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Search Results: 1 - 10 of 223864 matches for " R. Ogah "
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Evaluating the effect of host plant resistance and planting dates on the incidence of legume pod borer (Maruca vitrata Geyer) on African yam bean in Nigeria.
EO Ogah, FE Ogah
African Crop Science Journal , 2012,
Abstract: Legume pod borer (Maruca vitrata (Geyer)) is one of the major biotic constraints to increasing the productivity of most grain legumes in the tropics. In this study, field experiments were conducted to assess the effect of host plant resistance and planting dates on the incidence of African yam bean pod borer Maruca vitrata (Geyer) in Nigeria. Planting of African yam bean (Sphenostylis stenocarpa) varieties in May led to less infested by M. vitrata and differed significantly (P < 0.05) from those planted in June and July. Of all the varieties assessed, TSs9 was the most resistance and differed significantly (P < 0.05) from the rest of the varieties; while TSs84 was the most susceptible with poorest grain yields. All the varieties when planted in May had less post-flowering insect infestations and produced higher grain yields than those planted later. Flowering and podding formation stages of African yam bean (AYB) planted in July coincided with the peak population densities of M. vitrata, resulting in a significant reduction in yields. The highest grain yields were recorded under a combination of early planting with resistant varieties. Key Words: Maruca vitrata, Sphenostylis stenocarpa, susceptibility
Productivity and Egg Quality Characteristics of Free Range Naked Neck and Normal Feathered Nigerian Indigenous Chickens
A. Yakubu,D.M. Ogah,R.E. Barde
International Journal of Poultry Science , 2008,
Abstract: A study was conducted in Nasarawa State, North Central Nigeria to determine the productivity and egg quality traits of free range naked neck and full-feathered chickens. A total of one hundred and two smallholder farmers were randomly selected. Information was obtained on average eggs per clutch, hatchability and mortality, while hen`s body weight was measured directly on the day of egg collection. One hundred and two freshly laid eggs (51 eggs from each genotype) were used to evaluate external and internal egg qualities. Body weight and average eggs per clutch were significantly (p< 0.05) higher in naked neck genotype compared to the normal feathered birds (1.30 vs. 1.16kg; 11.63 vs. 9.71 respectively). Normal feathered genotype recorded higher mortality (36.85%) than naked neck birds (28.60%). No significant (p> 0.05) difference was found between the two genotypes in hatchability. Mean values for egg weight, egg length, egg width, egg shape index, shell thickness, albumen weight, albumen height, yolk weight, yolk height, yolk width and haugh unit were significantly (p< 0.05) higher in naked neck hens than their normal feathered counterparts. There was no superiority in shell weight and yolk index. The association between egg weight and other egg biometrical traits were found to be positive and significant (r = 0.22-0.79; p< 0.05). Other egg parameters were either positively or inversely correlated with each other. Egg weight was better predicted (R2 = 34.44%) using a combination of egg length and egg width. The estimation of shell weight from egg length, egg width and egg weight gave lower values (R2 = 2.86-3.91%). The incorporation of allometry improved the prediction accuracy of shell thickness, albumen weight and yolk weight from egg weight (R2 = 44.16,43.89 and 49.89%). It is concluded that the introgression of the naked neck gene into poultry could play a pivotal role in the genetic improvement of traditionally managed flocks.
Pulmonary hypertension in Nigeria
Ogah Okechukwu
PVRI Review , 2010,
Abstract:
The Beam-Forming Technique for Enhancement of Noisy Seismic Refraction Data  [PDF]
Arewa James Ogah, Ani Donatus Chinedu
International Journal of Geosciences (IJG) , 2012, DOI: 10.4236/ijg.2012.324087
Abstract: We have described a method of obtaining useful information from noisy seismic refraction data. The simple method, tagged beam-forming technique, is based on the basic time-distance equations of refraction seismology. It involves basically of introducing relative time delays to individual seismic traces of seismic refraction spread to correct for the non-coincidence of the incidence seismic energy at different geophones, and averaging the traces to obtain the beam. The assumption here is that the signal is coherent between the geophones while the noise is random, and for groups of geophones corresponding to the same refraction segments of the travel time curve, this basic assumption is valid. The process of beam forming therefore leads to improvement in signal-to-noise ratio (SNR) and correct determination of the intercept times which are subsequently used to compute other geologic layer parameters. The ability of the applied technique to filter out or minimize random noise has been tested using a modified random number routine. The performance test on computation of geologic layer parameters using very noisy synthetic data reveals that the method is still very reliable even with very poor quality data having SNR as small as 0.05.
