects of temperature and time variances on nano-additives treatment of mild steel during machining

The effects of temperature and time variances on nano-additives treatment of mild steel during machining was presented in this study. Mild steel of 150 kg mass containing 0.56% carbon was charged into the furnace at melting and pouring temperature of 1539 and 1545 °C respectively. Also charged into the furnace with the mild steel were 0.05% max phosphorous and a bit of sulphur. Thereafter, the sample was cooled and annealed at a temperature of 900 °C for 9 h and then cooled to 300 °C of hardening, normalizing and tempering respectively. The treated samples were then soaked with pulverized in palm kernel shell and barium carbonate (20%) energizer at respective temperatures (800, 850, 900 and 950 °C) and time variances (60, 90 and 120 min) in a muffle furnace. The developed tool was tested on a lathe machine to evaluate its performance. The surface and core hardness, wear resistance and toughness were carried out using the hardness tester, Rotopol–V and impact tester respectively. This is essential for predicting the useful life of the tool in service. Keywords: Nano-additive, Medium carbon steel, Case-hardening, Machinin

Data showing the effects of temperature and time variances on nano-additives treatment of mild steel during machining

The effects of temperature and time variances on nano-additives treatment of mild steel during machining was presented in this study. Mild steel of 150 kg mass containing 0.56% carbon was charged into the furnace at melting and pouring temperature of 1539 and 1545 °C respectively. Also charged into the furnace with the mild steel were 0.05% max phosphorous and a bit of sulphur. Thereafter, the sample was cooled and annealed at a temperature of 900 °C for 9 h and then cooled to 300 °C of hardening, normalizing and tempering respectively. The treated samples were then soaked with pulverized in palm kernel shell and barium carbonate (20%) energizer at respective temperatures (800, 850, 900 and 950 °C) and time variances (60, 90 and 120 min) in a muffle furnace. The developed tool was tested on a lathe machine to evaluate its performance. The surface and core hardness, wear resistance and toughness were carried out using the hardness tester, Rotopol–V and impact tester respectively. This is essential for predicting the useful life of the tool in service. Keywords: Nano-additive, Medium carbon steel, Case-hardening, Machinin