146 research outputs found

    NEW MODEL FOR SOLAR RADIATION ESTIMATION FROM MEASURED AIR TEMPERATURE AND RELATIVE HUMIDITY IN NIGERIA

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    Solar radiation prediction is essential for effective and reliable solar power project, predicted solar radiation can be used for accurate solar energy prediction. Solar radiation measurement is not sufficient in Nigeria for various reasons such as maintenance and repair cost, calibration of instrument, and expansive of measuring device. In this paper, adaptive neuro-fuzzy inference system (ANFIS) model was developed to predict the monthly average solar radiation in Nigeria. Air temperature of monthly mean minimum temperature, maximum temperature and relative humidity obtained from Nigerian Meteorological Agency (NIMET) were used as inputs to the ANFIS model and monthly mean global solar radiation was used as out of the model. Statistical evaluation of the model was done based on root mean square error (RMSE) and correlation coefficient R to examine the accuracy of the developed model. The values of RMSE and R for the training data are 0.91315MJ/m2 and 0.91264MJ/m2 respectively. The obtained result showed a good correlation between the predicted and measured solar radiation which proves ANFIS to be a good model for solar radiation prediction.  http://dx.doi.org/10.4314/njt.v36i3.3

    Analysis and Performance Evaluation of Microbial Fuel Cells for Electricity Generation

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    This research work is focused on the analysis and performance evaluation of microbial fuel cells (MFCs) consisting of multiple one chamber connected in series and parallels for investigation of electricity generation. Using six units (i.e., unit A, unit B, unit C, unit D, unit E, unit F, unit G and unit H) stacked MFCs, the fuel cells were analyzed and evaluated for performance. The results obtained with a single unit microbial fuel cells show that, unit (A) produced an average power of 0.224mW, unit (B) an average power of 0.179mW, unit (C) an average power of 0.138mW, unit (D) an average power of 0.092mW, unit (E) an average power of 0.058mW, unit (F) an average power of 0.036mW, unit (G) an average power of 0.018mW, and unit (H) an average power of 0.005mW. It was observed that decrease in number of microbial fuel cells lead to a corresponding decrease in voltage and current generated, thus drop in power. Conversely, when the unit microbial fuel cells were connected together in series and parallel, improvement in power generation was recorded. An average power of 2.681mW and 2.572mW were obtained from series and parallel connection respectively.Keywords: Microbial fuel cells, anode, cathode, power, renewable energy, electricity generatio

    MULTIBAND MILLIMETER WAVE T-SHAPED ANTENNA WITH OPTIMIZED PATCH PARAMETER USING PARTICLE SWARM OPTIMIZATION

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    This paper proposed a simple T-shaped patch antenna for millimeter waveband frequency operation. Millimeter wave is a frequency ranges between 30GHz to 300GHz in an electromagnetic spectrum. The proposed antenna consists of T-shape radiating patch mounted on rectangular substrate (FR4-4) and microstrip line for antenna feeding. An evolutionary algorithm called particle swarm optimization was used to optimize the length and width of the proposed antenna patch. The proposed antenna gives triple bands with central frequencies at 42GHz, 51.5GHz and 60GHz. The antenna offers minimum return loss of -19db, -24db and -19.5db at 42GHz, 51.5GHz and 60GHz respectively. The return loss impedance bandwidth of 5GHz for the first band, 8.4GHz for the second band and 5GHz for the third band was obtained. The proposed antenna was analyzed using Ansoft High Frequency Structure Simulator (HFSS) and MATLAB 2013. Radiation characteristics of this patch antenna are observed at various resonating frequencies.  http://dx.doi.org/10.4314/njt.v36i3.3

    Effects of Fadama III Project on Dry Season Onion Farmers’ Income in Sokoto State, Nigeria

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    The effect of Fadama III project to the improvement in the income of participating dry season onion farmers inSokoto State was studied. Population of the study comprised of all dry season onion farmers in Sokoto State.Purposive sampling was used to select six Local Government Areas, while random sampling technique was usedto select 15 respondents each from the project participants and non-project participants in each of the six LocalGovernment Areas. Descriptive statistics and gross margin analysis were used for data analyses. Findings of thestudy revealed that Majority (63.53% and 76.40%) of project beneficiaries and non-project beneficiariesrespectively did not attain any form of formal education. Cost of fertilizer dominated the production cost for boththe project beneficiaries (46.61%) and non-project beneficiaries (55.99%) of total cost. Result of the gross marginanalysis shows that the project participants made more profit in dry season onion production (₦241, 854.89)compared to the non-project participants (₦63,328.59). It was recommended that Fadama III project should as muchas possible expand their area of operation so that more farmers can benefit from their services

    TimeSets for uncertainty visualisation

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    TimeSets consist of a timeline showing sequence of events displayed across a visualisation, while makings sense of sets relation among events in the timeline [NXWW15]. This study looked into extending TimeSets to accommodate Visualisation of trust and uncertainty as parts of its variables for events displayed across the timeline. The aim of the challenge is to build tools in the context of big data analytics that can be used to aid military operations through intelligence analytics and decision-making

