38 research outputs found

    Inhibition effect of Vernonia amygdalina extract on the corrosion of mild steel reinforcement in concrete in 0.2 M H2SO4 Environment

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    Inhibition effect of Vernonia amygdalina (bitter leaf) extract on the corrosion behaviour of embedded mild steel rebar in concrete immersed in 0.2% H2SO4 solution was investigated by potential measurement, pH and gravimetric methods using the extracts concentrations of 25, 50, 75, and 100%. The results were further analysed using the two-factor ANOVA test. Potential measurement was performed using a digital voltmeter and a copper/copper sulphate reference electrode. Compressive strength of each block sample was determined after the experiments. Weight loss values were obtained from the gravimetric method, and the inhibitor efficiency was computed from the corrosion rate of each of the tested samples. Results showed that varied concentration of V. amygdalina and the test exposure time significantly affect both the corrosion potential of embedded steel rebar in concrete and the pH of the medium. The extracts gave appreciable corrosion inhibition performance of the embedded steel rebar at 25 and 50% concentrations with the weight loss of 500 (0.5 g) and 400 mg (0.4 g) and corrosion rates values of 0.000240 and 0.000180 mm/ yr, respectively. The highest inhibition efficiency (60.68%) was achieved at 50 and 39.94% at 25% concentrations, respectively. The 100 and 75% concentrations gave negative inhibitor values of �51.52 and �20.11%. The ANOVA test confirmed the results at 95% confidence, and further showed that concentration of V. amygdalina had greater effect on potential and pH measurement

    Farming Systems in Southeastern Nigeria: Implications for Sustainable Agricultural Production

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    This study examines the farming systems in southeastern Nigeria. Using a structured questionnaire, 300 farmers were selected through multistage random sampling techniques. The data collected were subjected to descriptive analysis of simple proportions and percentages. Findings from the study revealed that 72% of the respondents engaged in both crop and livestock production. Intercropping was the dominant cropping system with cassava, yam, and maize as the principal arable crops, while cocoa, kolanut, oil palm, rubber, cashew, banana/plantain and citrus were the main permanent crops. The dominant fallow period was found to be three to four years and most farm sizes were less than 2 hectares. The study also showed that 88% of the respondents knew of fertilizer, 61% knew of other agrochemicals, while 56% and 16% utilized them, respectively. Findings generally point to inefficiencies in some of the existing farming practices. Addressing the constraints identified in this study may improve the farming systems in the study area and thus increase agricultural production on a sustainable basis

    Forage Yield and Nutritive Quality of Haulm from Dual-Purpose Cowpea (\u3ci\u3eVigna unguiculata\u3c/i\u3e L Walp) Cultivars for Dry Season Feeding in Nigeria

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    The availability of high quality forage especially during the dry season remains a major challenge to ruminant livestock production in Nigeria and many parts of West Africa. Due to the prevailing mismatch between livestock population and supply of feed resources in the arid and semi arid Nigeria, the humid forest zone represents a potential source for crop residues, especially during the dry season due to longer rainfall duration and suitable climate. This study was conducted to evaluate forage yield and nutritive quality of haulm from selected dual purpose cowpea (Vigna unguiculata L. Walp.) cultivars in the humid rain forest zone of Nigeria. The forage and pod yields of twenty cultivars were evaluated in two cropping seasons of 2012 and 2013, in a randomized complete block design with three replications. Subsequently, five dual-purpose cultivars were selected based on forage and pod yields from previous trial, for determination of chemical and fibre compositions. The results revealed significant (p \u3c 0.05) differences in pod and forage yields among the twenty cowpea cultivars, with mean yields ranging from 0-1.5 t ha-1 and 0.1-4.5 t ha-1 for pod and forage respectively. The results also showed significant (p \u3c 0.05) differences in crude protein, ether extract, and non-fibre carbohydrates (NFC) contents amongst the five selected cultivars. The selected cultivars are recommended as dual-purpose cowpea for the zone. The result reveal wide implications for commercial production, processing and packaging of cowpea and other related forage crops for sale in Northern Nigeria where demand for dry season feedstuff outstrips supply. In addition, availability of feedstuff during the dry season is capable of promoting sedentarization of nomadic pastoralists and the attendant conflict associated with that system of livestock management

