Arid Zone Journal of Engineering, Technology and Environment (AZOJETE)
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Evaluation of the Influence of Ground Wastes Glass on Mechanical Properties of High Performance Concrete
Get PDFThe construction industry is largely reliant on the use of cement-based products. Every tonne of ordinary Portland cement (OPC) emits equivalent amount of CO2 into the atmosphere, contributing to increased raw material consumptions and environmental concerns. In this regard, the use of waste materials that can be blended with OPC as partial or full replacement to reduce the environmental impacts is strongly desirable. This research was experimentally carried out to evaluate the influence of ground waste glass (GWG) as a partial replacement of cement in high performance concrete (HPC). A grade 50 HPC was designed based on ACI 211.1-91. Various experiments were carried out to determine the mechanical properties of the HPC. Tests include specific gravity of constituent materials, sieve analysis of GWG and aggregates, slump flow of fresh HPC, compressive, splitting tensile and flexural strengths of hardened HPC were carried out. The chemical composition analysis of GWG was conducted using X-Ray Fluorescence (XRF) analytical method. HPC cubes, cylinders and beams were cast, cured and tested at curing ages of 3, 7, 28, 56 and 90 days using 0, 5, 10 15, 20 and 25 percentage replacement levels. The optimum compressive strength of 57.44 N/mm2 was obtained at 10% cement replacement after 28 days of curing age. The slump test result shows that the workability of the HPC decreased as the GWG content increases. Generally, the strengths of HPC reduced as the percentage of GWG replacement increased beyond 10% but increases with curing age. Therefore, 10% is the optimum replacement level of GWG for cement in HPC.
 
Corrosion of Aluminium Metal in Food Environments and its Associated Health Risk Issues: A Review
Get PDFA material for use in contact with food must have adequate strength and integrity to avoid its accidental fracture and leaching of pernicious substances into the food due to corrosion or abrasion of the material. This review covers the basics of aluminium metal and its corrosion in food-handling usage and the associated health-risk issues of its particle intake by human food consumers, as well as current research on the topic. The review findings show that aluminium metal has outstanding advantages in food handling in terms of low cost, wide availability, light weight, ability to heat and cool fast, high temperature tolerance, good corrosion resistance, and perennial shiny appearance in unpolluted natural environments. Its other advantage is excellent formability into designed kitchenware shapes. On the other hand, the findings show that aluminium metal has lower strength and hardness integrity. It is also leachable with lower health-safety level for food-handling usage compared to many other food-grade metals such as stainless steel. Furthermore, daily intake of aluminium substances above 10 mg per kilogram by an individual is risky to their health. The other findings are that food environments with high chloride, acidity, and alkalinity contents can cause greater corrosion of aluminium metal to leach its particles into food, with a higher chance of intaking the particles into the human body system than other food environments. Finally, the findings show that only appropriately alloyed and adequately coated aluminium of sufficient strength should be used in contact with food. The information from the review is meant to serve as a consolidated current literature position on corrosion in the use of aluminium metal for food handling and associated health-risk issues for safe-guarding or a way forward by researchers and stakeholders that need background information for making the metal safer for food handling
An Automated Prototype System for Alcohol Level Detection in Drunk Drivers and Vehicle Control.
Get PDFDrunk driving is one of the principal contributors to road accidents in Nigeria. Passengers, other motorists and the driver's life are all at risk because of this behavior. The aim of this study is to develop a system that will automatically detects drunken drivers based on the proximity to the steering wheel and prohibits the car from been start. The method employed in this research is the use of an MQ-3 sensor to measure the level of alcohol in the driver's breath in the area around where the driver sits in a car and compare it to the Nigerian guidelines for acceptable blood alcohol concentration (BAC) levels. In addition, the alcohol sensor is protected from obstruction (coverage) by an MH infrared proximity sensor. Also, a red light alert is incorporated to sensitize the passenger whenever the driver is drunk. The result shows that the system performed satisfactorily. It prompt quicker reaction by prohibition of drunk drivers within a distance of 36 cm from the steering wheel from being able to start the car as well as sensitizes the passenger through blinking red light. It also prevent the systems sensor from been cover (obstruction) by drunk drivers within a distance of 5 cm. As a result, the system can be combined with the new technologies of modern vehicles to enforced don’t drive when drunk rules which are often violated by drunk drivers
Effect of Moisture Content on some Physical Properties of Red Kidney Bean (Phaseolus vulgaris L.) Seed Grown in North Eastern Nigeria
Get PDFThis study was aimed at determining some physical properties of red kidney bean seed as a function of moisture content. In the moisture range of 6.84-15.74% (d.b), seed length, width and thickness increased from 11.4-16.83mm, 6.2-8.87mm and 4.3-5.16mm, and Arithmetic and Geometric diameters increased from 8.6-10.29mm and from 8.3-9.14mm, respectively. In the above moisture range, one thousand seed weight, seed surface area, true density, and porosity increased linearly, while sphericity increased logarithmically, and angle of repose increased as a polynomial of the second order with moisture content. Bulk density decreased with increase in moisture content in the above moisture range. Static coefficient of friction on all the structural surfaces applied increased logarithmically with moisture content, and kinetic coefficient of friction on the surface all increased linearly with moisture content except on fiber glass where the increase was polynomial of the second order. Static and kinetic coefficients of friction were highest on Hessian bag material and lowest on fiber glass. Regression models that could be used to express the relationship between the physical properties and moisture content, with high coefficients of determination, were established. The data obtained in this study would be applicable in the design of red kidney bean seed handling and storage facilities.
 
