Kinetics of Anaerobic Co-Digestion of Paunch Manure and Sugarcane Peels using Cow Dung as Inoculum

Anaerobic co-digestion offers a prospective medium for transforming organic solid wastes into fuel, thereby providing an extra source of energy. This study investigates the kinetics of anaerobic co-digestion of paunch manure and sugarcane peels using cow dung as inoculum for biogas production. Anaerobic assay setup was in 3 digesters of 4 replicates with a total of 12 replicate batch digesters under mesophilic temperature range (30-35°C) for a retention time of 30 days. Cumulative biogas production for all digesters were measured and fitted to some selected models. The modified Gompertz equation was tested for its fitness. The kinetic parameters viz., biogas yield potential (P), maximum biogas production rate (Rm) and the duration of lag phase (λ) were recorded for each case as the digester with 0g sugarcane peels (control) produced maximum biogas of (83.14 (mL/g VS)) and the kinetic parameters P, Rm and λ were 89.0018 ml (g VS-1), 4.7089 ml (g VS d)-1, 0.8734 days respectively. It was observed that biogas production potential was inversely proportional to the substrate concentration of sugarcane peels in the digesters, the highest concentration of sugarcane peels (1.8g SP) recorded the lowest quantity of biogas with 37.9075 mL/g VS, 1.4547 g VS-1, 1.0891 days. Therefore, sugarcane peels should be co-digested with other substrates. The experimental kinetic data in-line with the Gompertz Model, Modified Gompertz Model Equation

Sb2Te3 crystal a potential absorber material for broadband photodetector: a first-principles study

Antimony telluride (Sb2Te3), a layered semiconductor material, is considered a promising absorbing material for a high-performance optoelectronic device within broadband wavelengths because of remarkable features like strong optical absorbance and the narrow direct band gap. In this work, based on the first-principles approach, we investigate in detail the structural, electronic and optical properties of the hexagonal Sb2Te3 compound. The structural and electronic properties were computed using the first-principles approach, treating exchange–correlation potential with generalized gradient approximation (GGA) within density functional theory (DFT). Furthermore, for accurate prediction of the band gap, we go beyond DFT and calculated band structure using GW correction. The optical properties, namely, imaginary and real parts of complex dielectric function, absorption coefficient, refractive index, reflectivity, extinction coefficient, electron energy loss function and optical conductivity are performed by quasi-particle many-body perturbation theory (MBPT) via Bethe-Salpeter equation (BSE). The computed structural parameters are in good agreement with available experimental data. The obtained quasi-particle (GW) correction band structure show the semiconducting character of Sb2Te3 material with a direct band gap Eg of 0.221 eV, in agreement with previously reported value (Eg = 0.210 eV) while the projected density of states indicates (PDOS) that the p-orbital of Sb and Te atoms are responsible for material properties near the Fermi level. To our knowledge, our first reported calculations of optical properties, with the inclusion of electron-hole effects are consistent with available experimental measurements. Consistencies of our findings with experimental data validate the effectiveness of electron-hole interaction for theoretical investigation of optical properties

Comparative Analysis of Monetary Policy Shocks and Exchange Rate Fluctuations in Nigeria and South Africa

The study examined a comparative analysis of monetary policy shocks and exchange rate fluctuations based on evidence from the two largest economies in Africa (Nigeria and South Africa) – from 1985 to 2015. Data were derived from various sources which include the National Bureau of Statistics, the Central Banks reports and the World Bank database. Vector Autoregressive (VAR) Analysis was used as the estimation technique. The results indicated that the foreign interest rate in South Africa had higher variations in the short-run. While in the long-run, foreign interest rate has higher percentage variations to exchange rate. In Nigeria the world oil price has the higher influence on exchange rate both in the short-run and longrun periods. Based on these results, the study then recommended that the monetary authorities and policymakers in both countries encourage external currency inflows into the economy. &nbsp

Physicochemical Characteristics and Fish Abundance and Diversity of Mairua Reservoir Water, Funtua, Katsina State, North-Western Nigeria

