Open Access Original Research Article

Design, Fabrication and Performance Evaluation of Indigenous Fish Feed Pelletizing Machine for Low Income Farmers in Nigeria

O. S. Orimaye, P. O. Ajewole, I. O. Oni

Journal of Engineering Research and Reports, Page 1-31
DOI: 10.9734/jerr/2019/v4i316901

The design, fabrication and performance evaluation of a fish feed pelletizing machine for low income farmers was carried out with the view to encourage local technology, as most of the fish feed pelletizing machines available are imported. The fish feed pelletizer is powered by an electric motor and it works by the rotation of a screw auger which propels the feed mix through a die. The screw auger is enclosed in the auger casing and is propelled by an electric motor with the aid of belt and pulleys. This auger is fed through a hopper, which is able to hold a large quantity of the feed mix at a time. The machine was tested using different die diameters of 2 mm, 4 mm and 6 mm. The test was conducted at different moisture content of 10%, 15%, 20%, 25%, 30% and 35% wet basis. The machine test results showed that the pelletizing efficiency increases as moisture content and die diameter increase. The machine throughput also increases with both moisture content and die diameter. Highest efficiency of 98% was obtained when the moisture content was maintained at 25% wet basis and the feed materials were made to pass through 6 mm die diameter. The total cost of the design and construction of this pelletizing machine was one    hundred and five thousand naira (N105, 000.00) which is still reasonably affordable by small scale famers.

Open Access Original Research Article

Design and Implementation of an Electric Cooker Control System as a Means of Preventing Domestic Fire Incidence

O. O. Akinwole

Journal of Engineering Research and Reports, Page 1-9
DOI: 10.9734/jerr/2019/v4i316902

Open loop control system is the type without feedback, that is, no sensor sensing the control variable, hence works on time basis. The paper established the facts that the system will prevent ubiquitous fire incidences associated with electric stoves and other heating devices. It describes the application of simple electronics circuitries in designing the low cost Cooker Control Device. The building blocks of the unit were designed one after the other using preferred components available in the local markets. The project was wired on Breadboard. The board permits the design to be tested without employing soldering processes. The design enumerates some important construction precautions which are further accentuated with the inclusion of various tips on healthy soldering processes. It is believed that the unit will prevent fire incidences associated with electric cooker. Simple explanations given to drive home power electronics principles used and copious illustrations rendered will make the innovative and ingenuous enterprise interesting to power electronics enthusiasts and other professionals alike. The paper recommends incorporation of embedded system with Liquid Crystal Display in the future design improvement.

Open Access Original Research Article

Novel Characterizations of the JK Bistables (Flip Flops)

Ali Muhammad Ali Rushdi, Fares Ahmad Muhammad Ghaleb

Journal of Engineering Research and Reports, Page 1-20
DOI: 10.9734/jerr/2019/v4i316903

The JK flip flop is a flexible type of bistable elements that has extensive uses in digital electronics and control circuits. It is usually described by its characteristic equation or next-state table (used for analysis purposes) and its excitation table (used for synthesis purposes). This paper explores a variety of novel characterizations of JK flip flops. First, equational and implicational descriptions are presented, and methods of logic deduction are utilized to produce complete statements of all propositions that are true for a general JK flip flop. Next, methods of Boolean-equation solving are employed to find all possible ways to express the excitations in terms of the present state and next state. The concept of Boolean quotient is used to impose certain requirements so as to find particularly useful expressions of the excitations. Relations of JK flip flops to other types of flip flops are also explored. This paper is expected to provide an immediate pedagogical benefit, and to help facilitate the analysis and synthesis of sequential digital circuits.

Open Access Original Research Article

Sanding and Shaping Characteristics of Gmelina arborea Grown in Two Ecological Zones in Ghana

Stephen J. Mitchual, Francis W. Owusu, Maxidite A. Minkah

Journal of Engineering Research and Reports, Page 1-12
DOI: 10.9734/jerr/2019/v4i316904

Poor machining of wood generates more residues which leads to low recovery in wood processing. Therefore, the availability of appropriate wood machining techniques would promote efficient utilization of logs. This study looked at the shaping and sanding properties of Gmelina arborea - a lesser-known species in Ghana - in order to promote its efficient utilization. Six trees from plantations at the Wet Evergreen and Dry Semi-Deciduous Forest Zones were extracted and processed into lumber using LT 15 horizontal wood-mizer. The average moisture content of samples just before the test was 14.57%. Specimens were prepared in accordance with ASTM D 143-83 and ASTM D 1666-87 (2004) for the sanding and shaping tests. The effects of tree location, grit size and spindle speed on sanding and shaping properties of Gmelina arborea wood were assessed using the visual approach. For the sanding test, grit size P80 was the best sandpaper to remove chipped and torn grain defects from the surfaces of Gmelina arborea lumber after planing. Spindle speed 10,000 rpm gave the best shaping output so it was recommended for shaping Gmelina arborea timber grown in Ghana. For the shaping operation, wood samples obtained from the Dry Semi-Deciduous Forest Zone had better surface quality than those obtained from the Wet Evergreen Forest Zone. A similar trend was obtained for the sanding test. The most common defects observed during grading of the shaped specimens were raised, chipped and fuzzy grains and those observed for the sanded specimen were fuzzy and scratchy defects. At 5% level of significance, tree location and spindle speed had significant effect on the surface quality of the shaped specimen.

Open Access Original Research Article

Design of Common-Source/Drain Active Balun Using 90nm CMOS Technology

Frederick Ray I. Gomez, Maria Theresa G. De Leon, John Richard E. Hizon

Journal of Engineering Research and Reports, Page 1-9
DOI: 10.9734/jerr/2019/v4i316906

This research paper presents a design and study of a common-source/drain active balun circuit implemented in a standard 90-nm complementary metal-oxide semiconductor (CMOS) technology.  The active balun design is intended for worldwide interoperability for microwave access (WiMAX) application, with operating frequency of 5.8GHz and supply voltage of 1V.  Measurements are taken for parameters namely gain difference, phase difference, and noise figure.  The common-source active balun design achieved a minimal gain difference of 0.016dB, phase difference of 180° ± 7.1°, and noise figure of 7.42-9.85dB, which are comparable to past active balun designs and researches.  The design eventually achieved a low power consumption of 2.56mW.