RELIABILITY IMPROVEMENT IN DOMESTIC USE REFRIGERATION: THE

NIGERIAN STOCK

Boniface Onyemaechi Anyaka

Department of Electrical Engineering

University of Nigeria, Nsukka

E-mail: Boniface.anyaka@unn.edu.ng

ABSTRACT

Most domestic refrigeration used in Nigeria contains significant quantities of ozone layer depleting CFCs such as RI1 and R12. This has led to the increasing evaporation temperature and low refrigeration cycle coefficient of performance. This paper takes a look on how performance of house use refrigerators can be enhanced using new compound of C₂HF₂CL₂ and C₂H₂F₄.

Keywords: Compressor, Evaporator, Refrigerant, Refrigerator, Temperature

AN OPTIMISATION TECHNIQUE FOR REAL AND REACTIVE POWER ALLOCATION

Anyaka Bonniface O. and Onyegbadue Ikenna   Augustine

University of Nigeria                                                                                                                      

 E-mail: bonifacedranyaka@unn.edu.ng                                                                                                                      augkey2002@yahoo.com

ABSTRACT

This paper presents a Particle Swarm Optimization (PSO) Technique for Real and Reactive power allocation. In order to optimize the power allocation for a system (power system), a non-linear optimization problem is formulated. The proposed method utilizes the fuel cost coefficient of the generators, transmission losses upper limit and lower limit of the various generating units to optimize power allocation. A Power system with three generating units is considered. Assumed load demands of 200MW is used to compute the power allocation of the 3 generating units as well as the optimized operational cost. The optimized power allocations for the three generating units are obtained by MATLAB scripts on a Matlab 7.5 running on a windows vista operating system. 

Keywords: Particle Swarm Optimization (PSO), Global Best (gbest), Personal Best (pbest), Unit Commitment (UC).   

DESIGN AND EVALUATION OF A HORIZONTAL-SHAFT PALM NUT CRACKING MACHINE

Ologunagba, Francis O.

Department of Agricultural Engineering Technology

Rufus Giwa Polytechnic, Owo, Ondo State. Nigeria

Email:francolog2@yahoo.com

ABSTRACT

A horizontal-shaft palm nut cracking machine was designed, constructed and evaluated.  The basic features of the machine are hopper, cracking chamber, horizontal shaft with beaters, discharge outlet and the prime mover.  The machine was evaluated at three different moisture content of palm nuts (9.81, 11.50 and 13.01% db) and four levels of machine speed (1200, 1480, 1850 and 2220 rpm) at an average feed rate of 450kg/hr.  Test result showed that the machine gave its best work performance at 1480 rpm machine speed and with palm nuts of 9.81% (db) moisture content.  The throughput capacity, percentage kernel breakage and cracking efficiency were 426kg/hr, 4.76% and 75.11% respectively.  The cost of producing a unit of the palm nut cracking machine as at the time of fabrication was estimated to be fourteen thousand, nine hundred and fifty naira (N14,950) excluding the cost of the electric motor, and the power required for operating the machine is 2.25kw.

Keywords:  Palm nut, cracking, moisture content, speed, efficiency.                

ASSESSMENT OF FACTORS THAT AFFECT COST CONTROL BY NIGERIAN CONSTRUCTION CONTRACTORS

Nasiru Zakari Muhammad¹, Kunya, Sani Usman², and Abdurrahman Mutawakkil³

Department of civil Engineering Kano University of Science and Technology, Wudil  Department of Building, Abubakar Tafawa balewa university, Bauchi

Department of Civil Engineering, Kano University of Science and Technology, Wudil                                                                                 nasirumahad@yahoo.com/snkunya@gmail.conm/abmm200@yahoo.com

ABSTRACT

Cost control is an important issue in construction project management. It is widely practiced by contractors in Nigeria and need to carry out through the life of contraction projects. This paper investigates in to the cost control in construction of building and civil engineering projects in Nigeria. Factors affecting the cost of construction in carrying out the project were identified and assessed. Problems faced by contractors in controlling costs were also assessed accordingly .Questionnaires were administered to construction contractors to elicit information with regard to current practice of cost control. Consequently, the data were analyzed using software spss to determine the mean score for each factor which was subsequently ranked accordingly. The student t-test was also used to determine whether there is an agreement in the opinion among the principal participants with regard to factors of cost control. The result shows that the main factors responsible for increasing  cost of project are wrong method of estimation with mean score (8.60) ranked highest followed by incorrect planning with  mean score (8.20) ranked second, high cost of transportation with the mean score (8.0) ranked fourth and fluctuation of price of material with mean score (7.60) ranked third. Spearman ranking was also calculated to determine the level of agreement between the principal participants. The results of the hypotheses show that there is agreement between contractors’ and clients’ opinion with respect to the factors that affect cost control. It also show that there is no agreement in such opinion between Consultants/Clients and Contractors/Consultants.

