138 research outputs found

    Preliminary investigations of Njuwa Lake, Adamawa State, for fish production enhancement and resuscitation of Njuwa annual cultural fishing festival

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    Lake Njuwa has a historical and cultural heritage and has been a veritable source of livelihood to the people of Yola town on the South-western side, and Rugange village on the North-eastern side of the lake. Many Rivers and streams flow into the Lake. From the South Western side River Chouchi and Mayo Chudde; from the South Eastern side by numerous streams such as Mayel Lumo, Mayel Kalwa, Mandare streams and many other small streams (about five) drain into Njuwa Lake. The major contributor to the Lake is a "neck" in the North Eastern side of the Lake which emanates from Benue River. When River Benue is full especially when Lagdo spill gates are open in September, the neck allows water from the back-flow of Benue to enter the Lake and with it comes the recruitment of the Lake's fish species diversity Preliminary investigation revealed that Njuwa Lake despite its numerous environmental problems which sometimes leads to its complete drying, has very ideal limnological parameters for fish production. Njuwa was reported to be 17.5km2 (17500m2) before the construction of Lagdo dam on River Benue on the Nigeria-Cameroon boarder by the Cameroonian Authorities and the numerous irrigation projects around the Lake and River Benue. As at December 1981 however, aerial photos showed that it had shrunk to 3.5 km (3,500m2). As at November 2004, it has completely dried up. It was reported that cars could actually drive through on the dry bed of the Lake. The average depth of the Lake is around 0.5 meters and the water is very turbid. Farming around the Lake has triggered a higher level of deposit into the flood water which serves as silting material for the Lake. This is in addition to farm chemicals run off from the rain fed and irrigated crop, increasing the nutrient supply to lake's water thereby leading to accelerated eutrophication with it adverse consequences. Fish species diversity is also very high from on site report. Therefore the lake offers a unique potential for both artisanal fishing and fisheries tourism through the resuscitation of the cultural fishing festival despite the environmental degradation that it has suffered over the years. In view of the great prospects of the Njuwa Lake basin, if properly developed for its multidimensional benefits to the local economy in tourism job creation, food security, livelihood diversity and environmental improvement, the development of the lake basin on a holistic basis is highly recommended. The process should capture and involve the interest of all stakeholders around the Lake

    Investments and employment opportunities in the aquaculture sector in Nigeria

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    Nigeria is a large fish consuming nation with a total consumption at more than 1.2 million tonnes, with fish imports making up about two thirds (700,000 t) of the fish supply. Although the contribution of fisheries to the Gross Domestic Product is only 3-4%, it occupies a very significant position in the primary sector providing employment for over a million people (FDF Statistics) and contributing about 50% of the animal protein intake of the population, particularly the resource poor. The estimated national demand for fish is estimated as high as 1.3 million metric tons with a wholesale value of more than $US 1 billion. Of this, the Federal Department of fisheries (FDF) estimated 511,000 tones are provided domestically or only about one third of demand, with an estimated per capita fish consumption ranging from 7.5-12 kg. With the current policy thrust towards fisheries development, there is excitement among stakeholders in private sector fish farming as shown by the expansion and renovation of existing farms and investments in few fish farms and hatcheries. This has brought the industry to a retail production value of N180 million. This development is not however without some challenges. Fish producers have rushed ahead with the production without support of a developed values chain. This gap is providing an entry point for interventions to greatly facilitate expansion of services in the value chain for this exciting industry. This paper therefore seeks to provide guidance on how to strategically focus aquaculture activities to capitalise on opportunities for increased employment and incomes

    Cyclist Performance Classification System based on Submaximal Fitness Test

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    Performances among cyclist always measured by time traveled from start to finish line and then the winner in cycling event also decided by time or who crossed the finish line first. On the other hand, cyclist performance can be measured through cardiorespiratory and physical fitness, and this performance can be enhanced by proper training to increase fitness and skill without burden. A wireless sensor network (WSN) system developed by combined various sensing element to capture physiological and bicycle’s kinetics feedback. Physiological data such as heart rate variability (HRV) and kinetic data such as paddling power and cadence used as input in Astrand-Ryhming and PWC150 submaximal test to classify the performance group among cyclist. Developed HRV system using Photoplethysmography (PPG) provides the significant output with R2 value was 0.967. A group of 15 cyclists from three different backgrounds was used as a subject in this study. Maximal oxygen intake (VO2max) produced by AstrandRyhming test correlated with estimated paddling power produced by PWC150 test with P<0.01 and the R2 value was 0.8656. Discriminant analysis was 88.3% successfully classified cyclist into 3 group and group of trained and untrained cyclist clearly separated

    Thermophysical Properties Of Nanocarbon Particles In Ethylene Glycol And Deionized Water

