Digital signal compression in the recent past has become the mainstay of the basic technologies of multimedia due to the bandwidth and storage limitations inherent in networks and computers. The change from circuit switched to packet switched systems in the telecommunication infrastructure in the past few years, has reflected on the way Pulse Code Modulation (PCM) signal which in essence is a raw audio signal, is carried in present systems. The purpose of this study was to design an applicati...
LPG is widely used in our everyday life. It should be handled with care as it is highly flammable which causes а fire or explosion. The above circumstances can be overcome by implementing techniques for detecting accurate gas leaks. The main aim of this paper is to put forth an IOT gas management system that will be able to sense gas leakage and fire detection. Whenever leakage of gas is detected, the user will be alerted through SMS and call so that the user can turn off the gas valve immed...
In the recent past the use of renewable energy as an alternative source of energy has increased considerably. The solar cells modules manufacturing technology is becoming more reliable and economical. The feasibility of photovoltaic solar energy as an alternative source of energy has become real. The low efficiency and the weather condition dependency give room for improvement of this technology to extract maximum power for different environmental conditions. Therefore, the current–volt...
Phase Change Random Access Memory (PCM) is one of the most optimized candidates for the next generation non-volatile memory due to its fast operation speed, high scalability, low power operation and fabrication costs. The transition from the amorphous to the crystalline phase is induced by heating the material above its crystallization temperature for a long enough time, and the switching back to the amorphous phase is realized by melting and quenching the material fast enough that it solidif...
ABSTRACT There has been a steady increase in demand for clean and renewable energy globally. As a result, more effort has been put into research to harness solar energy from the sun to generate electricity using solar cells. Solar cells convert solar energy directly into electricity. Recent research findings indicate that properties of thin film solar cells strongly depend on the various deposition techniques chemical bath deposition (CBD) being one of them. This technique yields stable, adh...
ABSTRACT Despite the installation of light energy waste control systems in modern buildings, many people end up paying for high energy bills. The cost of installation of these systems is usually high, and most of them are inefficient making it a major concern to the normal user. Due to technological advancement, sensors and microcontrollers are employed in a wide range of applications. This includes domestic and industrial fields where they aid in control of automated processes. In these app...
ABSTRACT A linearly-polarized aperture coupled microstrip antenna design is characterized and optimized using FEKO antenna simulation software. One of the major drawbacks of these microstrip antennas is their narrow bandwidth. Aperture coupled being one of the feeding technique has proven to be a solution to this problem. In this research a patch antenna that is coupled to a microstrip-line by an aperture in the intervening ground plane has been designed and fabricated and implemented. The sh...
ABSTRACT The CdS and PbS are of great research interest due to their outstanding electronics and optical properties such as winder energy band gap phase and good antireflective properties respectively. CdS has been earlier doped by Zn and used as a window layer combined with PbS as the absorber material using the CBD method. It realised an efficiency of 0.9. It is for this reason in my research, I doped CdS with Se in the fabrication of CdxSe1-xS/PbS PN junction for solar cell application to...
ABSTRACT The rapid population growth in Kenya and the world in general has led to very high energy demands; this has necessitated urgent exploration of other alternative energy sources. Solar energy is one such alternative that has not been fully utilised hence many researchers have developed much interest in them. Solar cells absorb light from the sun and convert it in to useful electrical energy however the challenge has been how to harness it as well as the very low efficiencies recorded b...
ABSTRACT Solar photovoltaic (PV) energy has been widely used for decades especially where connection to a national grid is seldom possible and other sources such as fossil fuel and others are either unavailable or uneconomical. Solar PV energy owing to its free, natural availability and environmental friendliness has found demand for use in industries, homes and institutions. However, very little research has been carried out to precisely establish its effectiveness, reliability and adequacy....
ABSTRACT Communication systems require development of low cost, low profile and minimal weight. Microstrip antennas (MSA) are capable of maintaining high performance over a wide spectrum. Technological trends have focused much effort on the design of the microstrip patch antennas. In this study, square, circular and rectangular patches were designed and analyzed using two different substrates. High Frequency Structure Simulator (HFSS) software was used to simulate, model and analyze the MSAs....
ABSTRACT Microstrip patch antenna(MSA) has become very vital in communication system due to its attractive features such as its light weight, small size, low cost, low profile, ease of installation and its conformability to planar and non planar surfaces, when a particular mode and shape is selected. MSA are versatile in terms of resonant frequency, impedance, polarization and electromagnetic wave pattern. However, MSA have been found to suffer from relatively narrow bandwidths. The consumers...
ABSTRACT Climate uncertainties pose a challenge to the production of food to feed the growing billions on the globe. Climatic conditions can change abruptly ruining farming efforts and leading to food shortages. Greenhouses attempt to solve this problem by enclosing crops in a climatically controlled environment. Crop production in greenhouse environment has the advantage of obtaining reliable and continuous output throughout the year. Each greenhouse has distinct characteristics. Data on the...
ABSTRACT Greenhouse technology should be embraced as a way of minimizing food insecurity in Kenya. The insecurity is brought about by climate uncertainties. Greenhouses have attempted to solve this problem by enclosing crops in a climatically controlled environment. Each greenhouse has distinct parameters. Data on these parameters need to be collected at regular intervals. Depending on the type of crop, these parameters need to be controlled within the specified limits to achieve the maximum...
ABSTRACT Audio noise monitoring and control has been a subject of research for several decades. Researchers have developed audio noise monitoring systems which rely on computers, internet and mobile telephone services which are costly and bulky and whose output is not easy to associate with any medical or psychological effects of noise. Active noise control has been explored using digital signal processors and field programmable gate arrays which are more costly than microcontrollers. Complex...