Significance: This paper shows some light as to the differences in opinions, and the most agreed factors that affect cost control during projects executions as indicated by the clients, consultants and contractors in the industry.

Key words: Assessment, Cost, Control, Contraction industry

DESIGN AND MODELLING OF STRATEGIC INFORMATION SYSTEM

¹Okpeki U. Kazeem and ²Adebari F. Adebayo

¹Department of Electrical/Electronics/Computer Engineering, Delta State University,

²Department of Computer Engineering, Yaba College of Technology, Yaba Lagos.

email:omakazeem@yahoo.com

ABSTRACT

In this paper the design, modelling and management of information system is presented. It takes into consideration the basic component that makes an effective management information system. Many of information system use in many organizations today are very large, inefficient, expensive to maintain and to a very large extent do not meet the real needs of the organization. New applications have been added and new technology deployed without thought given to the system functionality, performance, reliability and security. With this strategy today’s systems will benefits from the advancement made in system engineering and complexity management. 

Keyword: Entrepreneurial activity, data gathering, data processing, pooling, sharing.

AN EXAMINATION OF SOME WOOD PROPERTIES USED IN JEWELRIES

Wuritka, Enoch Gotring

Industrial Design Programme

Abubakar Tafawa Balewa University, Bauchi

email- wuritka.enoch@yahoo.co.uk

ABSTRACT
In order to improve the quality of jewelries there is need to know some properties of woods used as jewelries either synthetic or locally, this study intend to find out the properties of woods used as jewelries, three (3) wood samples were selected base on their physical, mechanical, and chemical properties found. Two (2) different test were conducted which are permeability test compression test, and visuals. The three samples were found to be of good properties in making jewelries. The rate of absorption water is slow and has the ability to withstand attack by organism. It vas observed that the wood samples were durable in terms of strength, the physical properties of the wood samples were found based on their nature, aromatic smell and grain pattern. The wood samples were found to have absorption rate of 33wc%. 47wt% and 56wt%.

GEOMECHANICAL PROPERTIES AND ECONOMIC POTENTIALS OF DOLERITE ROCKS FROM S.E. NIGERIA

Oden Michael I¹., Igonor,Emmanuel E² and Essien, Nse U¹.

¹Department of Geology, University of Calabar,Cross River

²Petra Prospectors Limited,(Nigeria)

ABSTRACT

As developing nations strive to catch up with the rest of the world, good quality construction stones, if found locally and harnessed would help save cost and also ensure the development of local industries. The study area, Cross River State (SE Nigeria), which is within longitudes 8⁰ 00̍ E to 9⁰ 12̍ E and the parallels 5⁰ 35̍ N to 6⁰ 40̍ N, is rich in diverse kinds of igneous and metamorphic rocks, of which some are already being quarried for commercial purposes. A total of thirty (30) dolerite samples were collected from fourteen (14) different localities within the three major geological terrains in Cross River State (Oban Massif, Ikom-Mamfe embayment and Obudu Plateau) and analyzed for their geomechanical properties. Results of sample analysis from these study areas show that density ranges between 2.73 g/cm³ and 2.89g/cm³; Porosity ranges between 1.09% and 1.29%; water absorption capacity is between 0.29% and 0.76%; average specific gravity ranges from 2.79 to 2.93; durability index range from 97.66% – 98.31%; Schmidt Hammer strength ranges from 42.88 N/mm² to 48.93 N/mm²;and uniaxial compressive strength varies from 47.55N/mm² to 51N/mm². Even though the geochemistry of dolerites in general maybe a major setback for their use, all the dolerite samples from the study area, show acceptable physical and mechanical properties, which make them very suitable for the construction/dimension stone industry.

EVALUATION OF THE POTENTIAL OF EVAPORATIVE COOLING FOR HUMAN THERMAL COMFORT A CASE OF KANO, NIGERIA

Ibrahim, U.H¹., A.A. Baba¹ and Ishaq, M².

