Volume 27, No. 4 (2021)
Articles
UTILIZATION OF POLYPROPYLENE IN BITUMINOUS CONCRETE
EZEMENIKE CHUKWUKA(1*) , OLADELE ISIAKA(2), ADERINLEWO OLUFIKAYO(1), OYEDEPO OLUGBENGA(1)
The utilization of polypropylene in form of waste plastic to produce bituminous concrete for pavement construction was studied. The aggregates, bitumen and polypropylene were characterized. Bitumen was partially replaced with polypropylene at 2, 4, 6 and 8% by weight to produce asphalt concrete, thereafter, Marshal Stability and flow test was carried out on asphalt concrete. From the result, Marshal Stability values of 8.77, 9.18, 9.5 and 11.51 KN while flow values of 3.5, 3.2, 3.1 and 2.8 mm were respectively obtained. This study suggests that the polypropylene could enhance the performance of asphalt concrete and decrease the cost of road construction.
ASPECTS REGARDING THE ENERGITICAL VALORIFICATION OF URBAN SLUDGE TREATMENT
DANA-CLAUDIA FARCAȘ-FLAMAROPOL(1), ELENA SURDU(*1), ION DURBACĂ(1), ANDREEA NIȚU(1), RAMONA MARE(1), EUGEN DUȚU(2)
This paper highlights through the issues addressed, the application aspects regarding the approach of the concept of recovery of sewage sludge from an urban wastewater treatment plant (SEAU), which is in a stage of technological expansion and modernization. Thus, it is considered the need to process the potential of biological mass generated by anaerobic stabilization in the SEAU, with a population of about 10,000 equivalent inhabitants, which requires on one hand, the technological design of activated sludge basins and on the other hand, the design of a sewage sludge fermentation tank, in order to produce biogas, necessary for its recovery for energy purposes.
STRETCH FORMING USING HEATED DIE
COSMIN CONSTANTIN GRIGORAȘ*, BOGDAN CHIRIȚĂ, VALENTIN ZICHIL, EUGEN HERGHELEGIU, CĂTĂLIN TÂMPU, VLAD CIUBOTARIU
The stretch forming process implies stretching and drawing into shape a sheet of material onto a die. This method is used, among other sectors, in the construction of aeroplane fuselage, as significant, complex parts can be obtained in one piece. In essence, stretch forming implies working with materials that have medium to high spring back effects, such as aluminium or magnesium alloys. Different approaches are used in manufacturing due to this phenomenon, ranging from incremental processes to multipoint dies. Another critical aspect of this process is to know how the material behaves under severe plastic deformation, as different alloys require different approaches that vary from step by step forming to in-process chemical treatments to manual pounding the metal sheet. However, all these alloys have in common that, when heated, their machinability properties improve. In this experimental study, a heated die approach was taken into consideration. 6x60 mm 100W heating elements along with temperature sensors were fitted into the die. The USB/OC326009 metal sheet is in direct contact with the die, thus assuring the heat transfer, as the temperatures reach 200 °C. The die temperature is software controlled so that maximum temperature and thermal inertia could be controlled with ease. The data indicate that this method offers significantly improved results compared to a normal room-temperature process.
EFFECT OF SOLUTION pH AND TEMPERATURE ON PHENOL ADSORPTION ONTO CARBONIZED RICE HUSK CHEMICALLY ACTIVATED WITH PHOSPHORIC ACID
YAHAYA S. MOHAMMAD(*1,3), MOHAMMED U. GARBA(2), MUHAMMAD A. MUHAMMAD(3), YAKUBU AZEH(3), SULEIMAN Y. BAGIREI(1)
Operating conditions such as pH and temperature are important factors that influence the performance of activated carbon and solute uptake in adsorption process. Thus, this research work was aimed at studying the effect of solution pH and temperature on phenol adsorption onto rice husk activated carbon. Results obtained showed that when pH was increased from 2 to 4, adsorption capacity and removal efficiency increased, and thereafter, decreased progressively with additional increase in pH. Results also showed that when temperature was increased from 30 to 50 oC adsorption capacity and removal efficiency decreased. Therefore, this study has established that the optimum solution pH for adsorption of phenol onto phosphoric acid modified rice husk activated carbon is 4, and better performance of the adsorption process was occurred at lower solution temperatures.