This research explores physico-chemical characteristics and fish abundance and diversity of Mairua Reservoir Water, Funtua, Katsina State, North-Western Nigeria. The duration of the study was 12 months starting from September to August, 2017, using standard methods and procedures.The result revealed that; Water temperature (25.02 ± 0.170C) pH (7.54 ± 0.03), Alkalinity (3.69±0.09), Conductivity (129.43 ± 5.15μЅ/cm), Total Dissolved Solids (50.54 ± 0.57mg/L) Nitrate-nitrogen (0.21 ± 0.04mg/L), Water Hardness (134.44 ± 3.06mg/LCaCO3), Dissolved Oxygen (3.98 ± 0.10mg/L),Biochemical Oxygen Demand (2.53 ± 0.08mg/L), Phosphate-phosphorus (0.19 ± 0.02mg/L),Chloride (5.09 ± 0.15mg/L),Sulphur-sulphate (0.21± 0.01) and Calcium (2.97±0.06mg/L) respectively were  all varied with months and seasons. Analysis of variance indicated significant difference between seasons (P < 0.05).Out of the total number of fish species (8273) identified; the result indicated Fish fauna percentage composition were Coptodon zillii: 1980 (23.9%), Clarias gariepinus: 1560 (18.9%), Oreochromis niloticus: 1020 (12.3%), Lates niloticus: 860 (10.4%), Bagrus. Bayad: 632 (7.6 %), Mormyrus senegalensis: 973 (11.8%), Labeo senegalensis: 595 (7.2%) and Synodontis clarias: 650 (7.9%). Results also indicates most of fish species were positively correlated with the water quality parameters in all the sites studied. Hence, there were fish abundance and a sustainable livelihood amongst the fishermen. However, a careful management strategy and routine monitoring from both government and non-governmental organizations are critical for the improvement and sustenance of the fisheries resources of the reservoir

Electronic and optical properties of Bi2Se3 topological insulator: a promising absorbing layer for broadband photodetector

Bismuth selenide (Bi2Se3) is a van der Waals compound which has been excellently reported as thermoelectric material. Linear dispersion near Fermi energy level is an exciting feature to consider, a promising candidate for photonic device within broadband wavelengths. For this application, detailed knowledge of its structural, electronic and optical properties is very essential. The electronic properties were determined by density functional theory (DFT) calculations implemented in Quantum-Espresso simulation package which uses plane wave basis and pseudopotential for the core electrons. Optical properties are computed by solving Bethe-Salpeter equation of many-body perturbation theory (MBPT) as implemented in Yambo code. The band structure results show the semiconducting behaviour of Bi2Se3. Taken into account the effects of electron-hole interaction by solving Bethe-Salpeter equation, the calculated optical properties are in better agreement with available experimental results. The exciton energy shows that the title material can absorb light within infrared region

Obesity and Insulin Resistance Components of Metabolic Syndrome Induced by High-fructose Diet in Wistar Rats could be attenuated by Spices-Supplemented Diets

Constant consumption of fructose-sweetened diets and beverages has led to increasing incidences of metabolic disorders such as metabolic syndrome (MS). This research was designed to evaluate the potentials of supplementing diets with some locally available spices in ameliorating obesity and insulin resistance in induced metabolic syndrome. Thirty out of thirty-five rats weighing 128.08±5.29g were induced with MS, divided into six groups and treated with diets supplemented with powders of garlic, ginger, turmeric, black pepper and equal mixture of the spices while the other 5 rats were maintained on normal diet throughout the experiment. The weight and blood glucose were recorded weekly, while serum insulin level was determined on the 56th day of the treatment after which HOMA-IR was computed. The group of MS-induced rats fed normal diet had significantly (p<0.05) higher weekly average weight gain of 11.43g±0.63g compared with other groups. Our data show that blood glucose level (mmol/L) ranged from 4.61±0.22 - 5.99±0.17; Insulin (μU/mL) 8.00±0.41 - 22.00±0.58 and HOMA-IR 1.65±0.14 - 5.47±0.07. The treated groups had significantly (p<0.05) higher percentage decrease in blood glucose and HOMA-IR when compared with the control but all the MS-induced rats maintained on supplemented diets had significantly (p<0.05) lower blood glucose and HOMA-IR when compared with MS-induced rats maintained on normal diet. From our finding, obesity and insulin resistance due to consumption of MS-causing diets could be ameliorated by consumption of diets fortified with any of the four spices, but fortification with a blend of the spices could give a better result

