105 research outputs found
Self-Efficacy and Use of Electronic Information as Predictors of Academic Performance
Abstract
Students’ ability to find and retrieve information effectively is a transferable skill useful for their future life as well as enabling the positive and successful use of the electronic resources while at school. It is a known fact in this digital era that any student at the higher level who intends to better achieve and go further in academics should have the ability to explore the digital environment. Students are increasingly expected to use electronic information resources while at the university. Research was undertaken to determine the level of influence of self-efficacy and the use of electronic information resources on students’ academic performance. This study examined self-efficacy and the use of electronic information as predictors of academic performance. Its participants were comprised of 700 students (undergraduate and postgraduate) randomly drawn from seven departments in the faculty of education, University of Ibadan, Nigeria. Data on the study was collected through the Morgan-Jinks (1999) academic self-efficacy scale and the use of the electronic information scale (UEIS) with r = 0.75. Three research questions were raised to guide the study.
The results indicate that self-efficacy and the use of electronic information jointly predict and contribute to academic performance; that respondents with high self-efficacy make better use of electronic information and have better academic performance; that a correlation exists among self-efficacy, use of electronic information and academic performance; and that the use of electronic information influenced respondents\u27 performance in General Education subjects more than other subjects. Finally, the results reveal that the Internet is the electronic information source students access for information most often. Implications of these results and recommendations are discussed
Synthesis, characterization and crystal structures of two new phenolic mannich bases
Two new Mannich bases, 5-methyl-2-((4-(pyridin-2-yl)piperazin-1-yl)methyl)phenol (1) and 5-methyl-2-((4-(4-nitrophenyl)piperazin-1-yl)methyl)phenol (2), were prepared and characterized structurally with elemental analysis, IR, UV and NMR spectroscopic techniques as well as single crystal X-ray diffraction. Compound I crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 6.6726(2) Å, b = 17.0542(6) Å, c = 13.3222(4) Å, β = 100.832(1)°, V = 1489.00 (8) Å3, Z = 4, R1 = 0.0408, wR2 = 0.1143. Compound II crystallizes in the monoclinic space P21 with unit cell dimensions a = 5.9519(2) Å, b = 17.3315(8) Å, c = 15.7237(7) Å, β = 90.348(2)°, V = 1621.95(12) Å3, Z = 4, R1 = 0.0353, wR2 = 0.0965. Both compounds have their structures stabilized by hydrogen bonding and π∙∙∙π interactions. KEY WORDS: Mannich base, Piperazine, X-ray diffraction, Hydrogen bonds Bull. Chem. Soc. Ethiop. 2019, 33(2), 341-348.DOI: https://dx.doi.org/10.4314/bcse.v33i2.1
Factors Influencing Compliance with The Utilization of Effective Malaria Treatment and Preventive Measures in Wulu, South Sudan
BACKGROUND: High incidence of malaria disease in South Sudan may be largely due to poor/non-compliance with effective treatment and preventive measures. This study examined factors limiting/enhancing compliance with the utilization of known and effective malaria treatment and preventive measures in Wulu, South Sudan.METHODS: A case-control study involving 396 respondents was conducted. Participants were interviewed using a semi-structured questionnaire to elicit information regarding socio-demographics and factors influencing compliance with using available treatment and preventive measures for malaria.RESULTS: Respondents diagnosed with malaria reported lack of insecticide treated nets (51.5%) and forgetfulness (16.6%) as reasons for not using insecticide treated nets. About 26% of them lacked the knowledge of insecticide treated net’s usefulness, while 57.5% of them did not consider it necessary to have door/window barriers. About 44% of all respondents forgot to take prescribed drugs at the right time while 14.5% of them did not complete drug prescriptions because they felt relief of symptoms. There were significant associations between identified factors of compliance to treatment/preventive measures and occurrence of malaria (all at p < 0.001). Having insecticide treated nets (OR: 5.78; CI: 3.46-9.00), awareness of its benefits (OR: 8.76; CI: 3.02-25.37), being taught on its use (OR: 3.35; CI: 2.17-5.18) and understanding of its use (OR: 3.80; CI: 2.01-7.20) were significantly associated with year-round utilization of insecticide treated nets.CONCLUSION: Poor access to and knowledge of malaria treatment, control and preventive measures are leading barriers to their effective utilization in Wulu
