309 research outputs found
Comparison of some preconcentration methods for certain metal ions in human milk and yogurts
Five samples each of yogurts and human milk were separately collected, deproteinized, pre-concentrated differently with 1% 8-hydroxyquinoline, 1% ammonium pyrrolidine-dithiocarbamate (APDC) and extracted with methyl-isobutylketone (MIBK). Activated carbon powder in HNO3 was also used. The extracts obtained were analyzed using atomic absorption spectrometry for some metal ions. In yogurts, the powdered activated carbon in HNO3 exhibited the highest complexing ability with values of 0.04â0.17, 335â476, 1.52â3.82, 0.08â0.27, 0.09â0.28, 1.31â8.78 and 888â12693 mg/L concentration for Zn2+, Mg2+, Mn2+, Cr3+, Cu2+, Fe3+ and Ca2+, respectively. The concentrations of Zn2+, Mg2+, Mn2+, Cr3+, Cu2+, Fe3+ and Ca2+ ions were determined to be in the range of 0.02â0.03, 1.10â9.47, 0.05â0.11, 0.02â3.08, 0.01â0.87, 0.47â18.08
Hydrocarbon Play Assessment of âOswilâ Field,Onshore Niger Delta Region
Hydrocarbon play assessment of any field involves the evaluation of the production capacity of hydrocarbon reservoir unit in the field. This involves detail study of the reservoir petrophysical properties and geological interpretation of structures suitable for hydrocarbon accumulation in the field as observed from seismic reflection images. This study details the assessment of hydrocarbon play in OSWIL field onshore in Niger Delta, with the intent of appraising its productivity using a combination of seismic, well logs,petrophysical parameters and volumetric estimation using proven techniques which involves an integrated methodology. Two reservoir windows âR1â and âR2â were defined from five wells OSWIL-02, 04, 06, 07 and 12.The top and base of each reservoir window was delineated from the wells.Structural interpretation for inline 6975 revealed two horizons (X and Y) and eight faults labelled (F1, F2, F6, F8, F10, F16, F17 and F18). Five faults (F1, F6, F10, F17 and F18) were identified as synthetic faults and dip basin wards while three faults (F2, F8 and F16) were identified as antithetic faults and dips landwards. Time-depth structural map at top of reservoirs R1 and R2 revealed structural highs and closures. These observations are characteristics of growth structures (faults) which depicts the tectonic style of the Niger Delta. Results of petrophysical evaluation for reservoirs âR1â and âR2â across the five wells were analysed. For reservoir âR1â effective porosity values of 27%, 26%, 23%, 20% and 22% were obtained for wells OSWIL-04, 12, 07, 06 and 02 respectively with an average of 23.6%, while for reservoir âR2â effective porosity values of 26%, 22%, 21%, 24% and 23% for wells OSWIL-04, 12, 07, 06 and 02 were obtained respectively with an average of 23.2%. This porosity values correspond with the already established porosity range of 28-32% within the Agbada formation of the Niger Delta. Permeability index of the order (K > 100mD) were obtained for both reservoirs across the five wells and is rated very good. Hydrocarbon saturation (Shc) across the five wells averages at 61.6% for reservoir âR1â and 67.4% for reservoir âR2â. Result of petrophysical model for porosity, permeability and water saturation reveal that the reservoir system in R1 and R2 is fault assisted and fluid flow within both reservoirs is aided by presence of effective porosity and faulting. Volumetric estimation for both reservoirs showed that reservoir R1 contains an estimate of 455 Ă 106 STB of hydrocarbon in place, while reservoir R2 contains an estimate of 683 Ă106 STB of hydrocarbon in place. These findings impact positively on hydrocarbon production in the field and affirm that the two reservoirs R1 and R2 are highly prospective
Characteristics of Al-Alloy/Seashell (SESB) Composites in Acidic and Alkaline Environments
The corrosion behaviour of Al-alloy/Seashell (SeSh) composites in the acidic and alkaline environment was investigated in this study. Fifteen Aluminum alloy composites samples were produced using stir casting technology by varying the amount of reinforcement (1.5, 3.0, 4.5, 6.0, 7.5 wt%) and particle size (100, 150, 200 ”m) of milled SeSh in the Aluminium alloy matrix. The corrosion rate was determined using a weight loss technique after 18 days of immersion at an interval of 72 hours. It was observed that 6.0 wt% of the 100 ”m reinforced Aluminium alloy had the best corrosion resistance in acidic and alkaline environments. In general, the reinforced Al-alloy had better corrosion resistance when compared with the unreinforced samples. Analyses of the results show that aluminum alloy seashell composites exhibited better resistance to corrosion in the alkaline environment than the acidic environment
Design and Construction of a Low-Cost-High-Accessibility 3D Printing Machine for Producing Plastic Components
The additive manufacturing process creates objects directly by stacking layers of material on each other until the required product is obtained. The application of additive manufacturing technology for teaching and research purposes is still limited and unpopular in developing countries, due to costs and lack of accessibility. In this study, an extruding-based 3D printing additive manufacturing technology was employed to design and construct a low-cost-high-accessibility 3D printing machine to manufacture plastic objects. The machine was designed using SolidWorks 2020 version with a 10 Ă 10 Ă 10 cm3 build volume. The fabrication was carried out using locally available materials, such as PVC pipes for the frame, plywood for the bed, and Zinc Oxide plaster for the bed surface. Repetier firmware was the operating environment for devices running on the computer operating system. Cura was used as the slicing software. The fabricated machine was tested, and the printer produced 3D components with desired structural dimensions. The fabricated 3D printer was used to manufacture some plastic objects using PLA filament. The recommended distance between the nozzle tip and the bed is 0.1 mm. The constructed 3D printer is affordable and accessible, especially in developing nations where 3D printing applications are limited and unpopular
