40 research outputs found
Effect of Heat Treatment on Microstructure and Mechanical Properties of SAE 1025 Steel: Analysis by one-way ANOVA
The effect of heat treatment at 850oCon the microstructure and mechanical properties of SAE 1025 carbon steel has been studied. Annealing, normalizing and age-hardening heat-treatments at 850oC were used for the experimental work. Hardness tests, tensile tests and metallography were carried out on the heat-treated and control samples. The results were further analyzed using the one-way ANOVA test. Results obtained showed significant differences in the microstructure and mechanical properties of the different heat-treated samples. The hardness profile determined using a Brinell ball indenter showed decrease in hardness of the heat-treated samples when compared with the control. A microstructure of enhanced quality was obtained with normalizing heat-treatment. A higher tensile strength of 313.55MPa was obtained with annealing heat treatment in comparison to age-hardening (212.94MPa), normalizing (167.79MPa) and the control test (269.12MPa). ANOVA test confirmed the results at 90% confidence and further showed that there was significant difference amid the four test conditions
Energy and Cost Analysis of Cement Production Using the Wet and Dry Processes in Nigeria
The study evaluates the energy consumption of both wet and dry processes cement manufacturing plant in Nigeria. En- ergy consumption data collected for the period 2003 to 2011 were used to estimate the energy consumption of the crushing, milling, agitation, burning, grinding and bagging operations. The total energy evaluation was based on the three primary energy sources which include electrical, combustion and human. The total estimated energy intensities were 6545 MJ/ton and 4197 MJ/ton for wet and dry processes respectively. The percentage consumption of energy in each operation is 93.68 and 90.34% (burning), 2.11and 4.33% (milling), 0.43 and 0.67% (crushing), 1.39 and 0% (agi- tation), 2.12 and 3.90% (grinding), and 0.27 and 0.75% (bagging) of the total energy inputs for the wet and dry proc- esses respectively. Furthermore, the average total energy cost of production showed that wet process is approximately 40% more cost intensive in cement production than the dry process while at the same time it is cost effective to run production on energy through gas powered plant than the national grid
Quality Improvement of Foundry Operation in Nigeria Using Six Sigma Technique
In this paper Six Sigma DMAIC analysis was applied in an aluminium mill in order to identify sources and causes of
waste with the intention of providing veritable solutions. The foundry section was the segment under scrutiny. Re-work
or defects in this firm was found to be on the average of about 37.05% of total production for the twenty-three months
under study (January 2009- December 2010). Defect reduction was therefore chosen as the Critical-to-Quality (CTQ)
factor. The sigma level of 1.87 in the firm indicated the existence of opportunities for improvement. Analysis was carried
out using SPSS, SPC for Excel to perform regression analysis, process capability analysis, generate descriptive statistics,
histograms and run charts. The results of these analyses identified three major defects and some of their behaviours.
Based on the analysis, solutions were proffered in the Improve and Control phases of this project. Implementation of the
proffered solutions resulted in noticeable improvement and led to the firm operating with near- perfect processes thus
proving the applicability of Six Sigma
Study of the Corrosion Inhibition Reaction of Admixed Plant Distillates on Mild Steel
The corrosion inhibition reaction of plant distillates and their synergistic combination effect was
studied. Atlas cedarwood distillate (ACW), and admixture of sage and Jojoba distillates (SJA), and
admixture of jojoba and lavender distillates (JLD) were evaluated at minimal concentrations to for
their corrosion inhibition effect on mild steel in 1 M H2SO4 solution. Results showed ACW reacted
poorly at 1% and 2% inhibitor concentration. However, from 3% - 6% ACW concentration the final
corrosion rate of 94.73%, 94.77% and 95.61% was attained at 240 h signifying effective inhibition
performance. SJA inhibitor compound exhibited optimal performance at all concentrations (1% - 6%
SJA) with maximum inhibition value of 98.44% at 5% SJA concentration. JLD exhibited optimal
performance at all concentrations studied after 2% JLD with maximum inhibition value of 91.07% at
3% JLD concentration and 240 h exposure time. The mean values for ACW and JLD inhibition
efficiency appreciated with increase in inhibitor concentration while the value for SJA compound was
generally constant. Results shows the extent of variation from mean values (standard deviation) for
ACW and JLD was significantly high compared to the values obtained for SJA compound where the deviation from mean value is below 2. The Margin of error values for ACW and JLD compound
shows that 65% and 60% of inhibition efficiency data have values above 70% inhibition efficiency
compared to SJA where 100% of its inhibition efficiency data have values above 70% inhibition at
+12.07%, +13.58% and +0% and +13.58%. Statistical analysis ANOVA only inhibitor concentration
of the compounds significantly influenced their inhibition performance with values of 66.61%, 70.29%
and 93.07% (ACW, SJA and JLD compound) compared to exposure time which had no influence.