Analysis and Evaluation of Energy Efficiency of 5G Networks in Wireless Communication.
Get PDFThis paper focused on the analysis and evaluation of energy efficiency of 5G networks in wireless communication. The projected rise in wireless communication traffic has necessitated high operating costs of conventional wireless cellular networks and scarcity of energy resources in low power applications. This paper examined different ways of deploying energy efficient hardware at the base stations in order to make the base station non-polluting energy. The method employed involves the measurement of power consumption at the macro cell and micro cell base stations. The results of the power consumption obtained from the macro cell base stations were used in three models, namely the Gex model, the modified Gex model and Ismail model for the periods of 0am – 1am, 12pm – 1pm and 11pm – 0am were 11228.63W, 11561.15W, 11231.06W, 12821.65W, 12983.29W, 12981.64W, 13020.56W, 15342.30W, 11323.83W, 11634.23W, 11374.37W and 13196.66W. Again, the results of the power consumption obtained from the micro cell base stations for the periods of 0am – 1am, 12pm – 1pm and 11pm – 0am were 717.09W, 754.83W, 729.65W, 748W, 723.67W, 743.34W, 717.6W, 741W, 643.5W, 667.74W, 642.9W and 718W, respectively. Therefore, it is concluded that the modified model produced energy consumption that are in consonance with the measured energy. Therefore, it is concluded that the modified Gex model produced energy consumption values which are in closed range with the measured energy values.
 
Evaluation of Groundwater Quality for Drinking Purposes using Water Quality Index, in Keffi Central Town of Nasarawa State
Get PDFIn Nigeria, access to fresh drinking water has become serious challenges to both rural and urban areas.The aim of this study was to evaluate groundwater quality in Keffi central town of Nasarawa State for drinking purposes using the water quality index technique. Eight groundwater samples (four from both boreholes and dug wells) were collected from the study areaduring the wet season in October 2019. The water quality index is a mathematical method used to facilitate water quality explanation. The pH, Electric Conductivity, Total Dissolved Solids, Total Hardness, Calcium, Magnesium, Sodium, Chloride, Sulphate and Bicarbonate were determined according to standard methods. pH ranged from 5.7 to 7.1(mg/l), Electric conductivity ranged from 256 to 1591(µs/cm), Magnesium ranged from 2.6 to 29(mg/l), Calcium ranged from 3.7 to 34(mg/l), Sodium ranged from 22 to 56(mg/l), Chloride ranged from 8.4 to 63(mg/l), Bicarbonate ranged from 54.3 to 219.6(mg/l), Sulphate ranged from 0.1 to 32.4(mg/l), Total Dissolved Solids ranged from 95.2 to 302.94(mg/l) and Total Hardness ranged from 23.8 to 204.23(mg/l). The water quality index obtained from different locations was found to vary from 44.32 to 61.60 for boreholes and 72.55 to 97.77 for dug wells. The results for the water quality index indicated that borehole locations 2, 4, and 8were safe for human consumption, while dug well locations 3,5,6 and 7were not suitable for drinking purposes, compared with Nigerian industrial standard drinking water. The reasons for the high water quality index values of some study areas were attributed to the lithological variation and anthropogenic activities in the region. Therefore, some of the well water required treatment such as demineralization
Inductance Calculation of Concentrated and Distributed Winding Synchronous Reluctance Motor Using Modified Winding Function Theory
Get PDFThis study evaluates the inductance characteristics of synchronous reluctance motors (SynRMs) with concentrated and distributed windings. Two methods based on Winding Function Theory (WFT) are used: the sinusoidal method and the actual winding function method. The actual winding function method, which considers spatial harmonics and actual geometry, is found to be more accurate. The study reveals that the distributed winding SynRM has a higher saliency ratio (2.10) compared to the concentrated winding SynRM (1.58), indicating better performance. These findings contribute to our understanding of SynRM inductance and can guide improvements in motor design and performance. The study also suggests avenues for developing more precise inductance calculation methods for SynRMs, enabling optimized motor performance.
 
