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The study critically reviews the prospects and challenges of utilizing wind energy resources for power generation in Nigeria. The various initiatives by governments and researchers were surveyed and the nation is found to sit in the midst of enormous potential for wind harvest for power generation. The far northern states, the mountainous regions and different places of the central and south-eastern states were identified as good areas for wind harvest together with the offshore areas spanning from Lagos through Ondo, Ogun, Cross-Rivers to Rivers states along the Atlantic Ocean in the south–south. Despite this great potential and huge prospect, the country is found to still suffer from serious energy crises due to her over dependence on hydropower which also is susceptible to seasonal variation in the amount of water levels at dams. There is yet to be committed wind energy project for power generation on-going in the country. Several challenges bedeviling the development and utilization of wind energy resources were identified and suggestions highlighted to help pull the nation out of this lingering energy crisis.  相似文献   
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The effects of glycerol monostearate (GMS) and sodium steroyl lactylate (SSL) on the rheological properties of native, naturally fermented (NF) and mixed culture fermented (MCF) cassava flour pastes were measured using instrumental texture profile analysis (TPA) and by finger cohesiveness (difficulty in separation). Fermentation reduced the TPA parameters, hardness, cohesiveness and gumminess, but not springiness/elasticity. These were reduced further when either GMS or SSL were incorporated into the pastes. Pastes made from native and naturally fermented flours were scored by a Cameroonian sensory panel as difficult to separate, whereas scores for native and fermented flour pastes treated with 1% or more of GMS or SSL were easy to separate. Increased internal stability of the cassava flour starch granules was suggested as the cause of the effects.  相似文献   
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Urban space administration is a branch of public administration designated for ordering, re-ordering, regulating and controlling urban systems and urban land uses for the purpose of human comfort, convenience, urban aesthetic or city’s branding and economic and environmental sustainability. Urban space administration is not new in Nigeria; it dated back to precolonial periods when city management was vested in kings and a team of advisers including the local priests. The advent of colonial government introduced paper-assisted urban administration which continued after independence. The 1976 local government reforms and the subsequent fragmentations of states to many local government resulted in multiplicity of admirations and agencies governing urban areas in Nigeria. The results are manifested in blighted condition and pockets of slums in all Nigeria cities. The paper examined trends in urban administration in Nigeria and advanced two approaches to solving multifarious urban problems in Nigeria. The approaches include devolution of urban administration powers to local authorities and deployment of geospatial technology tools for urban system administrators ( Knaap et al 1998). The paper further suggested recommendations for bridging the digital shortfall in the applications of modern technologies to city administration in Nigeria.  相似文献   
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The paper examines the performance of Modified Manchester (MM) modulation scheme over wavelength division multiplexing (WDM) in high-speed optical communication links. The MM as a new modulation technique has a narrow spectral width compared to conventional Manchester coding, which allows its implementation in WDM systems beneficial. In this study, the performance characteristics of MM and conventional Manchester modulation formats are assessed in WDM system at 10 Gb/s bitrate for each channel, for the least allowable channel spacing as well as tolerance to chromatic dispersion (CD). It is revealed from the results of simulation that MM performs meaningfully well in comparison with conventional Manchester in terms of tolerance against narrow optical filtering, spectral efficiency, which is improved by 32% and CD tolerance, which is improved by +100 ps/nm. Sixteen wavelength channels (16 × 10 Gb/s) are modulated to provide 160 Gb/s data capacity, which was transmitted successfully over 224 km standard single mode fibre (SSMF) using MM while the conventional Manchester only covered about 157 km.  相似文献   
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We propose a flexible decision support scheme which could be used in managing the wage negotiation between employers and employees. This scheme uses fuzzy inference systems and game theory concepts in arriving at decisions on future wage increase which could be more mutually agreeable. For example, rather than specifying 5% yearly increase of wages, we propose that the uncertain factors which are mostly difficult to predict and that could affect wage decisions need to be taken into consideration by the wage formula. These include business revenues or (profit), inflation rate, number of competitors, cost of production, and other uncertain factors that may affect business operations. The accuracy of the fuzzy rule base and the game strategies will help to mitigate the adverse effects that a business may suffer from these uncertain factors. Based on our scheme, we propose that employers and employees should calculate their future wage by using a fuzzy rule base and strategies that take into consideration these uncertain variables. The proposed approach is illustrated with a case study and the procedure and methodology may be easily implemented by business organizations in their wage bargaining and decision processes.  相似文献   
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Polybenzoxazines are high-performance materials capable of replacing conventional thermosets such as phenolics, epoxies, and bismaleimides in composites manufacturing due to their excellent thermomechanical and chemical behavior. Their versatility and compatibility with biobased precursors make them an attractive option as composite matrices. Like other thermosets, polybenzoxazines are not recyclable and cannot be reprocessed. Incorporating dynamic bonds in benzoxazine monomers can produce vitrimeric polybenzoxazines, which can potentially overcome this limitation and can be tuned to exhibit smart functionalities such as self-healing and shape memory. Dynamic bond exchange mechanisms for vitrimer development such as transesterification, imine bond, disulfide exchange, transamination, transcarbamoylation, transalkylation, olefin metathesis, transcarbonation, siloxane-silanol exchange, boronic ester, silyl ether exchange, and dioxaborolane metathesis are potentially applicable to benzoxazine chemistry, with disulfide bond and transesterification having successfully vitrimerized benzoxazines with topological transitions at −8.5 and 88 °C, respectively. Benzoxazine vitrimers featuring glass transitions of 193, 224, and 222–236 °C are now known. These place polybenzoxazines at the forefront of the development of reprocessable and recyclable thermosetting polymers and composite matrices.  相似文献   
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The study assessed the feasibility and economic viability of solar and wind energy resources as sustainable electrical source for rural communities unconnected to the grid. Rural communities made up of 200 homes, a school and health centre were conceived. Specific electric load profile of 358?kWh per day, with 46?kW primary peak load and 20?kW deferrable peak load, was formulated to match the rural communities. The assessment of the design that will optimally meet the daily load demand with a loss of load probability of 0.01 was carried out by considering three stand-alone applications of photovoltaic (PV), wind, diesel, and a hybrid design of wind-PV. The result showed that a cost-effective alternative for power generation at the different sites surpassed the conventional diesel stand-alone system. Also, the embedded generation analysis showed that 5 of the 6 configurations yielded profits for a 10-year project life in line with the present national tariff order.  相似文献   
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