Global Journal of Engineering Research

Design and implementation of a digital thermometer with clock

Benjamin O. Akinloye, Aaron O. Onyan, Donaldson E. Oweibor — Mon, 18 Sep 2017 00:00:00 +0000

In this paper, the design of a digital thermometer with clock is presented. The design was achieved using ATMEGA 328P PU Microcontroller Unit, MLX90614 Infrared Sensor for achieving contactless measurement (wireless) and the DS1307 Real Time Clock (RTC) for accurate time keeping during the measurement of this parameter.The MLX90614 is factory calibrated in wide temperature ranges from - 40 ºC to 125ºC for the ambient temperature and -70 ºC to 382.19ºC for object temperature, while the DS1307 is a low-power clock/calendar with 56 bytes of battery-backed serial random access memory (SRAM). Power is supplied using a regulated 9 V DC battery. The microcontrollers and RTC chip are powered by 5 V DC. The temperature sensor and liquid crystal display (LCD) require 3.3 V DC for operation and are supplied by passing the 5 V DC through a variable resistor. The sensors output values are both fed into the microcontroller. While monitoring temperature and telling time, the microcontroller sends the measurements in form of digital signal to the LCDs for display.This design was compared with a standard infrared thermometer by taking the body temperature measurements of two individuals at different times of the day. It was observed from the results that the difference between the temperature readings of the two thermometers ranges from 0 to 1 °C

Keywords: Infrared sensor, digital thermometer, microcontroller, real time clock, temperature

Collapsed buildings in Nigeria

I.D. Obot, A.E. Archibong — Mon, 18 Sep 2017 00:00:00 +0000

The purpose of this compendium is to survey why many buildings in Nigeria collapse, during or after completion, and find remedy against future occurrences. The method used here is the stock-taking of occurrences as reported in media. It also takes into account the field – book reports by the authors as they ventured out in the field to interview some architects. It was discovered that quite a number of these cases are never reported for fear of sanctions. The findings were that governments don’t make such sanctions public. Moreover, the use of quacks in the building industry had contributed in no small measure. Conclusion therefore was that, Government must develop stiffer measures on defaulters and get consultants and contractors registered. All registered consultants (architects and engineers) must be made public and Quacks must be made to find their ways out of the building industry. Draughtsmen should not claim to be architects, engineers or builders.

Comparative analysis of the properties of concrete produced with Portland Limestone Cement (PLC) grade 32.5n and 42.5r for use in rigid pavement work

M Joel, I.D. Mbapuun — Mon, 18 Sep 2017 00:00:00 +0000

The properties of different grades of concrete produced with Portland limestone Cement (PLC) grades 32.5N and 42.5R was compared in the study. Initial and Final setting time tests were perform on cement paste. Slump and compacting factor test were performed on fresh concrete. Mix ratios of 1:2:4 and 1:3:6 (Cement: Sand: Granite) by volume and mix proportions for Grades 30 and 40 concrete used in different aspect of rigid pavements, were used to cast concrete cubes and beams that were subjected to compression and flexural strength test after curing for 7, 14, 28 and 56 days respectively. Compressive and flexural strength values of concrete produced with PLC grade 42.5R were higher than values obtained with grade 32.5. The 28 day compressive strength values of concrete produced with PLC grade 42.5R were, 28.0, 30.0, 35.0, and 40.0 N/mm,² while values of 22.0, 28.0, 33.0 and 35.0 were obtained with PLC grade 32.5, for mix ratios of 1:3:6, 1:2:4 and Grade 30 and 40 concrete respectively. Similar trend was observed with flexural strength values. Based on result of test PLC grade 42.5R is an improvement over grade 32.5 and its usage in rigid pavement construction work is recommended as it ensures higher strength and economy in concrete work.