INFLUENCE OF THE CRANK MECHANISM POSITION IN THE MOTION OF AN OSCILLATING SIEVE
EMILIAN MOSNEGUTU(1), NARCIS BARSAN(1), MIRELA PANAINTE-LEHADUS(1), DANA CHITIMUS(1), CLAUDIA TOMOZEI(1*)
This article presents a study that aims to visualize the influence exerted by the position of the crank mechanism on the motion performed by the sieve supports respectively, on the displacement of an oscillating sieve. The study was oriented for a specific constructive case and involves the connecting rod position changing, the drive mechanism in relation to the horizontal, respectively at the angles 0 - 75 and -45 - 0. Also, were identifying the variation of the angle described by the motion of the sieve support. From the obtained results analysis, it was found that in the case of 12.71 of the connecting rod angle, in relation to the horizontal, the lowest value of the angle described by the motion of the tie rod between the extreme points was obtained. Also, for the value of the connecting rod angle of approximately 6.5 equal angles described by the extreme positions of the sieve support in relation to the vertical were obtained. It is found that the variation of the connecting rod angle directly influences the variation of the angles described by the connecting rod in relation to the horizontal, the measured value being corresponding to the extreme points P1 and P2.
ERGONOMICS AND FUNCTIONAL REQUIREMENT IN THE DESIGN OF STUDENTS’ FURNITURE IN MOSHOOD ABIOLA POLYTECHNIC ABEOKUTA NIGERIA
ADEKUNLE IBRAHIM MUSA-OLOKUTA*
A total of five hundred and fifty students were randomly selected in three schools of engineering; communication; science and technology. The existing furniture dimensions were measured. The maximum and minimum table height was determined. The results showed seat heights as compared with the students body sizes are expected to be in the range of 33.85 cm and 36.54 cm. Table height is expected to be in the range of 61.08 cm and 64.48 cm. The study concluded that data on the anthropometric dimension of students are provided and this could be used as database for the planning of future furniture in the lecture rooms.
TOTAL SUSPENDED PARTICULATES FROM CRUDE OIL SPILL
OYETUNJI BABATUNDE OKEDERE(1*), ADEWOLE JOHNSON ADESANMI(2), JACOB ADEMOLA SONIBARE(3), OLUSOLA ADEDAYO ADESINA(4), GBADEBO OMONIYI ADENIYI(5)
Total suspended particulates emitted during crude oil spill were investigated using laboratory simulation experiments. This was with a view to establishing the toxicity potentials of emitted particulates. Climatic and spill media conditions similar to those obtainable in real life were created in an environmental chamber and the total particulates emitted during spills involving three crude oil samples of Nigerian origin were measured with Quick Take sampler. The toxicity potentials of the emitted particulates were subsequently determined by dividing the 24- hour averaging period concentrations of the particulates by the statutory limit. The statutory limits used were those of Nigeria’s Federal Ministry of Environment (FMENV), World Bank and the World Health Organization (WHO). For temperatures between 15 ºC and 35 ºC and spill media (over fresh water, sea water and soil), the extrapolated 24 – hour averaging period concentrations ranged between 186.79 – 584.28 μgm-3, 186.98 - 584.48 μgm-3 and 247.40- 350.21 μgm-3 for sample A; 183.44 – 571.99 μgm-3, 183.63 -572.19 μgm-3 and 244.05-337.92 μgm-3 for sample B and 178.41 – 566.96 μgm-3, 178.61 - 567.16 μgm-3 and 332.89- 280.60 μgm-3 for sample C. The observed TSP concentrations breached the WHO (lower limit) and World Bank limits at all temperatures and over all spill media and consequently the toxicity potentials exceeded 1.0 which were indications of hazards to human health. The study concluded that particulate emissions during crude oil could be high enough to pose threats and suggested adequate protection for cleaning up workers.
MANAGING SUPPLY CHAIN RISKS: A FUZZY-FAILURE MODE AND EVALUATION APPROACH FOR RANKING THREATS
AYODELE OLUWASEGUN OLUWOLE(1), BABATUNDE OMONIYI ODEDAIRO(1*), VICTOR OLUWASINA OLADOKUN(1)
On the backdrop of lower transportation cost, outsourcing paved the way for borderless production activities and ushered in the era of Supply Chain Management (SCM). For many organizations, achieving the goals of their Supply Chain (SC) is constantly threatened by increased competition and disruption. In this study, the aim is to identify, and rank, SC threats in a developing country using Failure Mode and Effects Analysis (FMEA) with Fuzzy Logic (FL). FMEA parameters were derived for 44 supply chain threats (SCT1 – SCT44) and their Risk Priority Number (RPN) determined. Subsequently, the Mamdani Fuzzy Inference system was utilized to arrive at a Fuzzy-RPN with 125 rules using severity as a determining factor. The rules were ranked to prioritize SC threats. From the conventional FMEA, demand variation (SCT42) and long-distance sourcing (SCT27) had the highest and lowest RPN, respectively. After fuzzification and defuzzification, Fuzzy-RPN identified raw material delay (SCT1), government policy (SCT11), poor transport infrastructure (SCT18) and political instability (SCT19) as threats with the highest Fuzzy-RPN (210) and product recalls (SCT28) with the lowest Fuzzy-RPN (99). Based on these results, it is concluded that a Fuzzy-FMEA approach can identify and rank SC threats with the use of an RPN devoid of sentiments and inaccuracies.
