Open Access Original Research Article

Experimental Investigation of the Performance and Energy Consumption of an Automated Ice-cube Making Machine

Rasheed Ayofe Shittu, Isaac Femi Titiladunayo

Journal of Engineering Research and Reports, Page 1-12
DOI: 10.9734/jerr/2018/v3i116700

Aims: This study investigates the performance of a developed automated ice-cube making machine under controlled ambient conditions, in which its energy usage, rate of ice cube production and refrigeration system performance was analysed.

Study Design: Average ambient temperatures of 24°C and 32°C were considered for investigation in order to determine their influence on ice production capacity, rate of ice-cube making and energy consumption. The choice of the ambient temperature is based on the extreme ambient conditions under which the machine is designed to operate in a wide range of geographical regions. The refrigeration system performance was carried out under normal room temperature (average of 23°C).

Place and Duration of Study: Department of Mechanical Engineering, Federal University of Technology Akure, Ondo State Central Workshop, Between December 2017 and January 2018.

Methodology: The machine was set into operation for 5 consecutive ice production cycle during which the ice making time, harvest time, quantity of ice produced and energy consumption were recorded.

Results: The ice production capacity, harvesting time and energy consumption show various dissimilarities at both temperatures. 0.618 kg of ice cubes were produced within an ice making cycle of 34.9 minutes, harvesting time of 1.28 minutes and total energy consumption of 0.14053 kWh at 24°C while at 32°C, the machine produced an average of 0.612 kg ice cubes within an ice making cycle of 38.5 minutes harvesting time 1.21 minutes and energy consumption of 0.15947 kWh respectively. Consequently, 13.5% more energy is consumed, with about 1% less quantity of ice produced at 32°C than at 24°C per ice production cycle.

Conclusion: Therefore, the ice making capacity of the developed machine suggests that the temperature of the environment has a strong influence on the energy consumption, but little effect on the quantity of ice produced per cycle. The refrigeration system cycle performance analysis results showed a considerably high cooling capacity of 0.379 kW during the ice-making cycle with a corresponding coefficient of performance (COP) of 2.23, and a heating capacity of 2.24 kW during the harvest cycle with a corresponding COP of 8.21. The results obtained showed that the machine is reliable in operation with minimal energy consumption.

Open Access Original Research Article

An Improved Logistic Function for Mapping Raw Scores of Perceptual Evaluation of Speech Quality (PESQ)

A. Olatubosun, Patrick O. Olabisi

Journal of Engineering Research and Reports, Page 1-10
DOI: 10.9734/jerr/2018/v3i116704

Voice service being the major offering of telecommunication networks, its level of Quality of Service (QoS) largely determines the performance of these networks. This work evaluated the state-of-the-art Perceptual Evaluation of Speech Quality (PESQ) objective model for perceptual estimation of the quality of transmitted speech signals. Perceptual estimation of the quality of speech is predominantly done by subjective techniques and the results presented as Mean Opinion Scores (MOS), which has a scale from 1 for poor quality to 5 for excellent quality. Despite constraints of the subjective approach to perceptual speech quality estimation, its scores serves as the basis for correlating quality scores from objective techniques for speech quality estimation. Original or reference speeches were recorded using professional studio equipment and software, and guided by provisions of ITU-T P.830. The speeches were transmitted over three mobile wireless networks. A speech database consisting of 64 original (32 male and 32 female) and 192 transmitted speeches was developed. Reference speeches and their corresponding transmitted (network-degraded) speeches were tested on the PESQ model to estimate their quality scores. The raw PESQ quality scores are within the scale range of -0.5 and 4.5. They were mapped to the MOS scale for linear comparison of the scales. Study of PESQ model showed several shortcomings, some of which have been improved upon by previous researchers. Evaluating PESQ mapping function (in ITU-T Rec P.862.1) showed the need for better coverage of the MOS scale. Analysis of solution for the logistic growth function was done and parameters were optimised which resulted in the development of a new robust logistic mapping function. The raw PESQ quality scores were mapped using the developed mapping function as well as two known standard mapping functions, namely: ITU-T P.862.1 and Morfitt and Cotanis mapping functions. The mapped scores known as PESQ MOS-listening quality objective (PESQ MOS-LQO) obtained with the three functions were tested using ANOVA at a significant figure of . The developed logistic mapping function offered a quality score coverage of 98.6% of the MOS scale. This was evaluated against the two known standard mapping functions and the developed function offered improvement of 11.8 and 4.9% over and above their 86.8 and 93.7% coverage of the MOS scale respectively. At the significance level of , an F-value of 60.6042, a critical-F of 3.04, and a p-value of 4.61721E-21 were obtained. With p < 0.05, the Null Hypothesis was rejected, and the critical-F value being less than the F-statistic value confirmed the rejection. Therefore, the data distribution of at least one of the functions has a different mean and belongs to a separate population of performance.