Keywords: Cement, Concrete, compressive strength, Flexural strength

Mathematical model for scheduling irrigation for swamp rice in Port Harcourt L.G.A, Nigeria

U.J. Chiwetalu, M.J. Ayotamuno, E.A. Obio — Mon, 18 Sep 2017 00:00:00 +0000

The thirst for increased food production and management of our natural resources (water) is increasing on daily basis and there is a great need for proper utilization of such important resource. Nigerian farmers today still rely on rainfall for cultivation of food crops, this is simply because they do not have the knowledge of irrigation scheduling and timing and it has affected the rate at which food crops are produced in our country. The formula of a mathematical model that can predict the required amount of irrigation water for swamp rice in Port Harcourt L.G.A. of Nigeria was the main objective of this work. Thus, the formula or the model is given as; d₂ = d₁ + E_RF + I + I_p– ET_c. The maximum and minimum values of water depth (d_max and d_min) required in the field were determined to be 320.32mm and160mm respectively. The result showed that, the model was able to augment the water need of the planted crop except in weeks 5 and 6 which have the values of d₂ (final water depth in the field) as 135.69mm and 120.07mm respectively. While the mother model indicated that the planted crops will be under severe water stress because the values of their d₂ were below the allowable range of water depletion except in weeks 1,7,10,16 and 17 with their d₂ values to be; 178.50mm, 181.47mm, 162.11mm, 198.80mm and 187.60mm respectively. Water application is made on the field whenever the water level is at or below d_min. The result of the correlation analysis for the two models was obtained to be 0.002796. This showed that the two models have a strong non linear relationship between them.

Keywords: Mathematical model, irrigation, Water, swamp rice

Effect of lime pre-treatment mellowing duration on some geotechnical properties of shale treated with cement

M Joel, V.O. Otse — Mon, 18 Sep 2017 00:00:00 +0000

The effect of lime pre-treatment duration on some geotechnical properties of shale treated with cement for use as flexible pavement material was studied. Atterberg’s limits, compaction, California bearing ratio (CBR) and unconfined compressive strength (UCS) tests were conducted on the natural shale and shale pre-treated with 0, 3, 6, and 9 % lime and allowed to mellow for 0, 24, and 48 hours, before it was treated with 0, 3, 6 and 9 % cement. Results of tests shows that lime pre treatment mellowing duration greatly enhance the suitability of shale treated with cement. 7 day UCS value of shale increased from 400kN/m² to peak value of 2311kN/m² when shale pre-treated with 9% lime was allowed to mellow for 48 hours before treatment with 9 % cement. CBR value of natural shale increased from 2.4 % to 112 % when shale pre-treated with 9 % lime and allowed to mellow for 48 hours was treated with 9 % cement. Shale pre-treated with 9 % lime and allowed to mellow for 48 hours before treatment with 6 % cement is recommended for use as road base material in lightly trafficked road and sub-base material of a heavily trafficked road.

Keywords: Cement, Lime, Mellow, Pre-treatment, shale

Software for natural gas pipeline design and simulation (gaspisim)

A.A. Adamu — Mon, 18 Sep 2017 00:00:00 +0000

There is a sudden increase in demand and utilization of natural gas in Nigeria; this may be attributed to federal government policy on establishment of independent power plants and the rising cost of kerosene and fire wood. This increase in demand for natural gas call for design and construction of pipelines for natural gas transportation from production zones to consuming areas. Natural gas transmission through pipelines is accepted as the best method for high capacities gas transmission. Due to the high capital investment and operating cost required for natural gas pipeline transmission systems, optimum designs become inevitable. Cost of compression form a significant part of the operating cost of natural gas pipeline system and can be reduced by optimum design. This paper focuses on the development of software for optimum design and simulation of natural gas pipeline. General Gas equation coupled with correlations for friction factor, Reynolds number, viscosity of gas mixture, compressibility factor etc were used to developed an algorithm from which the software was developed using VISUAL BASIC 6.0. The effect of different operating variables and pipeline dimensions could be investigated using this software. The software was tested for functionality using a typical design problem from literature. Comparison of the software result and that of literature shows that the software can be use for preliminary design and simulation purposes.

Keywords: Pipeline, design, simulation, Natural gas

Teaching and learning methodologies in engineering education in Nigerian universities

Ogri J. Ushie, Julie C. Ogbulezie — Mon, 18 Sep 2017 00:00:00 +0000

The students’ outcome in terms of quality of graduates as regard teaching and learning determines whether the existing methods should be reviewed or not. In the recent world ranking of Universities, only University of Ibadan came among the first hundred despite the number of Universities in Nigeria. This calls for general repositioning of the education sector in Nigeria. This paper examines the teaching and learning of engineering in Nigerian Universities and suggests ways of improving engineering education in Nigerian Universities.

Keywords: Engineering Education, students’ outcome, Tertiary Education and Learning and Teaching methodology