Electrical Resistivity Imaging of Suspected Seepage Channels in an Earthen Dam in Zaria, North-Western Nigeria  [PDF]
Ani D. Chinedu, Arewa J. Ogah
Open Journal of Applied Sciences (OJAppS) , 2013, DOI: 10.4236/ojapps.2013.31020
Abstract:

To determine and map the subsurface conditions of a dam, a 2D electrical resistivity tomography study was carried out within the two flanks of Zaria dam at Shika. This was done to ascertain if the variations in the volume of water content in the dam is due to an anomalous seepage beneath the subsurface or seasonal effects. On the basis of the interpretation of the acquired data, various zones of relatively uniform resistivity values were mapped and identified. The first zone is characterized by moderate resistivity values of 150 - 600 ohm-m. It represents unsaturated topsoil with thicknesses varying from 1 - 4.5 m. The second (intermediate depth) resistivity zone, with values ranging from 5 - 100 ohm-m and thickness varying from 3.5 - 10 m, represents a silt clay layer with high moisture content. The third resistivity zone represents fairly weathered granite and is characterized by relatively high resistivity values ranging from 700 - 6000 ohm-m. The available borehole log data correlated well with the pseudo-sections in relation to the obtained resistivity values and depth. Zones of relatively low resistivity within the bedrock are interpreted to represent potential seepage pathways. Hence, this geophysical method can be successfully used to delineate and map these seepage pathways within the subsurface of the earth dam.

Biogas Production from the Co-Digestion of Cornstalks with Cow Dung and Poultry Droppings  [PDF]
I. J. Ona, S. M. Loya, H. O. Agogo, M. S. Iorungwa, R. Ogah
Journal of Agricultural Chemistry and Environment (JACEN) , 2019, DOI: 10.4236/jacen.2019.83012
Abstract: The Anaerobic digestion of Corn Stalk (CS) with Cow Dung (CD) and Poultry Droppings (PD) was investigated. Batch mono-digestion and Co-digestion experiments were performed with initial total solid loading of 37.5%. The main objective of this work was to investigate the biogas yield at different CS to CD ratios and CS to PD ratios. Results show that the highest Cumulative Gas Yield (CGY) of 6833 mL/g of biomass was achieved in 21 days for CS-CD ratio of 2:1. Similarly high CGY of 6107 mL/g, 6100 mL/g and 5333 mL/g were obtained for CS-PD ratio of 2:1, CS-CD ratio of 1:1 and CS-PD ratio of 1:1 respectively. It is concluded that co-digestion of Cow dung or poultry droppings is beneficial for improving bio-digestibility and Biogas yield from corn stalk. The results of this work provide useful information to improve the efficiency of co-digestion of CS with CD and PD under anaerobic conditions.
Assessing the Impact of Varietal Resistance and Planting Dates on the Incidence of African Yam Bean Flower Thrips (Megalurothrips sjostedti, Hochst. Ex. A. Rich) in Nigeria
Emmanuel O. Ogah
Asian Journal of Plant Sciences , 2011,
Abstract: African yam bean (Sphenostylis stenocarpa, Hochst. Ex. A. Rich) is one of the underutilized leguminous crops in the tropics despite its nutritional potentials. One of the major reasons for the gross neglect of this crop in many parts of Africa is its low grain yield when compared to other grain legumes under monocrop. The infestation of the plant by flower thrips Megalurothrips sjostedti has been recorded as the major causes of low yield of the crop. M. sjostedti can cause yield losses of up to 100%. Following its current status as a minor crop, only very few researches have been undertaken in its production especially as it relates to insect control. Hence, in this study we assessed the effect of varietal resistance and three planting dates on the incidence of the thrips and crop yields in Nigeria during 2009/2010 farming seasons. The results indicated that all the varieties planted in May of each season were less infested by M. sjostedti and differed significantly from those planted in June and July of each season. Amongst the varieties assessed, TSs9 was the most resistance and differed significantly from the rest of the varieties. The results of the grain yields showed that all the varieties performed better with higher grain yields when planted in May than those planted later. The flowering and podding formation stages of AYB planted in July coincided with the peak population densities of M. sjostedti resulting in a considerable reduction in grain yields. The highest grain yields were recorded under a combination of early planting with resistant varieties. It could therefore be concluded that planting African yam bean earlier in the season has significant effect on M. sjostedti incidence and grain yield.