Probabilistic Assessment of a Typical Reinforced Concrete Girder Under Critical Loading
Get PDFReinforced concrete bridges are continuously subjected to increased traffic load and exposed to harsh environments causing bridge members to deteriorate, thus, affecting their durability, safety and performance. This work aims at a probabilistic assessment of a reinforced concrete bridge girder under critical loading considering the flexural and shear failure modes of the bridge. A limit state function for the failure modes was generated and, the stochastic variables and statistical parameters were determined. Additionally, the safety indices for each failure mode were determined using First Order Reliability Method (FORM) procedure. Mathematical models were developed and the uncertainties in structural resistance, applied loading as well as structural components were included using the probabilistic method. A computer program in FORTRAN language was developed and deployed for the reliability analysis of the bridge girder to ascertain the level of safety using First-Order Reliability Method. The results revealed that the safety index for shear and flexural failure mode decreases as the span is increased. For concrete strength of 30 N/mm2 and a depth of 1000 mm, the safety index for shear and flexural failure reduced from 4.5 to 2.0 and 10.7 to 3.37 respectively as the span increases from 10 m to 19 m. This indicates that the shear and flexural failure modes are sensitive to increase in span. In order to obtain a minimum safety target of 3.8, it is recommended that the depth of the beam should not be less than 1200 mm while the span should not exceed 16 m, and concrete grade should not be less than 35 N/mm3.
 
Kinetics of the Valorization of Food Waste for Medium Chain Carboxylates Production; Effect of Ensiling and Inoculum source.
Get PDFHigher yields of medium chain carboxylates (MCC) can be obtained from the anaerobic fermentation of complex feedstocks like food waste if pretreatment preceeds fermentation. However, many conventional pretreatment processes produce inhibitors that could affect downstream processing in addition to increasing the cost of the overall process. In this study, ensiling was used as a cost effective and sustainable pretreatment method to instigate the formation of electron donors like lactic acid and ethanol in food waste for MCC production. Food waste was ensiled for 120 days and thereafter subjected to batch anaerobic fermentation using two different inocula including leachate and rumen fluid. Results show that ensiling degraded the cellulose and hemicellulose component of food waste and converted the water soluble carbohydrate content to lactic acid, acetic acid and ethanol. Ensiled substrates had a total MCC yield of 990.44 g/kgVS and 878.68 g/kg VS when leachate and rumen fluid was used as inoculum respectively, while the unensiled food waste had a total MCC yield of 522.80 g/kgVS and 430.88 g/kgVS when leachate and rumen fluid was respectively used as inoculum. In order to predict the MCC production, two kinetic models were used including the first-order model and the modified Gompertz model. Statistical indicators including the coefficient of determination, R2, the root-mean-square-error and the Akaike Information Criterion show that the first-order model predicted the experimental MCC better than the modified Gompertz model.
 
Investigation of Fresh and Hardened Behaviour of Nanostructured Concrete
Get PDFThe need for sustainable environment has triggered the deployment of supplementary cementitious materials (SCMs) which reduces the effect of carbon dioxide (CO2) emission emanating from cement production, as well as the cost implications. Cassava peel ash was adopted as a SCM but in a nanostructured form to investigate the properties of concrete. The experimental outcome of the compressive and splitting tensile strengths of nanosized cassava peel ash (NCPA)-cement concrete was presented in this paper. Materials employed for the concrete production were ordinary Portland cement, NCPA, river sand, granite chippings, and water. The compressive strength was obtained using 150 x 150 x 150 mm concrete cube specimens, while 150 x 300 mm cylindrical concrete specimens were used to assess the splitting tensile strength; both measured at 7, 14, 28, 56, 90 and 150 days of curing. The mixes were prepared for varying water cement ratios of 1.5% NCPA replacement intervals in a mix ratio of 1:1.5:3. The study revealed that the slump values increased as percentage of NCPA increased. The results showed that at a water-cement ratio of 0.75 and 19.5% NCPA replacement, the concrete attains excellent compressive strengths of 18.70 N/mm2, 22.10 N/mm2, 24.20 N/mm2, 30.10 N/mm2, 33.30 N/mm2, and 36.90 N/mm2 at 7, 14, 28, 56, 90 and 150 days respectively with 5.96 N/mm2, 7.04 N/mm2, 7.71 N/mm2, 9.60 N/mm2, 10.61 N/mm2, and 11.75 N/mm2 for splitting tensile strength. The results confirm the suitability and uniqueness of nanosization as adoption of NCPA enhances the properties of concrete in both the plastic and hardened states.