However, confirmation comparison of the mean square ratio of the compounds with the theoretical
statistical tables shows the inhibitor concentration for JLD only is statistically relevant
The Role of Research in Economic Development
This study channels via the association between analysis utilizations, and financial advancement at the national level in creating country. Innovative works are basic driving advancement, national improvement and financial development, yet there likewise should be objective will to succeed. There must be a solid collaboration amongst the scholarly world and the industries. At the same time,
hypothetical, as well as experimental writing has radically demanded that the thing of interests in examine is an irreplaceable part of economic development. The
affiliation between inquire about uses and monetary execution has pulled in a lot of consideration in the scholastic field for a long while. Notwithstanding that, the
subject has been for some time stressed by governments and private undertakings. The vast majority of the modern financial experts have ascribed the sustained
development in developingnations to their escalated inquiresin research works. The dialog of the connection between economic development and research expenses has
an uncommon direness, for instance Turkey's aspiring financial targets. The emphasis on human capital as a driver of economic development for developing nations has prompted undue consideration on school accomplishment. Developing
nations have made impressive advance in shutting the hole with regarding school accomplishment, yet ongoing exploration has underscored the significance of
subjective aptitudes for economic development. This outcome shifts regard for issues of school qualityaround the developing nations has been significantly less
fruitful in shutting the holes. Without enhancing school quality, developing nations will think that it is hard to enhance their long run financial performance. This paper
exposes the impact of research in economic development of developing nations where it is taken in high-regard, shows where research has taken them to, influencing their GNP, NDP, new inventions, established standards
Corrosion inhibition and statistical data of low carbon steel in HCl media by admixed organic compounds
Corrosion inhibition of carbon steels with organic compounds exhibiting effective
corrosion inhibition is an on-going research. The corrosion inhibition of low carbon steel in 1M
HCl solution by the combined admixture of vanillin and benzonitrile (VBN), and salvia
officinalis with lavendulan officinalis (SLV) was studied by weight loss method. Results
obtained show that VBN and SLV performed effectively with maximum inhibition efficiency
91.03% at 1.5% VBN concentration and 97.89% at 5% SLV concentration. The inhibition
efficiency of VBN increased with concentration but decreased with exposure time compared to
the values obtained for SLV which showed non-dependence on concentration and exposure time
after 1% SLV concentration. Correlation plots of inhibition efficiency versus inhibitor
concentration show VBN to be more concentration dependent in performance. Calculated data
for standard deviation shows the degree of variation from mean values for both compounds is
significant at low inhibitor concentration due to time dependence action. Statistical analysis
through ANOVA shows inhibitor concentration overwhelmingly influences the inhibition
performance of the despite even though exposure time is statistically relevant to minimal degree
Design and performance evaluation of centrifugal cashew nut sheller for improving the whole kernel recovery
Cashew nut centrifugal shelling machine was designed and constructed. Shelling efficiency and whole kernel
recovery were evaluated for hot-oil roasted nuts on the machine. The design was based on the principle of the optimum kinetic energy that could break the cashew nut shell. The deformation energy used was 4.8763 J. The angular velocity of the impeller calculatec! from the energy was 376.12 r s·1 which was equal 3592 r min-1• The motor power used was more than 9 17.34 W, the minimum power requirement. The prototype of cashew nut sheller was constructed and evljluated for its shelling efficiency (SE) and whole kernel recovery (WKR) using three levels of moisture content (7.00% w.b., 8.46% w.b. and 9.83% w.b.), three levels ofirnpeller speeds and three grades (large, medium and small) of nut sizes. The results showed that the moisture content had a significant effect (at P<0.05) on the SE and WKR for all the grades of the nut. However, the impeller speed has a significant effect on the whole kernel recovery of medium and small nuts. The predicted optimal values of the WKR and SE for large nut were 65.4% and 96.8% respectively at 3110 r min-1 and 9.06% w.b. For medium nut, they were 51.62% and 93 .24% respectively at 3487 r min-1 and 8.92% w.b. For small nut, they were 37.95% and 92.56% respectively at 3487 r min-1 and 9.83% w.b