¹Department of Mechanical Engineering, Federal Polytechnic Mubi, Adamawa State, Nigeria

²Department of Mechanical Engineering, Bayero University Kano, Nigeria

E-mail: heldabuk@yahoo.com

ABSTRACT

In some developing countries like Nigeria, poverty and epileptic power supply are the twin problems impeding people from the use of refrigerated-based air conditioning systems to achieve thermal comfort. Also, the use of some refrigerants has adverse effect on the environment. Evaporative cooling systems are viable options for achieving thermal comfort especially in hot and dry climates. These systems, apart from their low cost and power requirement, they are environmentally friendly. This work attempts to determine the viability of using evaporative coolers to achieve thermal comfort in Kano using the feasibility Index Method. The computed feasibility indices of Kano in the months of January through December are -0.2, 0.1, 0.1, 6.6, 9.5, 14.2, 18, 19.1, 18.2, 10.6, 5.5 and 2.1 respectively. Employing the concept of feasibility index (FI) method reveals that comfort cooling can be achieved in the months of January, February, March, April, May, November and December while relief cooling can be achieved in the months of June and October. The method also reveals the unsuitability of evaporative cooling in the months of July, August and September. Considering both the comfort and the relief cooling periods based on the FI method, evaporative coolers can therefore be used to achieve human thermal comfort in the study area.

Keywords: Feasibility index, Evaporative cooler, Thermal comfort, Temperature

APPLICATION OF NEURAL NETWORK TECHNIQUE TO TELECOMMUNICATION FAULT DOCKET SYSTEM

¹Okpeki U.K and ²Adebari F.A

¹Department of Electrical/Electronics/Computer Engineering, Delta State University, Oleh

 ²Department of Computer Engineering, Yaba College of Technology, Yaba Lagos

email: omakazeem@yahoo.com

ABSTRACT

This paper concerns the application of neural network technique to automatic telecommunication fault docket system. Neural networks have a unique set of characteristics. They are not programmed; instead they are trained by being repeatedly shown large numbers of examples for the problem under consideration. As a result of this, they can provide good results in relatively short timescales but for only certain types of problem, and then a great deal of care is taken over the collection of the data, pre-processing of the data and the design of the network. In this research the feed-forward neural network strategy was adopted with mapping innovation called Kohonen self organizing mapping. It was implemented using Microsoft visual basic 6.0 as front end and Microsoft access 2000 as the back end. The results shows that, by observing great care in data collection, processing and network design, faults are diagnosed and solutions automatically proffered within a short time. This approach results in significant cost saving by improving the availability and efficiency of telecommunication systems.

Keywords: service records, customer service database, intelligent fault docket system, neural process & data mining. 

TRAINING OF CONTRACTORS CRAFTSMEN FOR PRODUCTIVITY IMPROVEMENT IN THE NIGERIAN CONSTRUCTION INDUSTRY

¹Usman, N.D.; ²Inuwa, I.I.; ²Iro, A.I. and ³Dantong, J.S.

¹Department of Civil Engineering, Federal Polytechnic, Bauchi, Nigeria

²Quantity Survey Programme, Abubakar Tafawa- Balewa University, Bauchi, Nigeria

³Deparment of Building, University of Jos, Nigeria

ABSTRACT

Most construction projects in Nigeria fail due to poor contractors’ performance. Firms are concentrating on financial gains and forgetting the people that make the job and money. The problem of the industry is how to reconcile the need for a supply of manpower capable of high productivity in carrying out simplified sequential operations and retains a substantial number of craftsmen capable of highly skilled work. The study aimed at investigating the level and the hindrances to training, and to identify the best training types/methods that will optimize the productivity of construction craftsmen in the Nigerian Construction Industry. The study uses descriptive survey method; two sets of questionnaires were randomly distributed in four north-central states of Nigeria and Abuja to construction professionals and craftsmen. Percentages, severity and importance index were used for the analysis. The chi-square statistics used at 5% level of significance to test the research proposition formulated for the study shows an agreement within the respondent. The study revealed that: level of training among the four trades is very low, with an average training level of 37.21% and an average untrained level among the trades being very high at 62.79%. The older age groups had more training experience than the younger groups. Lack of standard type/method of training adopted for the Nigerian construction craftsmen and lack of encouragement and support for construction craftsmen are the most severe hindrances to training. Vestibule Schools and time release training are the most efficient types/method of training. The study recommend that construction craftsmen should be encouraged and supported for training and as well, vestibule schools and time release training methods should be adopted for training craftsmen in the Nigerian construction industry.

 Keywords: Contractors’ craftsmen; training; productivity; Nigerian construction industry.