The seed coats of jack beans (Canavalia ensiformis) were pulverized and modified via mercerization process. The chemical properties, morphology, Fourier-Transform InfraRed spectroscopy (FTIR) spectra and X-ray patterns of the unmodified and modified samples were studied. The unmodified sample was more acidic and hydrophilic than the mercerized sample. The iodine absorption number of the unmodified sample was 1.98 ml while the mercerized was 1.00 ml. The micrographs of unmodified sample showed irregular shapes of the granules while those of the mercerized derivative were mixes of cylindrical and rod-like shapes, which appeared more crystalline and fibrous than the unmodified. The mercerized sample showed (O-H) spectra of normal polymeric hydroxyl group, which had a characteristic signal of lignocellulosics. In addition, absorption band 2129.24 cm-1, indicating –C≡C– terminal alkynes (mono substituted), was found in the mercerized sample. Very strong N–O of nitro group was observed at 1540.26 cm-1, which disappeared upon modification. The XRD profile showed peaks of both the modified and unmodified as mixes of A- and B- polymorphs, that is, C-type, with high proportion of silicone. The X-ray patterns were unchanged after modification. However, the crystallite size of the unmodified sample increased from 8.60 to 10.10. Therefore, the mercerized fiber were more applicable in the fabrication of fiber-polymer composites than the unmodified fiber.
Engineering properties of soils is useful in understanding the properties and behaviour of soils for the management especially erosion control, farming activities, building, etc. The present research was aimed to assess the engineering properties and behavior of the soils in Otukpo local Government Area of Benue State. The engineering properties such as Atterberg limits (e.g., shrinkage limit, liquid limit and plastic limit), bulk density, dry density and optimum moisture content, particle size distribution within were determined from four districts in the Local Government Area. The samples collected from three different points in each district were mixed together and analysed in the SCC Nigeria limited control laboratory. Four samples were analysed, one from each district of Akpa, Uga, Ogboju, and Otukpo respectively. It was observed that Otobi and Obotu soils are uniformly graded, while the Owetor soils are well-graded while Uga soils are gap-graded. The obtained results indicate that the soils in the four districts are plastic. It was seen that the erosion menace in Otobi is not as a result of the nature of the soil. The problem may be due to management problem or poor cultural practice. The waterlogging menace was discovered to be due to high plasticity and fines nature of the soils in the research area. These reduce the infiltration capacity of the soil and eventually control soil erosion problems in the research area.
Energy play an influencing role in the development of key sectors of the nation's economy such as industry, transport and agriculture. Ethanol from cassava, a potential alternative and renewable fuel of the future, may required far more energy during its creation than its energy content after production.The energy requirement in the production of ethanol from cassava was determined, and pattern of energy consumption was investigated. A small scale dry-mill production process was set up for the production of the ethanol. Mathematical expressions were used to evaluate the energy requirement for each of the unit operations. Total energy input and output of cassava ethanol production were 38394.50MJ/ha and 28431.95MJ/ha, respectively. Energy use was 0.74, energy productivity was 0.034 and the Net Energy Value (NEV) was 0.75. This indicated that energy was not efficiently used and the fact that the NEV was less than 1.0 means that cassava ethanol production is not feasible from energetic standpoint and at a small scale level.
A hybrid energy system generally consists of two or more than two renewable energy sources and energy storage components used together to provide increased system efficiency as well as greater balance in electrical energy supply. In Algeria, a photovoltaic solar energy system has been widely utilized as an alternative energy source to fossil fuel at a residential area. The output of photovoltaic cell sharply changes according to weather conditions. Therefore, a certain power storage device is required to smooth the output and to meet electricity demand equivalent to a household load. A fuel cell is a promising candidate for long term energy system because hydrogen is supplied stably. The objective of this paper was to associate photovoltaic generators, fuel cells, and electrolysers. Here, to sustain the power demand and solve the energy storage problem, electrical energy can be stored in the form of hydrogen. By using an electrolyser, hydrogen can be generated and stored for future use. The hydrogen produced by the electrolyser using phtovoltaic (PV) power is used in the fuel cell (FC) system and acts as an energy buffer. Thus, the effects of reduction and even the absence of the available power from the PV system can be easily tackled.