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    The recent research has demonstrated that nanofluids have provided significantly better thermophysical properties than the base fluids because of its novel properties. The nanofluids proved to have higher heat transfer property and specific heat capacity at a very low particle concentration than conventional heat transfer fluid. Generally, the available base fluid such as ethylene glycol (EG) and deionized water (DI) has a limitation in terms of thermophysical properties like thermal conductivity and heat transfer. An innovative way to overcome this limitation is by adding nanoparticles to the base fluid to form nanofluid. In this paper, the proposed objective is to formulate a stable nanofluid from HHT24 carbon nanofiber (CNF) and –OH functionalized multiwalled carbon nanotubes (MWCNT-OH) in a base fluid with the presence of polyvinylpyrrolidone (PVP) as the stabilizer through two-step preparation process. Then, the thermal conductivity and heat transfer were investigated at three different temperatures (6°C, 25°C and 40°C). Nanofluids tested for thermal conductivity and heat transfer shows that most of the samples achieved an enhancement in EG and DI based nanofluids when CNF HHT24 and MWCNT-OH particle was added. Overall, this studies shows that nanocarbon material is a great alternative to being used in conjunction with ethylene glycol and deionized water as a heat transfer media in a cooling application. 

    Modified Method For Generating B-Spline Curves of Degree Three And Their Controlling

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    The reaction between designer, and design needs modified methods to control the design. This paper presents modified mathematical technique for controlling the generation of the 2D designs of third degree, by using modified Gallier of Bezier curves. The paper discuses a polynomial in terms, of polar forms, with respect to the parameter. The modified method has resulted in good starting point, to generate which 2D design, algorithm which allows the designer to produce a design in combinational way allows him to get the shape that he has in his mind keeping the four control points for 2D design. The method shows a great flexibility in 2D design controlling area with changing. There is no need to change the control points of the design; moreover efficiency in designs is obtained in comparison with that needed for conventional methods. Keywords: Gallier of Bezier curves, B-Spline Curves

    Investigation of thermal characteristics of CNF-based nanofluids for electronic cooling applications

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    A major problem being faced by existing coolants is the limited amount of heat that can be absorbed by the fluids. An innovative way to overcome this limitation is by utilizing a nano-coolant as a heat transfer medium in a cooling application. This paper was aimed at formulating an efficient nanofluid from Pyrograf III HHT24 carbon nanofibers (CNF) in a base fluid consisting of deionized water (DI) and ethylene glycol (EG) with polyvinylpyrrolidone (PVP) as the dispersant. The experiment was conducted by setting the variable weight percentage of CNF from 0.1 wt% to 1.0 wt%, with the base fluid ratio of 90:10 (DI:EG) weight percent. Then, the thermal properties of the formulated nanofluids were investigated. The test on the thermal conductivity of the nanofluids showed that the highest thermal conductivity of 0.642 W/m.K in this experiment was produced when the concentration of nanofluid is 0.5 wt% at a temperature of 40°C. Experimental investigations into the forced convective heat transfer performance of the CNF-based nanofluid in a laminar flow through a mini heat transfer test rig showed that the presence of nanoparticles enhanced the heat transfer coefficient as opposed to the original base fluid. The highest heat transfer coefficient was reported using nanofluid with a concentration of 0.6 wt% at 40°C. The enhancement of the heat transfer coefficient was due to the higher thermal conductivity value. The Nusselt number was also calculated and presented in this paper. This study showed that the CNF-based nanofluids have a huge potential to replace existing coolants in electronic cooling applications. Thus, in order to commercialize nanofluids in practice, more fundamental studies are needed to understand the crucial parameters that affect their thermal characteristics

    Thermal conductivity and viscosity of deionized water and ethylene glycol-based nanofluids

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    This paper focused on thermal conductivity and viscosity of deionised water and ethylene glycol-based nanofluids at three different temperatures (6C, 25C and 40C). For the preparation of nanofluids, a two-step method, comprised of homogenisation and sonication, was used on a mixture of MWCNT-OH, PVP and the base fluid. The results revealed that thermal conductivity was enhanced by about 8.86% for 0.8 wt% deionised water-based MWCNT-OH nanofluid, and by 5.37% for 0.2 wt% ethylene glycol-based MWCNT-OH nanofluid. Meanwhile, in viscosity test, the highest temperature of 40C exhibited lowest viscosity. This phenomenon happened only with ethylene glycol-based nanofluid, whilst the data on the viscosity of deionised water-based nanofluid was inconsistent at certain nanofluid concentrations. In conclusion, addition of MWCNT-OH into base fluid enhanced base fluid performance, giving it the potential to be used in cooling system applications

    Severity impact of a vapour cloud explosion (VCE) – Liquefied petroleum gas (LPG) road tanker accident

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    An explosion accident from a road tanker while carrying hazardous materials can have a dangerous effect on road users and the surrounding area through which the road tanker passes. Based on the evidence of the accident case involving the road tanker reported, it shows that this accident case can cause death and destruction to the surrounding property. In Malaysia, several cases of accidents involving road tankers have also occurred. Among the methods used to determine the impact of a road tanker explosion is the use of the consequences analysis method. Currently, there is limited number of software that can be used to determine the impact of a road tanker explosion accident that carries explosive chemicals such as butadiene, Liquefied Petroleum Gas (LPG), etc. However, there are weaknesses in the display of the impact results plotted on the map. Where the impact of the explosion is only shown to the 3 main zones, namely building damage, serious injury, and glass breakage. In this paper, the enhanced contour profile method on the impact of an LPG road tanker explosion on human and structural damage is shown
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