37 research outputs found
The conventional versus a constructionist Scratch programming and first-year students' achievements in higher education classes: experimental data.
No full textGlobally, learning or teaching the first programming (popularly called CS1) remains a significant educational challenge. Indicators such as CS1 students' engagement, failure and attrition rates, and lack of diversity, continue to show the need for innovating the learning or teaching of novice computer science students. To ease initiating novices to programming, Scratch, a visual programming language, has become a staple of K-12 CS1 classes.
As outcomes of a research project aiming to explore a constructionist Scratch pedagogy with novice CS students in higher education, we present these datasets. In the research lasting two successive academic sessions, we conducted two quasi-experimental studies involving four intact CS1 classes in selected public polytechnic in the north central Nigeria. In each study, we randomly assigned the classes to the experimental and control groups, constituting the constructionist Scratch and the conventional CS1 classes, respectively.
Instruments for collecting data include a student profile questionnaire, a pretest, and posttest. Sequel to ethical clearance and permission from the selected schools, we conducted each study during the first semester of each academic session, in the first seven to eight weeks. During the first to second week, we administered students who consented to take part with the questionnaire and the pretest. Learning or teaching in the two classes lasted six weeks. Then both classes took the posttest. An independent CS educator who is not part of this research marked all the achievement tests, following a rubric prepared by the first author. To strengthen the research design and the possibility of arriving at valid causal evidence, we employed a Coarsened Exact Matching (CEM) algorithm to generate matched samples of experimental and control data, which we used in the analysis.
Data presented here includes the raw, unmatched and matched experimental datasets from both studies. A researcher can make use of the data:
To explore if some background variables not addressed in the original research may moderate CS1 students' achievements. For instance, their prior achievements in mathematics, physics, or English.
To uncover some interesting patterns using machine learning algorithms.
To validate the outcome of the original experiment by using the unmatched, matched or newly generated matched samples.
The authors welcome further research collaborations in using the data or the accompanying research instruments.
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Assessment of atmospheric profile of some heavy metals in barks of Parkia biglobosa (African locust bean) trees
No full textNatural resource exploitation involving the mining of iron-ore from earth's deposits result in the release of aerodynamic size particulate
metals, dusts and other atmospheric pollutants. The atmospherics baseline levels some iron-ore associated heavy metals were assessed
around Itakpe iron-ore deposit, North Central Nigeria, using tree barks of African locust bean (Parkiabiglobosa) as indicator. Tree barks
of P. biglobosa were randomly scaled off dried and digested using standard procedures. The digests were quantified for Cd, Mn, Cr, Ni,
Cu, Zn and Pb in flame of Unicam 969 atomic absorption spectrophotomer. The concentration of Zn, 20.387-52.07 mg/kg was the highest in respect of other metals determined, followed by Mn, 8.74-24.18 mg/kg and then Pb, 2.95-8.66 mg/kg. Cu levels ranged 0.68-3.14 mg/kg, Ni, 0.34-3.12 mg/kg and Cr, 0.34-0.91 mg/kg. Cd concentration was the least; 0.16-0.48 mg/kg in barks of P. biglobosa trees. The overall mean concentrations (mg/kg) were: Zn, 34.21 ± 4.09; Mn, 13.59 ± 2.04; Pb, 25 ± 0.75; Cu, 1.34 ± 0.34; Ni, 1.18 ± 1.05; Cr, 0.55 ± 0.09; and Cd, 0.33 ± 0.06, with availability sequence is in the order Zn > Mn > Pb > Cu > Ni > Cr > Cd. The detected heavy metals levels in the barks of P. biglobosa trees were variable, and may be a function of vegetation proximity/orientation to source points, plant distribution/population density, level of exposure and atmospheric stability, which is dependent on prevailing climatic factors. The evaluated P. biglobosa barks did not contain the heavy metals at concentrations capable of impacting negatively on the plant. Thus, the tree barks concentration of the evaluated metals were within natural concentration levels, and are therefore regarded as not polluted. This implies that atmospheric levels of the aerodynamic particulates heavy metals were low and not hazardous. The detected levels could serve as
baseline concentration for monitoring against potential atmospheric deposit build up of heavy metals when mining becomes fully operationa
Assessment of Use, Reuse, and End-of-Life Disposal and X-Ray Fluorescence Analysis Screening of Waste Mobile Phones in Nigeria
No full textHEAVY METALS POLLUTION AT MUNICIPAL SOLID WASTE DUMPSITES IN KANO AND KADUNA STATES IN NIGERIA
No full textSoil samples collected from two major dumpsites each in Kano and Kaduna states were
investigated for heavy metals pollution. Each of the dumpsite was divided into north, south, east and west. Four
soil samples were collected at a depth of 0-15 cm from each part and pooled to form a composite sample. Soil
samples from reserve areas within the same geographical locations as the dumpsites were collected as control.