A novel (E)-3-(2-P-Tolyldiazenyl)-1-nitrosonaphthalen-2-ol (NAD) has been synthesized and characterized via Fourier Transform Infrared (FTIR), UV/Vis, 1H-NMR and 13C-NMR spectroscopic techniques. Weight loss analysis showed that this molecule possesses excellent corrosion inhibitive potentials. Variations of inhibition efficiency with concentration and temperature were observed and the results obtained show that inhibition efficiency increases with increase in concentration while it reduces with an increase in temperature. The efficiency of this molecule was validated with theoretical models using the density functional theory (DFT) method with the hybrid functional, Becke Three Lee Yang Parr (B3LYP) correlation with 6-31G* basis set. It was observed that the molecule has very good corrosion inhibitive potentials.
Spectroscopic and electrochemical properties of 4-(2-aminoethylthio phthalocyanato complexes of cobalt (complex 3) and manganese (complex 4) were investigated. The UV-Vis spectral properties of the complexes were typical of the nature of central metal (cobalt versus manganese) phthalocyanine. The Q-band of manganese 4-(2-aminoethylthio) phthalocyanine is red shifted with respect to cobalt manganese 4-(2-aminoethylthio) phthalocyanine. Solution electrochemistry of complex 3 showed three distinctly resolved redox processes attributed to (), () and / ( ). No ring based oxidation was observed in complex 3. Complex 4 showed both ring-based oxidation, attributed to ( ) and ring-based reduction associated with ( ), with the normal metal reduction, / ( ). The cathodic to anodic differences (E) of redox processes observed for 4 are 180mV and 130 mV while the cathodic to anodic peak difference (E) for 3 are 290 mV and 210 mV at processes I and II. By virture of this, manganese 4-(2-aminoethylthio) phthalocyanine complex has better electron transfer processes than the cobalt analogue.
The purpose of this to produce efficient numerical methods with the same order of accuracy as that of the main starting values for exact solutions of fourth order differential equation without reducing it to a system of first order differential equations. The methods of the differential systems arising from the approximate solution to the problem are adopted using the Runge-Kutta method and stages. The methods were compared and contrasted based on the results obtained. The comparison shows that Euler method gives accurate approximate result than Runge-Kutta method. After the derivation of the formulae of O(h2), the comparison was done in regards to identify the formula with higher accuracy.
The concept of harmonic oscillator particularly one dimensional (1-D) is mentioned in literature repeatedly and is explained in more complex manner by using various methods. This creates difficulties in understanding the description of the concept for new learners. The purpose of this article was to enlighten different methods to formulate harmonic oscillator in improving knowledge about detailed steps to derive eigen energy values in more comprehensible manner for the beginners. The energy values are derived by using classical method, quantum mechanically, Schrodinger time independent equation, perturbation technique, variation method, WKB approximation etc. A coherent way of derivation of eigen values using various approaches makes this article as unique.
The study was carried out to optimize the filtration of the hydrolysis cake obtained during the refining stage of platinu-rich liquor. The platinum refining stage cake was first filtered in the glove box and secondly in the filter press to optimize the recovery of platinum value. The results obtained indicated that the filter press operation gave the highest and lowest platinum recovery efficiencies of about 99.95 and 97.69% as against 99.39 and 97.21%, respectively, for the glove box. In addition, the trend lines obtained showed that the filter press operation results following almost a linear trendline as being more stable than the glove box with a steeper trendline. Furthermore, the filter press processing of the hydrolysis cake took only about five hours in comparison to about 14 hours for the glove box. The filter press has thus proven to be a more efficient method to optimize platinum recovery from hydrolysis cake.
A new efficient hybrid differential evolution algorithm with harmony search (DE-HS) is proposed in this paper to solve the economic load dispatch (ELD) problem. The fresh individual generation mechanism of harmony search (HS) is utilized to enhance the local search capability of the original differential evolution (DE) method. The proposed hybrid algorithm is validated using the IEEE 30 bus test system and the practical Algerian 59 bus system. The results confirm the suitability of the proposed strategy to find accurate and feasible optimal solutions for ELD problems.