Evaluation of Infiltration Rate of Landmark University Soils, Omu-Aran, Nigeria
The processing of adequate information of characteristics of soils is essential for designing quality
soil management and construction practices on agricultural and urban lands. Little is known about
the infiltration capacity of soils in institutions of higher learning, this study therefore evaluated the
infiltration capacity of soils in the Landmark University, Omu-Aran. The double ring infiltrometer
with an inner ring of 30 cm and a 50 cm diameter outer ring with a height of 30 cm above the ground
was used to test infiltration rates at two sites, namely the University of Omu-Aran's orchard area
(OA) and the new college building area (NCBA). Six points labelled (A, B, C, D, E and F) were
identified at 10 m grid intervals at which infiltration rates were determined using a 30 cm inner ring
double ring infiltrometer and a 30 cm height outer ring. Results of soil analysis suggests sand dirty
and silt texture and bulk density and particle density varied from 2.54â3.03 g/cm3 and 1.31â
1.52 g/cm3 respectively. The infiltration rates ranged between 0.007 to 0.011 cm/sec with a mean of
0.009cm/sec in orchard area (OA) and 0.011 to 0.035 cm/sec with a mean value of 0.021 cm/sec in
NCBA indicating a significant difference at both locations. The infiltration rate of soils at the OA is
very low compare to that of NCBA therefore the OA is more prone to flooding. Effective drainage
control system is recommended along the orchard area to prevent flooding
Activity or connectivity? A randomized controlled feasibility study evaluating neurofeedback training in Huntington's disease
Non-invasive methods, such as neurofeedback training, could support cognitive symptom management in Huntingtonâs disease by targeting brain regions whose function is impaired. The aim of our single-blind, sham-controlled study was to collect rigorous evidence regarding the feasibility of neurofeedback training in Huntingtonâs disease by examining two different methods, activity and connectivity real-time functional MRI neurofeedback training. Thirty-two Huntingtonâs disease gene-carriers completed 16 runs of neurofeedback training, using an optimized real-time functional MRI protocol. Participants were randomized into four groups, two treatment groups, one receiving neurofeedback derived from the activity of the supplementary motor area, and another receiving neurofeedback based on the correlation of supplementary motor area and left striatum activity (connectivity neurofeedback training), and two sham control groups, matched to each of the treatment groups. We examined differences between the groups during neurofeedback training sessions and after training at follow-up sessions. Transfer of training was measured by measuring the participantsâ ability to upregulate neurofeedback training target levels without feedback (near transfer), as well as by examining change in objective, a priori defined, behavioural measures of cognitive and psychomotor function (far transfer) before and at 2âmonths after training. We found that the treatment group had significantly higher neurofeedback training target levels during the training sessions compared to the control group. However, we did not find robust evidence of better transfer in the treatment group compared to controls, or a difference between the two neurofeedback training methods. We also did not find evidence in support of a relationship between change in cognitive and psychomotor function and learning success. We conclude that although there is evidence that neurofeedback training can be used to guide participants to regulate the activity and connectivity of specific regions in the brain, evidence regarding transfer of learning and clinical benefit was not robust
Activity or Connectivity? Evaluating neurofeedback training in Huntington's disease
Non-invasive methods, such as neurofeedback training (NFT), could support cognitive symptom management in Huntingtonâs disease (HD) by targeting brain regions whose function is impaired. The aim of our single-blind, sham-controlled study was to collect rigorous evidence regarding the feasibility of NFT in HD by examining two different methods, activity and connectivity real-time fMRI NFT. Thirty-two HD gene-carriers completed 16 runs of NFT training, using an optimized real-time fMRI protocol. Participants were randomized into four groups, two treatment groups, one receiving neurofeedback derived from the activity of the Supplementary Motor Area (SMA), and another receiving neurofeedback based on the correlation of SMA and left striatum activity (connectivity NFT), and two sham control groups, matched to each of the treatment groups. We examined differences between the groups during NFT training sessions and after training at follow-up sessions. Transfer of training was measured by measuring the participantsâ ability to upregulate NFT target levels without feedback (near transfer), as well as by examining change in objective, a-priori defined, behavioural measures of cognitive and psychomotor function (far transfer) before and at 2 months after training. We found that the treatment group had significantly higher NFT target levels during the training sessions compared to the control group. However, we did not find robust evidence of better transfer in the treatment group compared to controls, or a difference between the two NFT methods. We also did not find evidence in support of a relationship between change in cognitive and psychomotor function and NFT learning success. We conclude that although there is evidence that NFT can be used to guide participants to regulate the activity and connectivity of specific regions in the brain, evidence regarding transfer of learning and clinical benefit was not robust. Although the intervention is non-invasive, given the costs and absence of reliable evidence of clinical benefit, we cannot recommend real-time fMRI NFT as a potential intervention in HD
Analysis of potentially toxic elements from selected mechanical workshops using the geoâaccumulation index and principal component analysis in OmuâAran Community, Nigeria
Bioaccumulation of potentially toxic eleïżœments in soil threatens public health and the ecosystem.