Open Access Original Research Article

Formulation of Lubricant from Calabash Seed Oil

F. J. Owuna, M. U. Dabai, M. A. Sokoto, U. Z. Faruq, A. L. Abubakar

Journal of Engineering Research and Reports, Page 1-8
DOI: 10.9734/jerr/2018/v3i116866

The engine oil market is faced with complex chemical reactions and difficult chemical engineering involved in the formulation of synthetic based engine oils, and therefore, the need to source for alternative base oils for engine oil formulation from vegetable oils has become urgent and inevitable. This research is aimed at formulation of lubricant using calabash seed oil (CSO). An experiment designed (Mixture Design Method using Minitab 17) was used to obtain the blend of CSO (28.75%), SN 500 (68.75%), and additive (2.50%) with improved physicochemical parameters. The lubricant obtained had kinematic viscosities 9.30±2.11 cSt (at 100°C) and 53.11±1.03 cSt (at 40°C), a viscosity index of 167±0.51, flash point of 240±2.01°C, and pour point of -28±1.31°C. The lubricant obtained in this research had quality parameters that are comparable to those of synthesised environmentally acceptable engine oils, and are within the standard for engine oils.

Open Access Original Research Article

Line Stressing Critical Processes Optimization of Scalable Package Passive Device for Successful Production Ramp-up

Antonio R. Sumagpang Jr, Frederick Ray I. Gomez

Journal of Engineering Research and Reports, Page 1-13
DOI: 10.9734/jerr/2018/v3i116867

The technical paper presents a systematic and methodological approach to deal with a new product trend that will be successfully manufactured during assembly production ramp-up.  The project is intended to determine the required process flow and machine platforms for high-density and high-complexity scalable device. Critical processes are shown and top reject contributors are addressed through systematic method by using statistical tools and in-depth engineering analysis.

The Scalable Package Passive Device is one of the newest and latest developed device in the plant, which functions as a diode for mobile and computer applications.  The device is considered high density as its 6” single wafer is equivalent to 400,000 units compared to conventional device consisting of only 1,000 units.  Moreover, it is considered as a device with high complexity as state-of-the-art platforms are needed to satisfy its output process.  Furthermore, the device has a very thin die and with the smallest total package dimension.  The process of assembly manufacturing includes a step cutting method of wafers, compression molding, and in-strip testing, which are unlikely to be found on other semiconductor industries. Ultimately, complex errors and top reject contributor of identified critical processes are corrected and the target or required process capability index is effectively achieved.

Open Access Original Research Article

Analysis of the Synthetic Gas Production from Saw Dust Gasification

Akinyemi Oluwaseyi Raphael, Olaiya Niyi Gideon

Journal of Engineering Research and Reports, Page 1-11
DOI: 10.9734/jerr/2018/v3i116868

Aims: Produce combustible gas from sawdust for domestic house use.

Study Design: A fluidized bed gasifier suitable for sawdust gasification was used.

Place and Duration of Study: The study was done at the federal university of technology akure, Ondo state Nigeria

Methodology: Sawdust was first processed by converting it to pellets. Tests were carried out on the pellets using a bomb calorimeter using the ASTM-E771 standard. On experimental, the pellets were loaded into the reactor and then fired. Air was forced into the plenum, after which the air distributor plate evenly distributed jets of air in the bed resulting in complete and incomplete combustion.

Results: Experimental tests showed that the pellets have a heating value of 16.36 MJ of energy per kg and a higher percentage of volatile matter of 57.62% (ASTM-E872) and a lower percentage of fixed carbon than the initial sawdust sample. The produced synthesis gas composed of methane 63.4%, Ammonia 1.09%, Carbon monoxide 0.63%, Hydrogen sulphide 0.84% and carbon dioxide 34.04%.

Conclusion: The gas was ignited showing it was combustible.