Babale, S.A., Ahmad K., Musa, M. J., Sha’aban, Y. A..
Page No : 1-5
CELL-PHONE BASED INTRUDER ALARM USING PIC 16F877A MICROCONTROLLER
There are many security systems like Closed Circuit TV (CCTV) cameras which serve as a good asset and can help in fighting against crime. It has limitations, once a criminal observe its presence, he will quickly change tactics. Also CCTV cameras and other security systems can only filmed the intruder but not necessarily make an alert. This research work provides an immediate action once an intruder penetrates into someone’s territory by calling his mobile phone number. This paper presents a system designed to improve the home safety and the conventional alarm system today. The system is not only to detect any intrusion and turn on the bell alarm but also tell the owners by calling their cell-phone. The main focus of this paper is to generate the DTMF (Dual Tone Multi Frequency) tones using a cheap Programmable Integrated Circuit (PIC) Microcontroller and other components of the circuit. The theory of the DTMF tones generation is discussed in quite detail with suitable graphs shown in this paper. This system is already designed and constructed successfully where it generates the DTMF tones and able to make a call to a specific cell-phone number.
Ahmad K., Babale, S.A., Sha’aban, Y. A., Moddibo A. A..
Page No : 6-11
DESIGN AND DEVELOPMENT OF A MICROCONTROLLER BASED COLOR – CODED – RESISTOR READER
This paper presents the design and development of a microcontroller based color - coded - resistor reader. The
device is intended to be used for giving the exact value with the percentage tolerance of a color coded resistor
when the colors on the resistor are entered to the device using a keypad. Microcontroller (PIC) IC 16F887 is
used as the brain of the system. The PIC is programmed using ASSEMBLY programming language. Discrete
and integrated electronic circuit (IC) components are used to design and implement the system. Also an effort
is made to ensure good reliability as well as cost effectiveness for the designed system to be reliable and
affordable to everybody. The device developed was found to be functioning satisfactorily when tested.
Mohammed, U. S., M. L. Suleiman, O. J Mudiare, M. ISIAKA.
Page No : 12-18
EFFECT OF KNIFE WEIGHT ON CUTTING ENERGY AND EFFICIENCY DURING IMPACT CUTTING OF SORGHUM STALK
Sorghum stalk cutting performance in terms of cutting energy requirement and cutting efficiency has
been investigated using a laboratory pendulum-like oscillating impact test rig. The stalk was fixed in a stalk
holder to simulate a free-standing stalk in the field. A blade was attached to the lower end of the oscillating
arm which cut the stalk at 90o cut angle. Knives of various weights ranging from 1.00 to 4.85 kg were tested in
cutting the stalk base at 20 and 120 cm. Cutting energy showed negative linear correlation with knife weight
while cutting efficiency showed positive correlation with the parameter. There was decrease of 2.36 and 9.91
Nm cutting energy requirement and increase of 20.65 and 40.07% cutting efficiency for every 1 kg increase in
knife weight at 20 and 120 cm cutting height respectively, from the ground level. The optimum values of knife
weights were 3.42 and 1.85 kg for cutting at 20 and 120 cm respectively, corresponding to cutting energy of
20.50 and 36.50 Nm and efficiency of 98 and 96 %.
S.B. Ibrahim .
Page No : 19-26
ASSESSMENT OF THE RELIABILITY OF INDUCTION MOTORS INCORPORATED WITH CONDITION MONITORING SYSTEMS IN PETROCHEMICALS PLANT
Continuous operation of induction motors is essential to the function of petrochemicals process plants.
Fortunately, induction motors are inherently quite reliable. They are so reliable that standard practice had
been simply to run the motors until they fail. Periodic visual inspection and lubrication have been the limit of
maintenance practice. As petrochemicals plants have become larger and more integrated, requirements for
reliable motor operation have increased. Many plants have induction motor populations in the thousands. Of
these, several induction motors are vital to the continuous function of the plant. These critical motors have
become the focus of reliability assurance programs. In addition to the necessity for continuous output from the
plant, some induction motors are essential to safety. On-line condition monitoring of induction motor in
critical applications has become increasingly necessary to improve their reliability and to minimize
catastrophic failures. A method for the evaluation of the improvement of induction motor reliability made by
such monitoring systems is presented. Simple probabilistic models are used to estimate the reliability levels,
based on data collected from Indorama Eleme Petrochemicals Limited, Nigeria (IEPL) for a period of five
years (2006-2011). Estimates are given for the reliability improvement of induction motors with monitoring
systems. The results clearly indicate the viability of the comprehensive monitoring systems, in terms of the
improvement in the reliability index. Comprehensive monitoring system is expected to raise the average
annual reliability levels of induction motors operating in petrochemicals industries to over 97.44% for all the
categories of squirrel cage induction motors with ratings in the range of 15 to 375Hp
S.B. Ibrahim .