SOCIAL AND ERGONOMIC EVALUATION OF MOTORCYCLE PROTECTIVE ISOLATION SHIELD FOR REDUCING COMMUNITY SPREAD OF COVID-19
OLUKAYODE O. OYESIKU(1), OLASUNKANMI O. AKINYEMI(2), BASHIR O. ODUFUWA(3), BABATUNDE O. ADETIFA (4*)
Coronavirus (COVID-19) pandemic have rapidly evolved into a situation with profound effects on lifestyle and travel worldwide, ranging from a dramatic decrease in the patronage of formal public transport modes to an unprecedented increase in the usage of informal public transport modes. It is the main goal of this study to adapt a Motorcycle Protective Isolation Shield (MPIS) on a motorcycle for the reduction of community spread of COVID-19. MPIS was designed according to the anthropometry data obtained from motorcycle riders and passengers; and was fabricated using locally available materials. Anthropometry data used for the MPIS frame were sitting height (SH) and popliteal height (PH) of both motorcycle riders and passengers while seat depth (SD) of motorcycle riders and buttock knee length (BKL) of motorcycle passengers were used to locate the position of the MPIS mounted on the motorcycle. The 50% of the anthropometry data used for the design of MPIS is SH=800.00 mm, PH=500.00 mm, SD=300.00 mm and BKL=550.00 mm. The uncertainty modelling of motorcycle accident occurrence reveals the effect of higher speeds and the adapted MPIS during riding. The probability of occurrence of fatal crash, major crash and minor crash of motorcycle accident was 36.3%, 35.3% and 28.4%, respectively. The MPIS showed satisfactory post-riding assessment in terms of riding stability; riding, steering, and sitting convenience; and riding comfort for both the riders and passengers. It will be a good protection for motorcycle riders against the risk of COVID-19 and other air-borne infections.
DEVELOPMENT OF AN IMPROVED DATABASE FOR YORUBA HANDWRITTEN CHARACTER
OLUWASHINA O. OYENIRAN(1), JOSHUA O. OYENIYI(2*), LAWRENCE O. OMOTOSHO(2), IBRAHIM K. OGUNDOYIN(2)
For improved human comprehension and autonomous machine perception, optical character recognition has been saddled with the task of translating printed or hand-written materials into digital text files. Many works have been proposed and implemented in the computerization of different human languages in the global community, but microscopic attempts have also been made to place Yoruba Handwritten Character on the board of Optical Character Recognition. This study developed a novel available dataset for research on offline Yoruba handwritten character recognition so as to fill the gaps in the existing knowledge. The developed database contains a total of 12,600 characters being made up of 70 classes from a total number of 200 writers, in which 80 % (10,500) is regarded as the training and validation dataset while the remaining 20 % (2,100) is regarded as testing dataset. The dataset is available on https://github.com/oluwashina90/Yoruba-handwritten-character-database. Hence, it is the complete and largest dataset available for Yoruba Handwritten character research.
UNCONVENTIONAL TECHNIQUE USED TO MANUFACTURE POROUS HIGH-STRENGTH GLASS FOAM
LUCIAN PAUNESCU(*1), SORIN MIRCEA AXINTE(1,2), MARIUS FLORIN DRAGOESCU(2), BOGDAN VALENTIN PAUNESCU(3), FELICIA COSMULESCU(4)
The paper presents experimental results obtained in the manufacturing process of porous high-strength glass foam for thermal insulation in buildings made of glass waste and kaolin clay as raw materials and dolomite as a foaming agent. The paper’s originality is the use of the unconventional microwave heating technique. The best product manufactured by this technique was that sintered at 1050 ºC using 18 wt.% kaolin clay and 3.5 wt.% dolomite. The product characteristics were: the apparent density of 0.66 g·cm-3, the thermal conductivity of 0.155 W/m·K, the compressive strength of 5.3 MPa and a microstructural homogeneity with pore size between 0.20-0.50 mm.