Hydrogen peroxide and lime based oxidative pretreatment of wood waste to enhance enzymatic hydrolysis for a biorefinery: Process parameters optimization using response surface methodology
Response surface methodology (RSM) was adopted for the optimization of process variables in the alkaline
peroxide oxidation (APO) pretreatment of Vitellaria paradoxa sawdust based on central composite
design (CCD) experiments. A 23 five level CCD with central and axial points was used to develop a statistical
model for the optimization of process variables. Maximum response for the pretreatment was
obtained when applying the optimum values for temperature (150 �C), time (45 min), and 1% (v/v)
H2O2. At the optimum conditions, up to 70% of the initial hemicellulose was removed in treatments,
which also caused some delignification (up to 11% of the initial lignin was removed), whereas cellulose
was almost quantitatively retained in the solid phase. Alkaline peroxide assisted wet air oxidation (APAWAO)
pretreatment at the optimum conditions resulted in enrichment up to 60% cellulose content along
with solubilization of 80% hemicellulose and 17% of lignin initially present in the raw sawdust. Reducing
sugars yield after 72 h enzymatic hydrolysis of pretreated biomass at optimized APO conditions was
177.89 mg equivalent glucose g�1 dry biomass. Addition of 10 bar air pressure at the optimized pretreatment
conditions increased the sugars yield to 263.49 mg equivalent glucose g�1 dry biomass
African Star Apples Whole Seed Activated Carbon Powder as a Bioadsorbent of Crystal Violet Dye Removal from Aqueous Solution
Investigation shows that African star apple (ASA) whole seed has the potential to eliminate
crystal violet (CV) dye from aqueous solutions. Batch adsorption studies were performed to
show some parameters, which include temperature, amount of adsorbent, pH, dye concentration
and dosage with respect to contact time. The characterization was experimented on the adsorbent
with respect to a scanning electron microscope (SEM) and Fourier transform infrared (FT-IR).
Langmuir, Freundlich, Temkin, Flory-Huggins model and Dubinin-Radushkevich (D-R)
isotherms were analysed using an acidic solution of pH 3.0. Langmuir and D-R models gave
better fit than others. Thermodynamic variables such as entropy (Δ S ads), Gibbs free energy (Δ
G ads) and enthalpy (Δ H ads) suggest that adsorption is spontaneous, making the process
endothermic in nature. The kinetics model also describes the adsorption of the dye on the
adsorbent by pseudo-first order, Elovich and pseudo-second order equation. Attainment of
equilibrium was achieved in 5 h for the amount of dye adsorbed at pH of 8. Column adsorption
was made for bulk removal of dye using eluting NaCl solution, thereby recovering 94% of the
dye
Prevalence of comorbidities in women with and without breast cancer in Soweto South Africa: Results from the SABC study
Background. Comorbidities occurring concurrently in breast cancer patients can be burdensome, as they may negatively influence time and stage of presentation.Objectives. To describe the comorbid health conditions among South African (SA) black women with and without breast cancer and to determine factors associated with advanced-stage presentation of breast cancer.Methods. A population-based case-control study on breast cancer was conducted in black women in Soweto, SA, the SABC (South Africa Breast Cancer) study. Lifestyle information and blood samples were collected from 399 women with histologically confirmed new cases of invasive primary breast cancer, recruited prior to any therapy, and 399 age- and neighbourhood-matched controls without breast cancer. We compared self-reported metabolic diseases, depression, anthropometric measurements, blood pressure, HIV status and point-of-care lipid and glucose levels between patients with breast cancer and the control group.Results. In the whole population, the mean (standard deviation) age was 54.6 (12.9) years, the majority (81.2%) of the participants were overweight or obese, 85.3% had abdominal adiposity, 61.3% were hypertensive, 47.1% had impaired fasting plasma glucose, 8.4% had elevated total cholesterol, 74.8% had low high-density lipoprotein and 10.9% were assessed to be depressed. Ninety-one percent of the whole cohort had at least one metabolic disease. In the breast cancer group, 72.2% had one or more metabolic diseases only (HIV-negative and no evidence of depression), compared with 64.7% of the control group. From a multivariate logistic regression adjusted model, higher household socioeconomic status conferred a 19% reduction in the odds of having advanced-stage breast cancer at diagnosis, while hypertension, dyslipidaemia and HIV were not significantly associated with stage at breast cancer diagnosis in the adjusted model.Conclusions. A large proportion of women experience several comorbidities, highlighting the need to address the chronic non-communicable disease epidemic in SA and to co-ordinate multidisciplinary primary-, secondary- and tertiary-level care in the country’s complex healthcare system for better outcome.Â
