26 research outputs found

    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

    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

    Adsorption and Quantum Chemical Studies on the Inhibition Potentials of Some Thiosemicarbazides for the Corrosion of Mild Steel in Acidic Medium

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    Three thiosemicarbazides, namely 2-(2-aminophenyl)-N phenylhydrazinecarbothioamide (AP4PT), N,2-diphenylhydrazinecarbothioamide (D4PT) and 2-(2-hydroxyphenyl)-N-phenyl hydrazinecarbothioamide (HP4PT), were investigated as corrosion inhibitors for mild steel in H2SO4 solution using gravimetric and gasometric methods. The results revealed that they all inhibit corrosion and their % inhibition efficiencies (%IE) follow the order: AP4PT > HP4PT > D4PT. The %IE obtained from the gravimetric and gasometric experiments were in good agreement. The thermodynamic parameters obtained support a physical adsorption mechanism and the adsorption followed the Langmuir adsorption isotherm. Some quantum chemical parameters were calculated using different methods and correlated with the experimental %IE. Quantitative structure activity relationship (QSAR) approach was used on a composite index of some quantum chemical parameters to characterize the inhibition performance of the studied molecules. The results showed that the %IE were closely related to some of the quantum chemical parameters, but with varying degrees. The calculated/theoretical %IE of the molecules were found to be close to their experimental %IE. The local reactivity has been studied through the Fukui and condensed softness indices in order to predict both the reactive centers and to know the possible sites of nucleophilic and electrophilic attacks

    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

    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

    An assessment of cassava mosaic disease severity in cassava-maize mixture at different NPK levels

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    Trials were conducted at Uyo, Nigeria in 1995/97 to evaluate the impact of Cassava Mosaic Disease (CMD) on cassava when intercropped with maize. Observations at 3, 6, 9 and 12 months after planting (MAP) showed that CMD severity was generally low. The symptoms decreased from 3 to 9 MAP and then sometimes increased at 12 MAP. These variations were attributed to weather changes. CMD severities in all the cassava varieties were unaffected by cropping system or fertiliser (NPK) levels. TMS 30572 and TMS 89/00077 out-yielded the other two cultivars in intercropped and sole crops.Key Words: Cassava/maize intercropping, CMD, fertiliser level, Oyo State, tuber yieldRÉSUMÉ Des essais ont été conduits à Uyo, Nigeria en 1995/97 pour évaluer l'impact de la maladie de la mosaique du manioc (CMD) sur le manioc associé avec le maïs. Des observations faites (3, 6, 9 et 12 mois après plantations (MAP)) ont montré que la séverité du CMD était relativement faible. Les symptômes ont diminué de 3 à 9 MAP et puis augmenté de temps en temps à 12 MAP. Ces variations ont été attribuées aux changements des temps. Les séverités du CMD de toutes les variétés du manioc n'ont pas été affectées par les systèmes de culture ou les niveaux d'engrais (NPK). TMS 30572 et TMS 89/00077 ont dépassé en rendements les deux autres variétés en association et en cultures pures.Mots Clés: Association manioc/mais, CMD, niveau d'engrais, Etat d'Oyo, production des tubercules (African Crop Science Journal 8(3) 2000: 311-316
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