Acid-extractable cadmium (Cd), chromium (Cr), nickel (Ni) and lead (Pb) were determined using 2 M nitric acid
solution and atomic absorption spectroscopy. The ranges of Cd, Cr, Ni and Pb levels for all the dumpsites were
0.30–49.8, 5.76–139, 0.39–19.1 and 42.6–9662 mg/kg, respectively. Kano dumpsite 2 was found to pollute most
with Cd, Cr and Pb in 50-100 % soil samples collected having concentrations higher than the threshold limits set
by regulatory body. Paper and food scraps showed higher percentages in both Kano and Kaduna dumpsites. The
soil was high is sand for all the dumpsites implying high leaching potentials of the heavy metals pollutants
Polychlorinated Biphenyls in Brackish Water Fish in the River Niger, Nigeria
No full textBackground. Anthropogenic polychlorinated biphenyls (PCBs) in aquatic environments poses human and ecological health risks in Nigeria.
Objectives. This study determined the concentrations of PCBs in brackish water fish in the River Niger to assess the contamination status of fish consumed by the local population.
Methods. The sampled fish species included Drepane africana, Mochokus niloticus, Chrysichthys nigrodigitatus, Pristipoma jubelini, Vomer septapinis, Pseudotolithus senegalensis, Mugil cephalus, Pseudotolithus elongatus, Sphyraena piscatorum and Lutjanus goreensis, purchased from landing sites. Six fish from each species were sampled, for a total of 60 samples. Twenty-seven (27) PCB congeners, #8, #18 #28, #44, #52, #60, #77, #81, #101, #105, #114, #118, #123, #126, #128, #138, #153, #156, #157, #167, #169, #170, #180, #185, #189, #195, and #206 were screened in the fish samples using standard methods. The PCBs were identified and quantified using gas chromatography (GC) (Hewlett Packard GC 5890 series 11 with electron capture detector). Confirmation was performed using Shimadzu GCMS QP2010.
Results. The sum of the National Oceanic and Atmospheric Administration Agency (ΣNOAA) PCBs occurred at the highest concentration of 1830.0±484.0 μg/kg detected in Vomer septapinis, and the lowest in Pseudotolithus senegalensis, with a mean concentration of 795±169.3 μg/kg. The concentration of dioxin-like (DL) PCBs was highest in Pristipoma jubelini (992.0±88.6 μg/kg) and lowest (285.6±81.5 μg/kg) in Drepane africana. The highest mean concentration (418.±177.6 μg/kg) of International Council for the Exploration of the Seas-7 (ICES-7) PCBs was observed in Vomer septapinis. The heavier ICES-7 congeners PCB-138, PCB-153, and PCB-180 occurred at higher concentrations compared to the lighter molecular weight ICES-7: PCB-28, PCB-52, and PCB-101. The European Union (EU) marker PCB limit of 335 μg/kg was exceeded in all the brackish water fishes with the exception of Mochokus niloticus, Pristipoma jubelini and Pseudotolithus senegalensis.
Discussion. The total level of PCBs in the brackish fish samples was relatively high at >1000 μg/kg (above the World Health Organization (WHO) and Food and Agriculture Organization of the United Nations (FAO) guideline of 1000 μg/kg fresh weight). The EU guideline value for fish (220 μg/kg fresh weight) was exceeded in about 80% of the brackish fish samples studied.