Aim: The study evaluated the relevant/corresponding anthropometric characteristics of the people involved in engine-repair activities. The study was carried out on the selected roadside auto-engine repairers along Lagos-Ibadan express way, in Nigeria. This was with a view to providing ergonomic design data for optimal working condition among this set of workforce and redesigning the mechanics inspection-pit. Material and methods: The static and the functional anthropometric characteristics of the mechanics were measured. The data obtained from 110 auto-mechanics, randomly selected, were employed to evaluate efficient design parameter for roadside workstations. Results: The results indicated that inspection-pit is about 1626 mm deep; seat height ranges between 375 mm and 405 mm; optimal work posture sitting is between 483 mm and 622 mm. Conclusions: Adopting the data presented in this paper in optimizing the auto-mechanics working conditions for effective workplace comfort and productivity among the roadside auto-mechanics in Nigeria will be of immense advantage.
Datura stramonium leaf extract (DSLE), as corrosion inhibitor in 1M HCl acid solution was assessed using phytochemical screening, atomic absorption spectroscopy (AAS), gravimetric (mass loss), and electrochemical (Tafel and potentiodynamic polarization) methods. The extract was found to efficiently inhibit the corrosion process and the inhibition efficiency increased with increasing extract concentration (over 400% increases) at room temperature. The maximum inhibition efficiency of DSLE in 1M HCl was found to be 98.69% at 0.5g/l concentration. The potentiodynamic polarization results revealed that DSLE functioned as mixed-type inhibitor acting on both the anodic and cathodic sites (but predominantly anodic control). The AAS analysis shows that the concentration of Fe2+in the electrolyte decreases with increase in the extract concentration. The adsorption studies of the extract on the metal surface showed that there was a physiosorption process as the concentration increases and the chemisorption process is also prevalent. The adsorption studies fitted the assumptions of Temkin and Freundlich isotherm models.
The methodology of resources allocation and the mathematical description of the problem are presented. The problem is founded in the class of linear programming models and the modified simplex method to find optimal solutions is designed. An example is given to illustrate the implementation of the developed methodology.
Asbestos has been used for so long as automobile brake lining material because of its good physical and chemical properties. However, due to the health hazard associated with its handling, it has lost favour and several alternative materials are being increasingly used. Asbestos-free brake lining was developed in this work using pulverized cow hooves along with epoxy resin, barium sulphate, graphite and aluminium oxide. This was with a view to exploiting the characteristics of cow hooves, which are largely discarded as waste materials to replace asbestos which has been found to be carcinogenic. Samples of brake linings were produced using compressive moulding in which the physical and mechanical properties of the samples were studied. The results obtained showed that proper bonding was achieved as the percentage by weight of epoxy resin increased and percentage by weight of pulverized cow hooves decreased. The hardness, compressive strength, coefficient of friction, water and oil absorption, relative density and wear rate of the brake linings were determined and compared with existing brake lining properties. The result indicates that pulverized cow hooves can be used as brake lining material for automobiles.
The optical properties of multi-layers thin films, to be used as resonator for Nd:YAG, is studied in this work via computer simulation. The output coupler was designed to be fabricated by successive thin layers to achieve very high transmittance at optical wavelengths around 1064 nm for Nd:YAG laser. In addition, different optical filters were examined to control the transmittance and reflectance for the same laser wavelength. Three samples of dielectric materials composed of HgS/Na3AlF6, HgS/MgF2, and CdS/Na3AlF6 were used and compared with each other in transmittance, reflectance, physical thickness, optical thickness and full width at half maximum. The results showed that the best transmittance was achieved with HgS+Na3AlF6 where the transmittance for 1064 nm increased to 95.74 %.