    Determinants of foreign direct investment in fast-growing economies: evidence from the BRICS and MINT countries

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    Abstract The flow of foreign direct investment (FDI) into a country can benefit both the investing entity and host government. This study employed panel analysis to examine the factors that determine the direction of FDI to the fast-growing BRICS (Brazil, Russia, India, China, and South Africa) and MINT (Mexico, Indonesia, Nigeria, and Turkey) countries. First, we used a pooled time-series cross sectional analysis of data from 2001 to 2011 to estimate and model the determinants of FDI for three samples: BRICS only, MINT only, and BRICS and MINT combined. Then, a fixed effects approach was employed to provide the model for BRICS and MINT combined. The results demonstrate that market size, infrastructure availability, and trade openness play the most significant roles in attracting FDI to BRICS and MINT, while the roles of availability of natural resources and institutional quality are insignificant. To sustain and promote FDI inflow, the governments of BRICS and MINT must ensure that their countries remain attractive for investment by offering a level playing field for investors and political stability. BRICS and MINT governments also need to invest more in their human capital to ensure that their economies can absorb substantial skills and technology spillovers from FDI and promote sustainable long-term economic growth. This study is significant because it contributes to the literature on determinants of FDI by extending the scope of previous studies that often focused on BRICS only

    Multiangulation position estimation performance analysis using a Bartlett’s Beamforming Method

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    In this work, a complete multiangulation system was developed and its performance in term of position estimation (PE) was determined. The developed system uses Bartlett’s beam forming method to estimate AOA of the signal impinging on the 16-element sensor array in a uniform linear array (ULA) geometry at each ground receiving station (GRS). The AOA measurements are then used as input to a linear angulation algorithm for PE. The PE accuracy of the developed system was determined using Monte Carlo simulation and compared with the directional rotating antenna multiangulation system using a square GRS configuration. Simulation results shows that the developed multiangulation PE error is 50% lower than that of the directional rotating antenna system. Furthermore, the PE error of the developed system is higher for emitting sources within the system coverage with position bearings within 610 to 1200 and 2400 to 3000 than other emitting source locations.Keywords: multiangulation system, position estimation, beam forming, Monte Carlo Simulation, position bearin

    Time of arrival 3-D position estimation using minimum ADS-B receiver configuration

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    The location from which a signal is transmitted can be estimated using the time it takes to be detected at a receiver. The difference between transmission time and the detection time is known as time of arrival (TOA). In this work, an algorithm for 3-dimensional (3-D) position estimation (PE) of an emitter using the minimum receiving stations configuration was developed. The TOA measurements estimated from three automatic surveillance dependent broadcast (ADS-B) receivers are used to evaluate the performance of the PE algorithm. The result shows that the triangular ADS-B receiver configuration is capable of 3-D PE for emitter locations within 190 km coverage radius and that the altitude estimation error is 2 km higher than the horizontal coordinate estimation error. Within the 3-D PE coverage of the ADS-B receiver, the maximum horizontal and altitude error expected are 0.12 km and 2.2 km respectively.Keywords: TOA, ADS-B, position estimation, minimum configuration, surveillanc

    Bibliometric Analysis of International Journal of Research in Education, 2004 – 2012

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    This study is a bibliometric analysis of the International Journal of Research in Education for the period between 2004 and 2012. The authors have tried to analyse the number of articles, authorship pattern, bibliographical forms of citations, geographical distribution of authors, authors’ institutional affiliations, citation pattern, subject coverage, etc. The study reveals that 347 articles were published during the period. 226(65.1%) articles were contributed by single authors while the rest 121 (34.9%) were by joint authors. The study also revealed that 94.2% of the contributions are from Nigeria. Majority (40.9%) of the contributors preferred books as source of information. Universities topped ranking of institutional affiliations of contributors with 41.8%. Finally, curriculum and teaching is the most researched subject. Keywords: Bibliometric analysis, Authorship pattern, Citation pattern, Geographical distribution

    Virtual synchronous generator: an overview

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    The continuous increase in the penetration of renewable energy (RE) based distributed generations (DGs) in the power system network has created a great concern on the stability of the existing grid. Traditional bulk power plants, which are dominated by synchronous machines (SMs) can easily support system instability, due to the inherent rotor inertia and damping characteristic, as well as voltage (reactive power) control ability. Nevertheless, converter based RE has some special characteristics, such as stochastic real and reactive power output, quick active and reactive power response, small output impedance, and little or no inertia and damping property thereby causing frequency and voltage instability in the system. To solve this problem, virtual synchronous generator (VSG) concept was proposed to emulate some of the features of conventional SG through converter control strategy in order to provide additional inertia virtually. Different control schemes for VSG has been proposed in literature. Surprisingly, an overview of these schemes is yet to be efficiently presented. This paper presents an overview of the VSG control schemes. It provides the concepts, the features of the control schemes and the applications of VSG. Finally, the crucial issues regarding VSG control schemes and the necessary improvement that need to be addressed are highlighted.Keywords: Distributed generation, Synchronous generator, Virtual synchronous generator, Power electronicv converter, Energy storage system, Frequency contro
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