Inhibitive Corrosion Performance of the Eco‐Friendly Aloe Vera in Acidic Media of Mild and Stainless Steels
The inhibitive behaviour of aloe vera as an eco‐friendly inhibitor was studied in the corrosion of mild and
stainless steel in 0.5 M H2SO4 medium. The varied aloe vera inhibitor concentrations were studied using
weight loss (gravimetric) and linear polarization methods. The methods showed that the inhibition
efficiency increased with an increase in the concentration of the inhibitor (up to 10 vol/vol%) for both
the mild and stainless steels. Stainless steel was found to exhibit a lower corrosion rate compared to
mild steel. The results showed that Langmuir adsorption isotherm was obeyed by the inhibition of mild
and stainless steel using aloe vera in 0.5 M H2SO4 with the values of the regression coefficients near
unity. The negative values of ΔGads show the spontaneous adsorption of inhibitor on the mild and
stainless steel surfaces and a physisorption adsorption mechanism of the aloe vera inhibitor since the
values of ΔGads obtained are more than − 20 kJ/mol, that is, aloe vera is an efficient corrosion inhibitor
with mixed‐type inhibition property
Optimization of pretreatment conditions using full factorial design and enzymatic convertibility of shea tree sawdust
In this study alkaline wet air oxidation (WAO), alkaline peroxide assisted wet air oxidation
(APAWAO), and enzymatic hydrolysis methods were evaluated for conversion of wood
residue (sawdust) to reducing sugars. Cellulose content, hemicellulose solubilization, and
lignin removal forWAOpretreatment conditions were optimized by statistical analysis using
a 23-full factorial design with reaction temperature, air pressure, and reaction time as the
process parameters. An optimum WAO condition of 170 �C, 1.0 MPa, 10 min was predicted
and experimentally validated to give 518 g kg-1 cellulose content, 580 g kg-1 hemicellulose
solubilization, and 171 g kg-1 lignin removal in the solid fraction. About 7 g L-1 reducing sugars
was detected in the pretreated liquid fraction. Presoaking the dry raw biomass for 24 h in
H2O2 followed by wet air oxidation (APAWAO) at the optimized conditions resulted in
enrichment up to 683 g kg-1 cellulose content in the solid fraction along with solubilization of
789 g kg-1 hemicellulose and 280 g kg-1 lignin removal. The yield of reducing sugars from WAO
optimized conditions by two enzyme preparations (cellulase and b-glucosidase) was
131mgg-1 of dry substrate, while the APAWAO yielded 274mgg-1. Pretreatments used in this
study showed to have a disrupting effect on the lignocellulosic biomass, making the treated
materials accessible for enzymatic hydrolysis. The combination of presoaking inH2O2 before
WAO pretreatment and enzymatic hydrolysis was found to give the highest sugar yield
Evaluation of Methods for the Analysis of Untreated and Processed Lignocellulosic Biomasses
The overall efficiency of the transformation of lignocellulosic materials to usable
products as chemicals and fuels must be governed by adequate analysis of products
before and after treatments. Using some promising technologies, lignocelluloses which
are biomasses from marine plant and trees, grains, food and non-food crops, and woodbased
can give products as fuel alcohol and other chemicals. Various methods of
transformation from feedstock to valuable end products are discussed in the scientific
literature. Therefore, yields must justify methods used for biomass transformations. As
a result, adequate compositional analysis of these processing stages is needed. In this
chapter, standard common methods such as gravimetric, chromatography,
spectroscopic and their variations for analysis on both untreated and treated
lignocelluloses are highlighted. The ease of the use and challenges with
recommendations to their applicability to quantifying lignocelluloses fractionations for
reproducibility and to be representative are discussed. With biomass technology,
virtually all and even more products that can be produced from fossil energy can also
be produced from biomass energy. Adequate analysis is therefore necessary
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