Analysis of Morphological Traits of Geographically Separated Population of Indigenous Muscovy Duck (Cairina Moschata)
D.M. Ogah
International Journal of Poultry Science , 2009,
Abstract: Inter and intra specific variation among muscovy duck ecotypes from three agroecological zones of Nigeria were studied The work evaluate the morphological variation of three ecotypes ( rainforest ecotypes, humid or guinea savanna and dry savanna ecotypes) covering southern or coastal region, central and northern part of Nigeria. Twelve morphological traits including weight were considered. Significant (p<0.05) variation exist within and between ecotypes using population coefficient of variation (ANOVA) bill height had the highest coefficient of variation 79.52 while body length recorded the least variation. There are marked differences in body morphology between sexes in all the ecotypes indicating significant sexual dimorphism. Correlation between the traits were low to high. The inter specific variations in bill structure and body morphology are indication of adaptation to the environment and influence of ecological condition
Characterization and Comparison of Rheological Properties of Agro Fiber Filled High-Density Polyethylene Bio-Composites  [PDF]
Anselm O. Ogah, Joseph N. Afiukwa, A. A. Nduji
Open Journal of Polymer Chemistry (OJPChem) , 2014, DOI: 10.4236/ojpchem.2014.41002
Abstract:

The rheological behavior of composites made with high-density polyethylene (HDPE) and different agro fiber by-products such as corncob (CCF), Rice hull (RHF), Flax shives (FSF) and Walnut shell (WSF) flour of 60 - 100 mesh were studied. The experimental results were obtained from samples containing 65 vol.% agro fiber and 3 wt.% lubricant. Particle sizes distribution of the agro fibers was in the range of 0.295 mm to ?0.125 mm. SEM showed evidence of complete matrix/fiber impregnation or wetting. The melt rheological data in terms of complex viscosity (η*), storage modulus (G'), loss modulus (G\"), and loss tangent (tanδ) were evaluated and compared for different samples. Due to higher probability of agglomeration formation in the samples containing 65 vol.% of agro fillers, the storage modulus, loss modulus and complex viscosity of these samples were high. The unique change in all the samples is due to the particle size distribution of the agro fibers. The storage and loss modulus increased with increasing shear rates for all the composites, except for Walnut shell composite which exhibited unusual decrease in storage modulus with increasing shear rate. Damping factor (tanδ) decreased with increasing shear rate for all the composites at 65 vol.% filler load although there were differences among the composites. Maximum torque tended to increase at the 65 vol.% agro fiber load for all composites. Corncob and Walnut shell composites gave higher torque and steady state torque values in comparison with Flax shives and Rice hull composites due to differences in particle sizes distribution of the agro fibers.

Hydrological Modeling of Aquifers and Their Ground Water Potentials: Implications for Water Resources Planning and Management in Parts of Obio/Akpor L.G.A, Rivers State, Nigeria  [PDF]
Vincent Ezikornwor Weli, Jimmy Adegoke, Ogah Celestine Ndidi
Journal of Water Resource and Protection (JWARP) , 2016, DOI: 10.4236/jwarp.2016.83031
Abstract: This study examined the hydrological modeling of aquifers and their ground water potentials for the purposes of water resources planning and management. This was done using the electrical resistivity method employing the schlumberger electrode configuration at randomly selected stations to obtain the thicknesses and resistivities of each layer and depth to the presumably conglomeratic sand stone and its resistivity. Findings showed that the top soil layer resistivity values vary from 59.3 to 248.4 ohm-m and thickness of 0.6 to 3.9 m. The second layer has resistivity values ranging from 45.0 to 743.5 ohm-m and a thickness range of 1.5 to 13.8 m. The wet sand is characterized by resistivity values ranging from 144.8 to 1930.2 ohm-m and a thickness range of 3.8 to 65.8 m. The conglomeratic sand/sand stone has resistivity values ranging from 55.8 to 7719.8 ohm-m. The depth to this bottom layer varies from 6.6 to 89.5 m. Findings indicate that the entire profile is a sedimentary formation represented by lithological units of sand and clayey sand which make for a good groundwater potentials. However, the groundwater potential zones of the study area in terms of transmisivity revealed four distinct classes representing “very good” (Mgbuosimini, Rumuigbo, Okporo, Rumuomasi and Rumuodara), “good” (Alakahia, Rumuodomaya, Oginigba and Rumuola), “moderate” (Aluu, Rumuekeni, Rumuokoro, Rumuobiakani and Rumueme), and “low” (Ogbogoro, Ozuoba, Akpajio, Elelenwo, Eliozu, Rumuepirikon, Rumuokwuta, Rumuebekwe and Rumurolu) groundwater potential in the area. Well logging should therefore be incorporated in borehole development process for safe and sustainable yield of groundwater in Obio/Akpor.
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