    Bio-oil production from co-pyrolysis of rice husk and plastic waste

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    Bio-oil has been produced from the co-pyrolytic reaction of rice husk and 2 grades of plastic wastes (LDPE and PET). The effect of catalysis on the yield was considered while the physicochemical properties of the products were evaluated and a comparison drawn between the properties of the oil and that of the commercial grade diesel. FT-IR and GC-MS analysis were also used to characterize the samples. Furthermore, the performance of a DI diesel engine was evaluated using both grades of oil. Results showed an improved yield of the oil through catalysis. The heating value and cetane number of the pyrolysis oil closely compared with commercial-grade diesel. Chemical compound identification through the GC-MS analysis showed the bio-oil to comprise mainly of aliphatic and aromatic hydrocarbons. FT-IR analysis of the by-product bio-char upon comparison with FT-IR analysis of the rice husk biomass confirmed the chemical modification of the biomass after the pyrolysis process.  From the result of this work, co-pyrolysis of both feedstock gave rise to high grade oil whose properties compares favorably with the commercial grade diesel. This is therefore an interesting alternative to fossil fuel whereas the improved properties indicate that it could have a better performance than a single biomass in terms of fuel properties

    Evaluation of sesamum gum as an excipient in matrix tablets

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    In developing countries modern medicines are often beyond the affordability of the majority of the population. This is due to the reliance on expensive imported raw materials despite the abundance of natural resources which could provide an equivalent or even an improved function. The aim of this study was to investigate the potential of sesamum gum (SG) extracted from the leaves of Sesamum radiatum (readily cultivated in sub-Saharan Africa) as a matrix former. Directly compressed matrix tablets were prepared from the extract and compared with similar matrices of HPMC (K4M) using theophylline as a model water soluble drug. The compaction, swelling, erosion and drug release from the matrices were studied in deionized water, 0.1 N HCl (pH 1.2) and phosphate buffer (pH 6.8) using USP apparatus II. The data from the swelling, erosion and drug release studies were also fitted into the respective mathematical models. Results showed that the matrices underwent a combination of swelling and erosion, with the swelling action being controlled by the rate of hydration in the medium. SG also controlled the release of theophylline similar to the HPMC and therefore may have use as an alternative excipient in regions where Sesamum radiatum can be easily cultivated

    Nanoscale Visualization of Elastic Inhomogeneities at TiN Coatings Using Ultrasonic Force Microscopy

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    Ultrasonic force microscopy has been applied to the characterization of titanium nitride coatings deposited by physical vapor deposition dc magnetron sputtering on stainless steel substrates. The titanium nitride layers exhibit a rich variety of elastic contrast in the ultrasonic force microscopy images. Nanoscale inhomogeneities in stiffness on the titanium nitride films have been attributed to softer substoichiometric titanium nitride species and/or trapped subsurface gas. The results show that increasing the sputtering power at the Ti cathode increases the elastic homogeneity of the titanium nitride layers on the nanometer scale. Ultrasonic force microscopy elastic mapping on titanium nitride layers demonstrates the capability of the technique to provide information of high value for the engineering of improved coatings

    Drivers of diversification and pluriactivity among smallholder farmers—evidence from Nigeria

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    Diversification and pluriactivity have become a norm among farm business owners (FBOs) due to persistent low farm income. This study applies the resource-based theory to examine drivers of diversification and livelihood income-oriented towards a sustainable livelihood. Our framework develops hypotheses about the impact of internal and external resources on livelihood choices at the household level. We use a survey of 480 rural Nigerian farmers (agripreneurs), applying a Multivariate Tobit to test our framework. We find that education plays the most significant role in all types of employment options. The more FBOs are educated, the more the likelihood that they will choose non-farm or wage employment. This study revealed that while the agriculture sector’s share of rural employment is declining, non-farm is on the increase. More so, there is a decline in farming among the young generation, marital status bias and gender influence in resource allocation. The socioeconomic (income and food security) and socio-cultural (employment and rural-urban migration) implications of rural sustainability linked to UN Development Goals have been highlighted and analysed in this article

    Technical and allocative efficiencies of small-scale cassava growers in five selected local government areas of Cross River State.

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    In this paper, the single equation estimation technique using the ordinary least square (OLS) multiple approach was used to estimate the relationship between farm size and such factors as Capital, Labour and Education of Small Scale Cassava growers in five Local Government Areas of Cross River State. In addition, technical and allocative efficiencies as well as resource elasticities were estimated based on the results of the specified production functions. The R2 (which is the explanatory power) for the production was .71. For the estimated marginal value product functions, the R2 ranged from .29 to .40. Two of the explanatory variables in the production function, land and labour were significant at the 95% confidence level. The results of the marginal value products functions indicated an inverse relationship between productivity and farm size while technical and allocative efficiencies for land, show that the relatively smaller farm sizes were more efficient. Resource elasticities were also found to be inelastic implying that strategies aimed at decreasing resource prices to improve productivity of cassava growers would have minimal effect. Global Journal of Pure and Applied Sciences Volume , No 1 January (2001) pp. 37-42 KEY WORDS: Technical, Allocative, Productivity, efficiency

    The use of five techniques to extract protein, oil and gossypol content of Okra seeds (Abelmosches esculentus (L) moench

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    No Abstract.Global Journal of Pure and Applied Sciences Vol. 11(4) 2005: 449-45
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