Conclusions. Consumption of fish from the River Niger may expose humans to polychlorinated biphenyls. In addition, since contamination of the fish samples is an indication of river contamination, river water quality is of great concern and there is a need for additional PCB data on water quality to be distributed to the community, followed by mitigation measures.
Competing interests. The authors declare no competing financial interests
Vulnerability assessment of groundwater pollution in the vicinity of an active dumpsite (Olusosun), Lagos, Nigeria
No full textThe deleterious impacts of dumpsite activities and the associated risk on both the
environment and human is consequential, hence this study assessed
groundwater vulnerability to pollution from dumpsite using a modified DRASTIC
model. Six hydrogeological factors: D- Depth to water, R- Net Recharge, AAquifer
media, L- Distance of well to dumpsite, T- Topography, and C- Clay
content were used in the modification (DRALTC) based on peculiarity of the
study area. Cluster analysis of groundwater data and Water Quality Index (WQI)
were also evaluated. The groundwater vulnerability index was characterized by
two zones; forty five percent (45%) moderate and fifty five percent (55%) high
zones. The dendogram showed three clusters of chemical dissimilarities. The
WQI showed values between 61.8 and 205, indicating good, poor and very poor
class of water. The analysis of the groundwater samples showed nitrate
concentration ranging from 7.60 to 35.6 mg/L and from 8.56 to 32.4 mg/L in dry
and rainy seasons, respectively. The DRALTC model was validated using nitrate
concentration. Though, there appeared relative groundwater protection from
contamination, there is still need for measures to mitigate further contamination
and associated risk in the moderate vulnerability zones. DRALTC model is proved
a good tool in groundwater management
Polychlorinated Biphenyls in Brackish Water Fish in the River Niger, Nigeria
No full textBackground. Anthropogenic polychlorinated biphenyls (PCBs) in aquatic environments poses human and ecological health risks in Nigeria.
Objectives . This study determined the concentrations of PCBs in brackish water fish in the River Niger to assess the contamination status of fish consumed by the local population.
Methods . The sampled fish species included Drepane africana, Mochokus niloticus, Chrysichthys nigrodigitatus, Pristipoma jubelini, Vomer septapinis, Pseudotolithus senegalensis, Mugil cephalus, Pseudotolithus elongatus, Sphyraena piscatorum and Lutjanus goreensis, purchased from landing sites. Six fish from each species were sampled, for a total of 60 samples. Twenty-seven (27) PCB congeners, #8, #18 #28, #44, #52, #60, #77, #81, #101, #105, #114, #118, #123, #126, #128, #138, #153, #156, #157, #167, #169, #170, #180, #185, #189, #195, and #206 were screened in the fish samples using standard methods. The PCBs were identified and quantified using gas chromatography (GC) (Hewlett Packard GC 5890 series 11 with electron capture detector). Confirmation was performed using Shimadzu GCMS QP2010.
Results. The sum of the National Oceanic and Atmospheric Administration Agency (ΣNOAA) PCBs occurred at the highest concentration of 1830.0±484.0 μg/kg detected in Vomer septapinis, and the lowest in Pseudotolithus senegalensis, with a mean concentration of 795±169.3 μg/kg. The concentration of dioxin-like (DL) PCBs was highest in Pristipoma jubelini (992.0±88.6 μg/kg) and lowest (285.6±81.5 μg/kg) in Drepane africana. The highest mean concentration (418.±177.6 μg/kg) of International Council for the Exploration of the Seas-7 (ICES-7) PCBs was observed in Vomer septapinis. The heavier ICES-7 congeners PCB-138, PCB-153, and PCB-180 occurred at higher concentrations compared to the lighter molecular weight ICES-7: PCB-28, PCB-52, and PCB-101. The European Union (EU) marker PCB limit of 335 μg/kg was exceeded in all the brackish water fishes with the exception of Mochokus niloticus, Pristipoma jubelini and Pseudotolithus senegalensis.