Page No : 27-34
OPTIMAL THEORETICAL OUTPUT TORQUE OF A STEPPER MOTOR BASED ON POWER DISSIPATION CONSTRAINTS
Stepper motors are extensively used for a wide range of applications, especially for precise position control. This is due to their advantages of having higher efficiency; maintenance of very high resolution due to their variable step angle, their positional error is non-cumulative and is compatible with modern digital equipment. However, a major limitation in the use of stepper motor is that their output torque is lower than that of a comparable dc motor. Therefore, to maximize their output torque, their phase current must be increased. Though, increase in their phase current will result in increased power dissipation in the phase windings of the motor and consequently reduce the efficiency of the motor. This paper considered the problem of maximizing the output torque of a stepper motor while satisfying power dissipation constraints. Also, the optimal current which maximizes the output torque is derived. Several sub-optimal driver control modes are compared to the optimal one and their relative power output evaluated. When the driver mode is a square current wave, there is a 10% loss in motor output power for the same power dissipation. When the motor is driven by a voltage source it was found that the output power of the motor is nearly the same as when driven from current sources when the motor speed is low. However, a noticeable reduction occurs at increased motor speed. It is shown that the most common driver control mode (i.e. using square wave voltages) is the least efficient from the torque versus power dissipation constraint point of view.
A.Y. Abdulfatah, A. Idris, M. Umar.
Page No : 36-40
VARIATION IN PERMEABILITY AND SURFACE AREA WITH CHANGES IN SOIL PARTICLE SIZE
This paper focuses on the extent of variation in permeability and surface area of soils when particle size distribution (psd) of the soils changes. Particle size distribution is the distribution of the weight or volume of solid particles falling into different size ranges. Two different soil samples were collected as sample A and sample B and the distribution of their particle sizes were determined. Ethylene glucol was used as an adsorbate in the determination of the surface area of the soils in the two samples. Falling head and constant head permeability tests were used to determine the permeability of the soil samples respectively. The results obtained in this study have corroborated the theories in soil mechanics that say the more the amount of fines in a soil the larger the surface area and the smaller the permeability of the soil.
Page No : 41-48
THIN-LAYER DRYING CHARACTERISTICS OF SLICED TOMATO UNDER FORCED CONVECTION SOLAR ENERGY DRYING
Thin layer drying characteristics of sliced tomato under forced convection solar drying was investigated.
Using airflow rate and sliced thickness as variables, five model equations were evaluated. Each of the
equations was linearised and then least square technique was used to obtain the models’ parameters. The
results revealed that at 15 and 20 mm sliced thicknesses, Page’s and Modified Page’s model equations
adequately describe the thin layer drying characteristic while at 25 mm sliced thickness only Modified
Page’s model equation gave the best prediction. The best results were obtained at 15mm slice thickness
and 4.50m3/s air flow rate. The results, also, showed that the resistance to moisture diffusion increases
with increase in slice thickness. The Modified Page’s model adequately describes the drying
characteristics of sliced tomato under forced convection solar drying.
AHMAD, H. I, D. AHMAD, D. D YUSUF, M. L. SULEIMAN.
Page No : 49-55
REPAIR AND MAINTENANCE COST PREDICTION MODEL FOR STEYR URSUS TRACTORS USED IN SOLID HOUSEHOLD WASTE (SHW) COLLECTION AND DISPOSAL
A standard model was developed for the prediction of repair and maintenance costs of Steyr Ursus tractors used for solid household waste (SHW) collection and disposal in Kano State of Nigeria. The model was derived based on data collected over a period of eight years from Refuse Management and Sanitation Board (REMASAB), Kano- Nigeria. The model predicts repair and maintenance costs as a function of tractor cumulative use in hours. Among the five models (linear, logarithmic, quadratic, power and exponential) produced through regression analysis, the quadratic model (R2 = 0.81) having the highest coefficient of correlation is adjudged as the best fit for managing the tractors under the operation being used for.
Kuda, A.T., Jibril, M.M., Gin, A.J..
Page No : 56-65
EFFECTS OF FREQUENCY OF VIBRATION ON THE SEGREGATION OF GRANULAR MATERIALS
The effect of frequency on the segregation of large spheres in a granular bed under vertical vibrations is studied. Segregation of granular materials is a problem of great consequence in industries involved with the handling and processing of granular materials in which homogeneity is generally required. In our experiments, we systematically measure rise times of the intruder particle as a function of frequency. The measurements reveal that: at constant acceleration the segregation was found to decrease in the frequency range of 20 - 40 Hz and then increases with increasing frequency. However, with increasing acceleration, the segregation decreases in the frequency range of 20 - 40 Hz and then starts to decrease exponentially with increasing frequency.