A Study on Energy Demand and Consumption in Covenant University, Ota, Nigeria
In this study, ene•·gy audit was conducted at
Covenant Unive•·sity to assess the pattem of elect.-icity
consumption in m·de•· to imp.-ove ene•·gy consumption
efficiency in the Unive.-sity. Space cooling (29%) and
lighting (29%) have the highest pe1-centage elect.-icity
consumption in the unive•·sity. In the academic buildings,
maximum powe•· is consumed in space cooling (49%). In the
staff quaJ-te•·s, lighting application consumed maximum
powe•· (39%), followed by space cooling application (18%).
The annual ene•·gy and cost saving potentials fm· •·eplacing
t.-aditional flum·escent tube lights (FTLs) and incandescent
bulbs with compact fluo•·escent lamps (CFLs) in the
students' hostels and in the staff quaJ-te•·s a1·e about 394
MWh, N4.8 Million (49, 375) •·espectively. Fm· space cooling systems, the
annual ene•·gy and cost saving potentials fm· •·eplacing
conventional •·esistance elect.-ic •·egulato•· fans with
elect.-onic •·egulatm· fans is about 367 MWh and N 9.8
Million ($61,250), •·espectively
Assessment of Energy Saving Potentials in Covenant University, Nigeria
In this study, an energy audit was conducted at Covenant University in Nigeria looking for ways to reduce energy costs. Results show that of the total university electricity energy demand, space cooling and lighting have the highest electrical consumption (29%). In academic buildings, space cooling consumed the maximum power (49%), while lighting consumed the most power (39%) in staff quarters. Annual energy and cost savings for replacement of traditional fluorescent lights(FLTs) and incandescent bulbs with compact fluorescent lamps (CFLs)in student hostels and staff quarters are about 394 MWh, N4.8 million (49, 375) respectively. Consequently, for space cooling systems, the annual energy and cost savings for replacement of conventional resistance electric regulator fans with electronic regulator fans is about 367 MWh and N 9.8 Million ($61,250).A well-articulated and vigorously pursued energy efficiency policy measures in the university can result in an estimated annual savings in electricity consumption of about 16%
Material efficiency: a key sustainable manufacturing strategy
Inefficient material utilization results in extra pressure on the environment for the extraction
of more material to meet production demand and therefore makes the environment unsustainable. The
survival of the manufacturing industry depends on its ability to balance several requirements to meet up
with dynamic market demand particularly materials for production ranging from raw materials,
intermediate materials to spare components for maintenance. In the past, sustainability and efficiency
were no challenges to the manufacturers and material extraction from the environment was always below
replenishment. Presently, the reverse is the case where the demand for production material has become
incessant and surpasses supply on account of increasing population and modern manufacturing practices
thereby resulting in irresponsible exploitation of raw material. This paper aims to evaluate the current
efforts in the topic area to gain insight into the impact of material efficiency on the manufacturing
performance concerning other manufacturing strategies alongside the environment. It appears from the
review that the balance between manufacturing material extraction from the environment and the
replenishment rate determines the sustainability of both the manufacturing system and the environment.
Hence material efficiency is an index for sustainable manufacturing strategy. We recommend the future
research direction to looks into the development and determination of balance between manufacturing
material extraction from the environment and the replenishment rate for a sustainable future manufacturing