Discussion . The total level of PCBs in the brackish fish samples was relatively high at >1000 μg/kg (above the World Health Organization (WHO) and Food and Agriculture Organization of the United Nations (FAO) guideline of 1000 μg/kg fresh weight). The EU guideline value for fish (220 μg/kg fresh weight) was exceeded in about 80% of the brackish fish samples studied.
Conclusions. Consumption of fish from the River Niger may expose humans to polychlorinated biphenyls. In addition, since contamination of the fish samples is an indication of river contamination, river water quality is of great concern and there is a need for additional PCB data on water quality to be distributed to the community, followed by mitigation measures.
Competing interests. The authors declare no competing financial interests.</jats:p
Assessment of water and sediment around a lead-acid battery plant dumpsites in South-Western Nigeria
No full textIn a quick assessment carried out around dumpsites of a battery manufacturing plant, heavy metals content of sediment, surface water and ground water samples from seven ponds, three streams and a well were assessed using Atomic Absorption Spectrophotometer (AAS). Some physicochemical parameters of the samples were also investigated. Metal concentration in pond and stream sediment samples ranged from 25.71-75,843 μg/gPb, 0.74-4.13 μg/gCd, 32.35-385.31 μg/gCu, 3.17-28.5 μg/gNi, 558.25-908.42 μg/gFe and 10.01-53.59 μg/gZn and these metal concentrations exceeded allowable guidelines for sediment by USEPA. For water samples in general, concentration of metals ranged as Pb(0.001-5.69 mg/L), Cd(0.0006-0.0699 mg/L), Cu(0.001-0.09 mg/L), Ni(0.001-0.38 mg/L), Fe(0.0399-17.099 mg/L) and Zn(0.001-0.14891 mg/L). Physicochemical parameters in water were pH (4.54-7.59), Temperature (25-28 OC), DO (2.49-6.45 mg/L), TS (296-35,100 mg/L), TSS (2.0-281 mg/L), TDS (290-34,800 mg/L), Cl- (12.2-52.5 mg/L), NO3- (3.2-800 mg/L), PO43- (0.14-1.58 mg/L) and SO42- (76.0-5,300 mg/L). Results obtained for TSS, TDS, NO3-, SO42-, Pb, Cd and Fe in water, especially in ponds at Ile-Igbon and Ni in Aweere Stream, exceeded limits set by standard organisations as well as results from similar work
Initial Inventory of Plastics Imports in Nigeria as a Basis for More Sustainable Management Policies
No full textBackground. Plastic is a waste stream with recycling and recovery potential. However, the recycling rates for plastic in African countries are low. Furthermore, use and production of virgin plastics are increasing. Therefore, a high proportion of plastic waste is being disposed of in landfills and dumpsites. Plastic serves as fuel for open burning at landfills/dumpsites with associated releases and constitutes a large fraction of marine litter, making it a major and growing global pollution concern.
Objectives. This study aims to develop an initial inventory of plastics in Nigeria towards the development of an effective plastics management frame.
Methods. A search was conducted of the recent literature and the United Nations (UN) Comtrade database using harmonized system (HS) codes for import data of various polymer categories and major product categories containing plastic. Algebraic expressions were developed for calculation of the share of plastic in these products.
Results. Approximately 14,200,000 tons of plastics in primary form were imported into Nigeria between 1996–2014. Approximately 3,420,000 tons total plastic were imported in the form of products and approximately 5,545,700 tons were imported as product components. Approximately 194,000 tons of plastic toys were imported over a six-year period.
Discussion. The total amount of plastics imported in primary form and as products equals 17,620,000 tons. The total volume of imported plastic, newly produced plastic and plastic components going into the technosphere was 23,400,000 tons. The huge amount of plastic and other polymers entering the technosphere in Nigeria has important implications for marine litter, pollution, waste management and resource recovery.
Conclusions. A huge volume of plastics has entered the Nigerian technosphere, with less than 12% of the resulting waste entering the recycling stream. There is a need for sustainable management of this crucial waste and resource category. Potential mitigating strategies include waste plastic reuse, recycling, waste conversion to energy, and appropriate plastic control policy frameworks.
Competing Interests. The authors declare no competing financial interests