Since botanicals still remained the most promising tool that could obviate the use of chemical insecticides, this study investigated the biotoxic effect of Acacia auriculiformis and Acalypha goddsefiana powder and oil against Sitophilus oryzae. The powder of the plants were tested at 0.0g (control), 0.1, 0.2, 0.4, 0.6, 0.8, 1.0 and 2.0g dosages while their extracts were prepared at 1, 2, 3, 4 and 5% concentrations per 20g of maize seeds. Solvent control was also prepared for the oil extracts bioassay. Mortality, adult emergence, % inhibition rate and % weight loss were observed. LD50 and LC50 of the powders and oils of the two botanicals were calculated at 48 hours of application. The powders of both plants achieved complete weevil mortality within 72h of application at 2.0g and their effect was significantly (p<0.05) different from other dosages except 1.0g dosage. Also, the extracts of both plant achieved 100% insect mortality within 48h hours of application at 5%. However the powder and oil of A. auriculiformis appeared more effective than that of A. goddsefiana in term of mortality as reflected by their lethal dosage and concentration. However, A. goddsefiana powder and extract appeared more effective than that of A. auriculiformis in term of protectability as they greatly reduced the emergence of the adult weevil and their ability to cause weight loss of the maize grains. Only the higher dosages and concentrations of the plants were able to achieve 100% inhibition rate.
Identification of the precise nature and attributes of the time series of climatological data is very important and is usually the first step of water resources planning and management. The major objective of this study was to determine the presence or otherwise of trend over time for some selected hydro-climatic components of Kaduna, Nigeria, and deduce the magnitude. Statistical approaches were used to investigate the presence and extent of persistence, trend analysis in hydro-climatic time series. Based on Mann Kendall test, twenty six years of hydro-climatic data were used. The non-parametric Man-Kendall test was used to detect monotonic trends, and the Mann-Kendall slope estimator was used to estimate the magnitude of trend on the variables. An evidence of trend was observed in all variables. Temperature and evaporation variables showed a positive and significant trend over time, while rainfall and stream flow had negative trend though not significant at the 95 % level of confidence. Thus, it could be concluded that the trend of change in temperature around River Kaduna is on the increase, with no significant increase in change of rainfall.
Chemical activation was carried out on the kaolin clay obtained from Kpautagi Area in Niger State using sulfuric and hydrochloric acids. In order to study the effect of acid activation, the physicochemical characteristics of the Kpautagi clay were determined before and after acid modification and the results obtained were subsequently compared. These characteristics include surface morphology, surface functional groups, surface area and pore volume. Characterization results showed that acid modification of Kpautagi kaolin clay with sulphuric and hydrochloric acids improved the surface area of the clay from 7.598m2/g to 15.5cm2/g and 13.2cm2/g respectively and enhancement in pore volume and average pore diameter were also noted. The changes in the characteristics of the clay after acid modification were further supported by the Scanning Electron Microscope (SEM) micrographs and Fourier Transformed Infrared Spectroscope (FTIR) spectra. Therefore, the outcome of this study shows that sulphuric and hydrochloric acid could be used to improve the characteristics of Kpautagi clay but better performance could be achieved employing sulphuric acid.
In this paper we consider the construction of implicit second derivative Runge-Kutta collocation methods designed for the continuous numerical solution of stiff systems of first order initial value problems in ordinary differential equations. These methods are obtained based on the multistep collocation technique, which are shown to be convergent, with improved regions of absolute stability. Although the implementation of the second derivative Runge-Kutta collocation methods remains iterative due to the implicit nature of the methods, the advantage gained makes them suitable for solving stiff systems with eigenvalues of large modulus lying close to the imaginary axis. Some absolute stability characteristics and order of accuracy of the methods are studied. Finally, we show two possible ways of implementing the methods and compare them on some numerical examples found in the literature to demonstrate the high order of accuracy and reliability of the methods.
The present work describes the effect of palm kernel shell ash (PKSA) as reinforcement on the mechanical properties of As-cast aluminium alloy. Recycled aluminium alloy from cylinder of an automotive engine block was degreased by using premium motor spirit (PMS) also known as petrol, washed thoroughly with soap and water and sun dried for 5 days. The palm kernel shell was screened of dirt and other unwanted foreign materials before being roasted in furnace. The ash was further pulverized by laboratory ball mill machine followed by sieving to obtain particle sizes of 106 µm and divided into two parts. One portion was treated with NaOH solution while the other part was left as untreated before they are used to reinforced molten aluminium alloy in predetermined proportions. The newly developed composites were characterized with respect to their mechanical properties in response to the tests that were carried out on them. The results indicate that palm kernel shell ash can be used as potential reinforcing material for automobile applications.