Agronomic Response of Fluted Pumpkin (Telfairia occidentalis Hook. F.) to Plant Densities and Fertilizer Application in a Tertiary Institution Experimental Farm in Benin City Nigeria

The objectives of this study was to investigate yield, nutrient concentration and uptake of fluted pumpkin (Telfairia occidentalis Hook. F.) in response to plant densities and fertilizer application. Two fluted pumpkin plant densities (10,000 and 20,000 plants ha-1) D1 and D2 were evaluated at three levels of NPK fertilizer (F1, 20 t ha-1 poultry manure, F2, 300 kg ha-1 NPK 15:15:15 and F3, 10 t ha-1 poultry manure + 150 kg ha-1 NPK 15:15:15) using a factorial arrangement in randomized complete block design (RCBD) with three replications. Leaf length, breadth, number of leaves and stem diameter were significantly increased at both plant densities of 10,000 and 20,000 plants ha -1 while herbage yield increased with higher plant density of 20,000 plants ha -1using 300 kg ha-1 inorganic NPK 15:15:15 or a combination of 10 t ha-1 poultry manure + 150 kg ha-1 inorganic NPK 15:15:15. Potassium (K) concentration was significantly (p < 0.05) higher at 10,000 plants ha -1 and Iron (Fe) uptake was higher with combine application of organic and inorganic fertilizer (F3). To maximize good herbage yield of fluted pumpkin, farmers in this locality should adopt plant density of 20,000 plants ha -1using 300 kg ha-1 inorganic NPK 15:15:15 (D2F2) or a combination of 10 t ha-1 poultry manure + 150 kg ha-1 inorganic NPK 15:15:15 (D2F3)

Densification behavior of spark plasma sintered duplex stainless steel reinforced with TiN nanoparticles

Abstract: Duplex stainless steel (SAF 2205) reinforced with titanium nitride (TiN) nanoparticles ranging from 0 to 8 wt% were fabricated in vacuum via spark plasma sintering (SPS) using optimized SPS process parameter of 1150 oC, 10 min and 100 oC/min. The influence of TiN addition on the densification and shrinkage mechanism of the fabricated duplex stainless steel composite were evaluated. The results indicate even dispersion of the TiN nanoparticles in the steel matrix during tubular mixing. The displacement and shrinkage rates showed three densification stages relating to micro-nano particles rearrangement, plastic deformation of the particles and rapid densification of the composite. The steel composite samples displayed relatively high densities in the range of 96-99 % of the calculated theoretical density but were noted to decrease with TiN content

A correlation between nano and micro-hardness properties of TiN nanoparticles strengthened SAF 2205

Abstract : This work studied the correlation between Vickers and nano-hardness of SAF 2205 reinforced with TiN nanoparticles for the convenience of assessing its mechanical properties. Spark plasma sintering was used to fabricate the composites. Micro and nanoindentations were performed to determine micro and nanohardness values of the fabricated composite. Optical microscope was used to assess the microstructure. The microstructure revealed that the TiN dominated the ferrite/ferrite, ferrite/austenite and austenite/austenite grain boundaries. The micro and nanohardness at the TiN dominated grain boundaries were higher compared to the grain hardness. Hardness also increased considerably as the TiN nanoparticles increases. This is also owed to the strengthening effect played by TiN at the grain boundaries by disrupting dislocation motion in the composite. The determined Vickers hardness was plotted as a function of the corresponding nanohardness, a good linear relation was found between Vickers hardness and nanohardness. A linear relationship (HV = 215.15 + 15.03Hnano) was established which indicates that there is no difference in behavior for the Vickers hardness and nano- hardness

Antioxidant and Antimalarial Activities of Methanol Extract of Picralima nitida Root Bark

Ethnomedically, the root, stem bark, seed or leaves of Picralima nitida are relevant in local preparations as antimalaria, antipyretic, antihypertensive and gastrointestinal agents. This study was therefore designed to determine the antimalarial and antioxidant effects of the methanol extract of the root bark of Picralima nitida using standard procedures. The antioxidant activity of the methanol root bark extract was evaluated using 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging method and ferric reducing antioxidant power (FRAP) assay. The antimalarial activity of the methanol root bark extract was investigated using the 4-day suppressive test in mice infected with Plasmodium berghei. The extract showed a concentration-dependent antioxidant activity with 50% inhibitory concentration (IC50) for free radical scavenging activity of 10.19 µg/mL, while the FRAP value was 0.17 ± 0.00 mM FSE/g Extract. The extract demonstrated significant antimalarial activity with 68.33% and 67.27% parasitaemia suppression at doses of 400 mg/kg and 800 mg/kg, respectively. The present study has shown that the root bark extract of P. nitida has antioxidant and antimalarial activities. This study does not only validate the claimed ethnomedicinal use of the plant as antimalaria but also has shown the plant as a potential source of active antimalarial agent

