1,720,960 research outputs found
Investigation of ground water quality during the dry season in Rivers State, Nigeria: A case study of Port Harcourt Metropolis
No full textThis research is to investigate the quality of ground water in boreholes and hand-dug wells during the dry season in six locations in Port Harcourt metropolis of Rivers State. The locations are Rumuola, D-line and Trans-Amadi, which use borehole while Elechi Beach, Gbundu and Ozubuko still use hand-dug wells.The parameters analysed were iron, chloride, hardness, and pH. Others were total dissolved solids (TDS), ammonia (free and saline), and E-coli. Results indicated that for iron, all except Ozubuko with a value of 0.32mg/l satisfied WHO’s standard. It is not sufficient, however, to reject water containing higher iron content unless a more suitable supply is available. For parameters such as chloride and hardness, the samples from all the locations are within WHO’s limit. This is also true for TDS, while for pH, the water samples from all the locations were acidic, falling short of the standard (6.5 – 8.5) specified by WHO although samples from Rumuola with the highest value of 6.66 fall within the WHO range and hence acceptable. Ammonia levels in the water samples from all the locations were within the recommended value by WHO, with the highest value (5.01) coming from Trans-Amadi, which indicates the highest level of biological reductions in this water. Finally and of greater significance too, is the fact that no E-coli was found in all the samples except that from Gbundu waterside with a level of 3 x 103 as against zero recommended by WHO. This therefore makes the hand-dug well water from Gbundu warterside unsuitable for human consumption
Enhancing bioremediation efficiency of acidic wetlands contaminated with crude oil.
Get PDFBortone, Imma - Associate Supervisor
Coulon, Frederic - Associate SupervisorCrude oil exploration and exploitation has significantly impacted the Niger Delta,
Nigeria wetlands and its ecosystems. Studies suggest that acidification is
ongoing with several acid forming and acid tolerant microbes identified in the
Niger Delta wetlands. The efficient remediation of the crude oil contaminants in
the acidified wetlands is the only alternative left to the Niger Delta for effective
ecological restoration of the environment. In this research, different combinations
of bioremediation strategies were investigated to enhance the remediation of
simulated crude oil contaminated acidic wetlands similar to the Nigeria Niger
Delta wetlands contamination conditions. A series of mesocosm experiments
subjected to wetland condition and a combination of treatments were evaluated
as follows: for biostimulation experiment, Food waste anaerobic digestate
(FWAD), and Tween 80 surfactant were individually added to the mesocosms at
10%, 20% and 30% w/w respectively with soil in the mesocosm experiments. For
bioaugmentation experiments, mesocosms were enriched with Pseudomonas
aeruginosa, Bacillus subtilis, or microbes indigenous to the crude oil spiked soil.
Sequel to the results of these experiments, an optimised combination of FWAD
(30% w/w) plus Tween 80 (30% w/w), Tween 80 (30% w/w) plus indigenous
microbes, and digestate (30% w/w) plus Tween 80 (30% w/w) plus indigenous
microbes were investigated. For each set of the experiments, pristine soil,
acidified soil, and crude oil spiked acidified soil were maintained as controls. Total
petroleum hydrocarbon (TPH) contents, soil basal respiration, and soil microbial
communities’ dynamics were measured over 112 days of the experiments. For
the biostimulation experiment, the FWAD and Tween 80 each at 30% (w/w)
resulted in the highest petroleum hydrocarbons degradation (> 87% removal in
49 days). Augmentation with indigenous microbes enhanced the extent of
degradation of the petroleum hydrocarbons (up to 80% in 49 days). For the
optimised combined strategies, digestate (30% w/w) plus Tween 80 (30% w/w)
plus indigenous microbes resulted in degradation of the hydrocarbons by > 98%.
The correlation between basal respiration, microbial community and
hydrocarbons showed that the more the biogenic CO₂ produced by the relevant
microbial community, the faster the rate of the hydrocarbons degradation. Gram
positive bacteria were the dominant microbial group in the FWAD, Tween 80
surfactant, indigenous microbes, and combined digestate (30% w/w) plus Tween
80 (30% w/w) plus indigenous microbe mesocosms. This research has
demonstrated that acidified wetlands contaminated by petroleum hydrocarbons
can be effectively remediated using low carbon biomaterials and indigenous
microbial consortia. This conclusion was further confirmed by the more than 90%
maize germination and undetectable bioavailable hydrocarbons recorded at the
end of the experiment in these mesocosms. Potential exists for further studies in
low carbon remediation of weathered hydrocarbons contaminants in various
types of wetlands and sediments using FWAD, Tween 80 surfactant, and
indigenous microbes.PhD in Energy and Powe
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Production of biodiesel from TGX-1778 soybeans (glycine max) by sodium hydroxide-catalyzed transesterification
No full textThis study investigated the potential of a Nigerian-grown soyabean (TGX-1778) to produce biodiesel.The Soybeans at room temperature, were dehulled, ground to a powdery form, and the oil extracted bySoxhlet extraction method using n-Hexane. 50 ml of the Soybean oil extract and 0.5 g of NaOH werecharged into three different reactors labeled A, B, and C, and transesterified in turn with 50, 100, and 150ml of methanol respectively. Results showed that transesterification with 50, 100, and 150ml of methanolproduced biodiesel of densities 0.79, 0.80, and 0.77g/ml respectively, while the corresponding kinematicviscosities at 400C were 4.4, 4.6 and 4.1mm2/s. Other parameters of the biodiesel were refractive index,which ranged from 1.33 to 1.34, pH from 8.5 to 9.6, cloud point (<-320C), pour point (-520C) and flashpoint (1500C). Comparison with the American Society for Testing and Materials (ASTM) D6571 standardindicated that the densities were outside the specified range, while kinematic viscosities were within theacceptable limit. Furthermore, the flash point of the biodiesel produced was higher that the specifiedminimum level. It was also observed that increasing the methanol quantity from 50 to 150ml, resulted inan increase in biodiesel produced. On the whole, therefore, the oil from the locally grown soybean has agreat potential for biodiesel production
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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