Asian Journal of Engineering, Sciences & Technology
Abbreviated key title: AJEST
Published by: Iqra University
Months: March & September
Start year: 2011
Title: An Evaluation of Some Ionospheric Error Mitigation Approaches Used In Single Frequency Precise Point Positioning (SFPPP) In the Low Equatorial Africa Region Author(s): O.A. Isioye
Abstract: Single frequency GNSS receivers are the most widely used tools for tracking, navigation and georeferencing around the world. It is estimated that over 75% of all GNSS receivers used globally are single frequency receivers and users experience positioning error due to the ionosphere. To enable GNSS Single Frequency Precise Point Positioning (SFPPP), accurate a-priory information about the ionosphere is needed. The variation of the ionosphere is larger around the magnetic equator and therefore depends on latitude, it will be expected that SFPPP works better on latitude further from the magnetic equator. This present study aims to investigate the accuracy of some ionospheric error mitigation approaches used in single frequency precise point positioning (SFPPP) at several GNSS station in the new Nigerian GNSS Network (NIGNet) and two IGS sites in the low equatorial African region. This study covers two epochs of observation, the first consists of observation from three consecutive days (GPS week 1638; days 0,1and 2) that belongs to a period of low solar activities. The second epoch consists of observation from three consecutive days (GPS week 1647; days 2,3and 4) that belongs to a high solar activity and intense geomagnetic conditions. The estimated position for the GNSS stations from dual frequency measurement and their known ITRF solutions were used as benchmark to assess the accuracy of SFPPP under four conditions i.e., SFPPP without ionospheric correction, SFPPP using final GIM models from the Centre for Orbit Determination in Europe( CODE) , SFPPP with Klobuchar model, and SFPPP with a computed (local) model at each station. All computation was done using Leica Geo-office software. The result of the study clearly demonstrates the significance of removing or correcting for the effect of the ionosphere, which can result in up 7m displacement, it was recommended that GIMs from different organization be investigated and also efforts should be towards improvement in algorithms and clock error modeling.
Title: Numerical Simulation of the Decay of Grid-generated Turbulence in a Shock tube Author(s): Mohammad Ali Jinnah
Abstract: The decay of the grid-generated turbulence has been investigated numerically by solving the time-dependent threedimensional Navier-Stokes equations with k-? turbulence model for a compressible fluid. Turbulence grids are placed in the shock tube to generate shock induced turbulence in the wake of the grid plate. All turbulent fluctuations are computed along the longitudinal distance in the wake of the grid plate in the shock tube and it is observed that the decay of the turbulence and the decay of Turbulence Kinetic Energy (TKE) level are accelerated along the downstream direction and the percentage of decay depends on the strength of incident shock wave. Due to stronger compressibility effects on decaying turbulent field, all length scales are decreased along the downstream direction. The decay of dissipation rate of TKE is observed along the downstream direction for gradually decreasing the turbulence intensity in the wake of the grid plate.
Title: Production of Light Weight Concrete by Bio-materials Author(s): H.M.A.Mahzuz, Mushtaq Ahmed
Abstract: The study compares the use of bio-aggregates from rattan, wood and bamboo as coarse aggregate in concrete. Also reinforced concrete short columns were made where the above mentioned coarse aggregates were used having bamboo and rattan as reinforcement. Full study was conducted by OPC, ASTM Type-1, sand of a constant fineness modulus (FM) of 2.79 and water–cement ratio of 0.485. Curing of samples was done for 28 days and crushing was performed after 56 days. The highest and lowest compressive stress was found in the concrete where coarse aggregate was rattan and bamboo respectively. The compressive strength of the specimens was seen to be increased as the amounts of bamboo and rattan as the reinforcement were increased. Moreover, as the weights of the concrete of bio-aggregates were found much less than that of normal weight concrete, therefore as light weight concrete these materials may reduce dead load of structure considerably.
Title: Capacity of Gaussian Relay Channel Author(s): Zahoor Ahmed
Abstract: In commercial wireless communication system, most radios operate in time division duplex (TDD) mode that cannot transmit and receive at the same time in the same frequency band. We present a type of Gaussian degraded relay channel with nodes using light radios.The achievability of Gaussian degraded light relay channel is proved by using superposition encoding and successive decoding techniques. The converse is derived using the min-cut max-flow theorem for networks with light nodes. Our work of capacity analysis shows that even with light radios, our technique of coding is beneficial and has the advantage of capacity over direct transmission.
Title: Space Based Observation Systems for Enhanced Climate Change Mitigation and Adaptation Policies in Nigeria Author(s): O.A. Isioye
Abstract: Climate monitoring, prediction and research have become a core pillar of the global response to climate change mitigation and adaptation. Improved accuracy about the pace of change and better definition of uncertainty levels improves policy definition and may accelerate a global consensus. The United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO), along other international organizations, sponsor the Global Climate Observation System (GCOS). GCOS supports the United Nations Framework Convention on Climate Change (UNFCCC). Operationally, the GCOS has identified 44 Essential Climate Variables (ECV) as being essential to understanding the climate change process and developing the appropriate mitigation and adaptation policies. They are needed to determine the prevailing climate of any given region and to measure rates of change of variables, such as temperature and rainfall (monitoring), to assess the future state of the climate system, years and decades ahead (prediction), supported by continued developments in the collection, archiving, analysis and application of climate data (research). A considerable number of the identified ECVs can be obtained through or at least with significant input from space-based observations. All space-based observations, including ECVs, can be and are already used for a multiplicity of policy applications across policy areas such as climate change, biodiversity, disaster response or monitoring etc. This paper reviews the status of earth observing satellites within the framework of the GCOS, the basic requirements for generating ECVs are identified. Finally the status of space based data for climate change mitigation and adaptation in Nigeria is appraised and suggestions are put forward for an optimal utilisation of space based data within GCOS specification in the country; particularly with the launching of the Nigerian earth observing satellite (Nigeria Sat-2) and the ample number of GNSS-CORS in the country.