Etnobotânica e medicina popular no tratamento de malária e males associados na comunidade ribeirinha Julião – baixo Rio Negro (Amazônia Central)

RESUMO A utilização de plantas medicinais para o tratamento de doenças tropicais como a malária na Amazônia Central é de suma importância, principalmente em locais onde o sistema único de saúde não se encontra presente como na maioria das comunidades ribeirinhas desta região. Sendo assim, investigar e resgatar o conhecimento popular a respeito de plantas medicinais utilizadas no tratamento de malária e males associados pelos moradores da comunidade Julião situada na Reserva de Desenvolvimento Sustentável do Tupé, Manaus-AM, torna-se importante no registro de como as populações locais se previnem e tratam essa doença tão prevalente e perigosa na região. O trabalho foi conduzido na forma de oficinas participativas, segregadas por gênero e complementadas com entrevistas semiestruturadas aliadas à técnica da turnê-guiada nos quintais e floresta adjacente à comunidade. Foram calculados os índices de diversidade de Shannon-Wiener, equitabilidade e concordância quanto ao uso principal (CUP). A partir da colaboração efetiva de 13 comunitários foram registradas 62 espécies vegetais pertencentes a 53 gêneros e 34 famílias botânicas que resultaram em índice de diversidade (H’) de 1,62 decits e equitabilidade de 0,9. As famílias mais representativas foram: Fabaceae (7 espécies), Asteraceae e Lamiaceae (4 espécies cada) e Solanaceae e Rutaceae (3 espécies cada). Vale destacar que 16 espécies (25,8%) foram citadas para tratamento de malária e males associados pela primeira vez em estudos etnobotânicos realizados na América Latina

NECOP Propagation Experiment: Rain-Rate Distributions Observations and Prediction Model Comparisons

Empirical distribution functions for one-minute average rain-rate values were compiled for three station year of observations at Nigeria environmental and climatic observatory (NECOP) propagation experiment terminal sites. The empirical distribution functions were compared with cumulative distribution functions generated using four different rain-rate distribution models. It is found that although each of the models shows similar qualitative features at lower exceedance of time, the characteristic at higher time percentages shows quantitative difference from the experimental data except the improved version of Moupfouma model. The results further show that the rainfall rate and the microwave propagation characteristics in this region are out of accord with International Telecommunication Union predictions. This information is vital for predicting rain fading cumulative probability distributions over this region

Studies of Super-Refractivity and Ducting of Radiowaves in Nigeria

Studies of tropospheric refraction of long and short wavelength radio signals have been carried out in the coastal and savannah areas of Nigeria using meteorological data collected by radiosondes in Lagos (30 45' E, 60 28' N) and Kano (80 30' E, 120 2'N). Daily mean values of the initial refractivity gradients, dN/dh, were computed for the two zones and the results obtained have been used to classify the refractivity profiles as sub-refractive, normal, super-refractive and ducting. The refraction of radiowaves in the lower atmosphere is considered to be normal whenever the refractivity gradient is —40N/km. Between about — 41N/km and —156.9N/km, the atmosphere is super-refractive and when the refractivity gradients become equal to, or more negative than —157N/km ducting occurs. The modified refractive index was also computed for the two zones. A negative gradient of M is a useful indicator as to the occurrence of ducting. The refractivity values obtained show that the propagation conditions are super-refractive at the coastal region, especially during the rainy season. At Oshodi, the surface layer is super-refractive 75% of the time with 38% probability of occurrence of ducting. The surface layer at Kano, on the other hand, is sub-refractive 88% of the time with the probability of occurrence of ducting being only 3.5%. Nigeria Journal of Pure and Applied Physics VOLUME 1, AUGUST 2000, pp. 5-1

0°C isotherm height distribution for Earth-space communication satellite links in Nigeria

225-234For an optimum performance of Earth-space satellite communication links, a number of meteorological parameters are needed to be considered along the Earth-space path for specific locations and the height of the 0°C isotherm (freezing level height) is among such parameters. Information regarding this parameter is always based on the recommendation of ITU-RP-839 in the form of contour maps. Since the meteorological parameters are location dependent, there is a need for the establishment of these parameters for specific locations. In addition, ITU-R model uses an yearly averaged constant rain height for the attenuation estimation, which may not be appropriate for tropical regions. In the present paper, the 0°C isotherm (ZDI) height has been established using two years of data collected on-board the precipitation radar of the Tropical Rain Measuring Mission (TRMM) satellite. The result shows the seasonal dependence of the 0°C isotherm height. It is observed, among other things, that the height is higher during the wet season as compared to the dry season. Rain induced attenuation at frequencies above 10 GHz is also estimated using the 0°C isotherm height derived for each of the locations over the elevation angle of the NIGCOMSAT-1R in Nigeria