This study aims to assess the concentration of potentially
toxic elements (chromium (Cr), lead (Pb), iron (Fe),
arsenic (As), and cadmium (Cd)) in selected automobile
workshop premises in Omu-Aran, Nigeria. Forty-eight
samples were collected at a depth (15 cm) in six locations,
including a control point. Acid digestion was carried out
to prepare the soil samples before assessing their concenïżœtration via an atomic absorption spectrophotometer. Geoïżœaccumulation index (Igeo) was used to classify the level of
contamination. Statistical analysis, which includes princiïżœpal component analysis (PCA) and Pearsonâs correlation,
was also determined. The difference in concentration was
determined using ANOVA. In the study area, the lowïżœest observed concentration values for Cr, Pb, Fe, As, and
Cd, which are 0.246±0.002 mg/kg, 0.178±0.001 mg/
kg, 90.715±0.038 mg/kg, 0.012±0.004 mg/kg, and
0.078±0.004 mg/kg, respectively, are relatively higher
than observed for the control. The observed potentially
toxic elements fall within three Igeo based on Mullerâs
interpretation; heavily to extremely contaminated (Cd),
moderately to heavily contaminated (Pb, Cr, and As), and
uncontaminated to moderately contaminated (Fe). PCA
shows that two principal components (PC) account for up
to 91.052% of the original mean dataset variability. PC1
explains 67.723% of the total variance associated with
Cd, Cr, Fe, Pb, and As, indicating anthropogenic is the
primary source of these potentially toxic elements. The
PC2 accounted for 23.329%, with Pb and As significant
contributors. Cadmium contamination of soil was the
most influential, with an Igeo value ranging from 4 to 5.
Residents in the polluted region face considerable health
risks from potentially toxic elements.
Keywords Heavy metals · Automobile mechanical
workshops · Geo-accumulation index · Principal
component analysi
Nigeria Root Vegetables: Production, Utilization, Breeding, Biotechnology and Constraints
This chapter describes the various facets, from agronomy to marketing, of Nigerian root vegetables including garlic, onion, turmeric, ginger and carrot being the worldâs most significant and vital root vegetables which have high culinary and medicinal value. The chapter commences with their origin and history, universal spread, production figures, areas under cultivation and goes on to explain the botany, diversity, conservation, production practices, pests and diseases management, utilization, post-harvest technology and their uses as nutraceuticals. This chapter also presents the socio-economic, market analyses, export potential of these crops in Nigeria. It would be an important reference material for researchers, agricultural and food science students at both undergraduate and postgraduate level and policy makers; and be of great interest to experts and industries involved in root vegetables and spices trade. The in-depth information and knowledge about the genetic conservation, socio-economics, production, pests and diseases management and post-harvest technology of root vegetables in Nigeria provided in this chapter would greatly help in efforts towards improving their production and utilization for enhanced nutrition and healthy living
Extraction and physicochemical characterization of chitin and chitosan isolated from house cricket
Chitin ranks next to cellulose as the most important bio-polysaccharide which can primarily be extracted from crustacean shells. However, the emergence of new areas of the application of chitin and its derivatives are on the increase and there is growing demand for new chitin sources. In this study, therefore, an attempt was made to extract chitin from the house cricket (Brachytrupes portentosus) by a chemical method. The physicochemical properties of chitin and chitosan extracted from crickets were compared with commercial chitin and chitosan extracted from shrimps, in terms of proximate analysis in particular, of their ash and moisture content. Also, infrared spectroscopy, x-ray diffraction (XRD), scanning electron microscopy and elemental analysis were conducted. The chitin and chitosan yield of the house cricket ranges over 4.3%â7.1% and 2.4%â5.8% respectively. Chitin and chitosan from crickets compares favourably with those extracted from shrimps, and were found to exhibit some similarities. The result shows that cricket and shrimp chitin and chitosan have the same degree of acetylation and degree of deacetylation of 108.1% and 80.5% respectively, following Fourier transform infrared spectroscopy. The characteristic XRD strong/sharp peaks of 9.4 and 19.4° for α-chitin are common for both cricket and shrimp chitin. The percentage ash content of chitin and chitosan extracted from B. portentosus is 1%, which is lower than that obtained from shrimp products. Therefore, cricket chitin and chitosan can be said to be of better quality and of purer form than commercially produced chitin and chitosan from shrimp. Based on the quality of the product, chitin and chitosan isolated from B. portentosus can replace commercial chitin and chitosan in terms of utilization and applications. Therefore, B. portentosus is a promising alternative source of chitin and chitosan
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