Title: Municipal Waste in Nigeria Generation, Characteristics and Energy Potential of Solid Author(s): ItyonaAmber, Daniel M. Kulla, Nicholas Gukop
Abstract: The generation, characteristics and energy potential of municipal solid waste for power generation in Nigeria is presented in this paper. Nigeria generates 0.44-0.66 kg/capita/day of MSW resulting in a waste density of 200-400 kg/m3characterised by organic and inorganic sources.The direct burning of this wastes as a waste management option in the open air at elevated temperatures liberates heat energy, inert gases and ash which can be conveniently used for power generation where the net energy yield depends upon the density and composition of the waste; relative percentage of moisture and inert materials, size and shape of the constituents and design of the combustion system. MSW samples used in this study was obtained randomly from different dump sites in selected state capitals based on the spot sampling method of Corbit.An average calorific value of 17.23 MJ/kg with variable high water content was determined for MSW using a bomb calorimeter and on the basis of an incineration plant of capacity 1500 ton of MSW/day, 700kW/day of power can be generated
Title: A Low Cost Generator Auto Transfer Switch (ATS) Controller for 2-3 KVA Household Generators Author(s): Abdul Atisam Farooq, Abdul Afram
Abstract: Due to the power crisis in Pakistan there is a growing market of small household generators ranging from 2-3 KVA which can handle the load of a small house comprising of a few fans, lights, a computer and a TV. These generators are cheap and come equipped with a self-start mechanism built into the generator. On the push of a button, the user can start the generator easily. In the cities, normally these generators are used for a short period of time when the power from the grid is not available. When the power from the grid is not available the user starts the generator and connects the load to the generator manually. When the power from the grid becomes available, the user disconnects the generator from the load, turns off the generator and connects the load to the grid manually. Normally this function is performed manually and requires the engagement of the user for turning the generator on and off and shifting the load between the generator and the grid. In this paper we propose a controller which performs these tasks automatically. The controller monitors the grid voltage and when there is no voltage, the controller disconnects the load from the grid, starts the generator and shifts the load to the generator. The controller keeps on monitoring the grid voltage and when it comes back on the system turns off the generator and transfers the load to the grid. This system is very useful in the high rate of power failure crisis occurring in Pakistan and relieves the user from the tedious task of attending to the generator regularly for continuous availability of power. There are some commercially available systems in the market which cost even more than the price of a household generator and hence are not economical for the users of household generators. In this paper we propose a very low cost system which can be built using the commonly available components such as relays, timers, transformers, diodes and capacitors. This controller does not require any programmable components such as microcontroller, FPGA, DSP etc. to perform its function. The number of components is kept to minimum to increase the reliability of the system.
Title: Security Risk Analysis in Peer 2 Peer System; An Approach towards Surmounting Security Challenges Author(s): Mansoor Ebrahim, Shujaat Khan, Umer Bin Khalid
Abstract: P2P networking has become a promising technology and has achieved popularity as a mechanism for users to share files without the need for centralized servers. The rapid growth of P2P networks beginning with Kaza, Lime wire, Napsters, Edonkey, Gnutella etc makes them an attractive target to the creators of viruses and other security threats. This paper describes the major security issues on P2P networks (Viruses and worms) and presents the study of propagation mechanisms. In particular, the paper explores different P2P viruses and worms, their propagation methodology, outlines the challenges, and evaluates how P2P worms affect the network. The experimental results obtained will provide new direction in surmounting the security concerns in P2P Networks
Title: Vehicle Intrusion And Theft Control System Using GSM and GPS; An advance and viable approach Author(s): Ashad Mustafa, Hassan Jameel, Mohtashim Baqar, Rameez Ahmed Khan, Zeeshan M Yaqoob, Zeeshan Rahim & Safdar Khan
Abstract: This paper presents a novel approach towards the designing and development of a feasible and an embedded vehicle intrusion and theft control system using GSM (Global System for Mobile Communication) and GPS (Global Positioning System). The proposed system uses GSM technology as one of the distinguishing building blocks of the system. A GPS module Holux GR89 is used to trace the position of the vehicle and Mercury Switches are used to collect analog data continuously, in case of an intrusion, variations will be observed in sensors reading. Continuous readings from sensors are collected on to the microcontroller constantly and on the basis of those readings decision is taken whether an intrusion is made or not and in case of an intrusion a message from a predefined set of messages is generated to the owner of the vehicle and on reception of the message, the owner will have the luxury to take an action via an SMS either to lock the gears of the vehicle or seize the engine of the vehicle from a far-off place. A relay is used to control gears and engine of the vehicle while working with the microcontroller. A prototype system was built and tested. The results were very positive and encouraging.
Title: Building Management System for IQRA University Author(s): Waqar Tariq, Abid Mustafa, Zahid Rasool, S.M.Haseeb, S.Mubarak Ali, Ashad Mustafa†, Shujat Khan, Saad Irfan Warsi
Abstract: In the world of today, a major change in technology can be seen as an advantage, a number of different fields from industrial & communication to household application can be automatically controlled. This paper presents a building management system (BMS) that has been designed for Iqra University using AT89C52, which is the key module in order to perform the controlling and automation. The main area of this BMS focuses on switching and controlling of the power input/output, beside this security and HVAC process has also kept as a main concern in this system.
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