Renewable Energy and Sustainable Food Security in Nigeria

Renewable energy sources are becoming an increasingly important alternative source of energy in the agricultural sector. The use of renewable energy will reduce the use of fossil fuels, thereby minimizing the emission of green house gases. Increased use of renewable sources of energy especially in the agricultural sector will enhance the sustainability of food security in Nigeria and the quality of the environment. The use of renewable energy sources in the agricultural sector will also lead to environmentally friendly, sustainable and viable sources of energy to reduce the dependency on deplet­ing fossil fuels. Increasing attention is being focused on the installation and usage of renewable energy sources in the agricultural sector in several countries of the world purposely to contribute to global reduction in greenhouse gas emissions and sustainable food security. This paper attempt to explain the role of renewable energy sources in agricultural sector as a means of enhancing sustainable food security in the country and presents the existing technologies, policies  and emerging opportunities in renewable energy application in the agricultural sector. Keyword: Available incentive, Energy policy, Renewable energy, Sustainable food security

DEVELOPMENT OF A MANUALLY OPERATED CASSAVA HARVESTER USING HYDRAULIC MEDIUM

Cassava harvesting in Nigeria is still a major challenge to many small scale farmers who utilize basic tools and implements in its cultivation. Manual cassava harvesting is difficult and full of drudgery especially during the dry seasons when the soil moisture content is low. The mechanized alternatives are way beyond the reach of resource poor farmers. This research study developed a low cost manually powered harvesting device using a hydraulic ram and plunger system. The major components of the harvester include the base frame, the support stand, lifting arm, lifting medium and the clamp. Some of the design considerations include ease of reproducibility and ability to lift the cassava with minimal damage. The hydraulic power source capable of lifting 5ton of weight was adopted with a human effort of 50N (5 kg). Preliminary evaluation of the device on 20 stands of randomly selected mature cassava stands at 63% soil moisture content recorded a minimum time of 13 seconds and a maximum time of 35 seconds respectively while there was no damage recorded on the tubers and stem girth during the harvsesting procedure as the gradually applied load enusred minimal disturbance was casued to the soil&nbsp

SARA Separation and Determination of Concentration Levels of Some Heavy Metals in Organic Fractions of Nigerian Crude Oil

Nigerian Crude oil samples were obtained from Nigerian Petroleum Development Company (NPDC). The samples were subjected to column chromatography.  Sequential leaching method was used to separate the crude oil into four distinct fractions based on leaching of crude oil with different organic solvents and mixtures. Saturated fraction was extracted with hexane- cyclohexane (1:1v/v), aromatic fraction was extracted with hexane- toluene (7:3v/v), while resin was extracted with tetrachloromethane-trichloromethane (7:3v/v), and asphaltene was extracted with acetonitrile-methanol (1:1v/v). The fractions were digested using sulphuric acid, nitric acid and hydrochloric acid method followed by the detection of metals in the samples using AAS analysis. The elements analyzed were Pb, Cu, Cr, Fe and Ni. The result shows that Fe had the highest concentration while Ni had the least concentration. The concentration (ppm) levels of these elements in the crude oil fraction analyzed range from 0.1307 – 0.4107 for Pb, 0.1796 – 1.1250 for Cu, 2.7420 – 10.1903 for Cr, 11.2962 – 21.8084 for Fe, and 0.0464 – 0.5876 for Ni. It was obvious from this study and previous ones that Nigerian crude oil fractions have low metal content. However, despite their low concentrations they can still be detrimental to the refinery operations and the immediate environment, and therefore, should be removed before refining. Keywords: Atomic Absorption Spectroscopy, Aromatic, Asphaltenes, Risens, Saturates, Heavy Metal

Extraction and Formulation of Perfume from Locally Available Lemon Grass Leaves

The availability of wild plants and their use as economically efficient sources of food for man and animals is obvious. In most parts of Nigeria, plant materials whose edible use is not established are regarded as waste materials. Available materials like lemon grass leaves that contain  essential oils can be utilized in the production of perfumes that can mask body odours. Lemon grass extracts obtained using soxhlet extraction andsolvent extraction (maceration) were utilized in the formulation of perfume using methanol and ethanol as solvent media. An oil yield of 4.5% and 3.8% were obtained for solvent extraction and soxhlet extraction methods respectively. Physicochemical properties of the two formulations revealed that the essential oil has saponification value of 21.04mgKOH/g and the densities of the two formulations in methanol and ethanol were 0.768gcm-3 and 0.82gcm-3 at 60oc while the boiling point for both formulations was 85o. The essential oil can be profitably used for cosmetic grade and perfume formulations.Keywords: Essential oil, Extraction, Perfume, Physicochemical Parameter