105 research outputs found
Experimental Optimization of Lead (II) Bioadsorption from Aqueous Solution onto Banana Stalk using Central Composite Design
This study investigated the effect of operating parameters on the bioadsorption process of Pb(II) from its aqueous solution using three Banana Stalk (BS) bioadsorbents [Raw (RBS), Acid Activated (AABS) and Base Activated (BABS) ]. A five-factor, three-level Central Composite Design (CCD) was applied to determine the effects of independent variables (initial metal concentration, contact time, temperature, adsorbent dosage and solution pH) on percentage Pb(II) removal. Response Surface Methodology (RSM) was employed to optimize the parameters in the experiment. AABS had the highest percentage removal (96.13%) from the preliminary experiment and was then used for the optimisation experiment. Data analysis showed that all the variables significantly affected the percentage Pb(II) removal at p < 0.05. The square of the adjusted coefficient of determination for regression model of percentage Pb(II) removal is 0.9355. Optimum percentage removal of 96.41% was obtained using AABS when the Pb(II) concentration, contact time, temperature, dosage and solution pH were 21.83g/mL, 152.21minutes, 50oC, 0.90g and 8.00, respectively. There absolute error between the experimental and the predicted optimum percentage removal was less than 1%. Keywords: Banana stalk, optimization, bioadsorption, acid, base
Soft Computing Approaches to Stock Forecasting: A Survey
Soft computing techniques has been effectively applied in business, engineering, medical domain to solve problems in the past decade. However, this paper focuses on censoring the application of soft computing techniques for stock market prediction in the last decade (2010 - todate). Over a hundred published articles on stock price prediction were reviewed. The survey is done by grouping these published articles into: the stock market surveyed, input variable choices, summary of modelling technique applied, comparative studies, and summary of performance measures. This survey aptly shows that soft computing techniques are widely used and it has demonstrated widely acceptability to accurately use for predicting stock price and stock index behavior worldwide
Operability of Mobile Agent Applications in a Protected Environment
There is a shift toward increasingly heterogeneous networks in today�s communications environment. Such diversity requires that network operators have greater experience and increased training. Managing these diverse networks especially in institutions requires the collection of large quantities of data from a dependable network that must be analyzed before management of any activity can be comenced. In this research, we have identified the operability of mobile Agents in a protected network environment
OPTIMAL ALLOCATION OF PIPE DIAMETERS IN PIPE NETWORKS USING MODIFIED ASSIGNMENT PROBLEM APPROACH
Water supply to areas of need via pipe network has been a problem since the pipes layout involved may be complex and thereby making the determination of pipe diameters for cost minimization difficult. In this paper, attempt was made on the determination of optimal diameters of pipe that minimizes pipe network cost. The work involves the use of linear programming optimization techniques formulated in a modified assignment problem approach. This was applied to a problem previously worked upon with some other techniques to ascertain the strength of this present approach implemented on MATLAB 6.5 version computing environment. The minimum cost unit of 41900 for eight-pipe, one reservoir and two loop distribution system obtained was the same with that of the “best run” in the previous reported works. Also, 12 functions evaluation in 53 seconds on Pentium 233MHZ processor computer produced this optimal condition as against the 1372 evaluations in 7 minutes on Pentium 100MHZ processor computer for the previous “best run”. These indicate the efficiency and the effectiveness of the studied approach
Surgically treated acromegaly patients have a similar quality of life whether controlled by surgery or requiring additional medical therapy (QuaLAT Study).
Purpose
There is no consensus on quality of life (QOL) in patients with acromegaly requiring medical treatment after surgery compared with those achieving remission by surgery alone.
Methods
QuaLAT is a cross-sectional study comparing QOL in surgery-only treated acromegaly patients versus those requiring medical treatment post-surgery. Patients attending clinics were identified and divided into—Group 1: patients who had surgery only and were in biochemical remission, Group 2: all patients on medical treatment post-surgery, Group 3: patients from Group 2 with biochemical control. Participants were asked to fill three questionnaires; Acromegaly Quality of Life Questionnaire (ACROQOL), 36-Item Short Form Survey (SF36), and Fatigue Severity Scale (FSS).
Results
There were 32 patients in Group 1 and 25 in Group 2. There was no difference in QOL scores between groups 1 and 2, as measured by ACROQOL (mean difference [MD] = − 2.5, 95% CI − 16.6 to 11.6; p = 0.72), SF36v2 [Physical component score (PCS) MD = − 4.9, 95% CI − 10.9 to 1.2; p = 0.12; mental component score MD = − 3.0, 95% CI − 10.5 to 4.4; p = 0.44], or FSS (MD = − 0.004, 95% CI − 1.14 to 1.33; p = 0.1). Comparison between groups 1 and 3 however showed that PCS (and 3 subdomains) was significantly better in group 3 (MD = − 8.3, 95% CI − 14.8 to -1.8; p = 0.01). All three QOL scores were lower when compared with healthy controls.
Conclusions
Medical treatment not only achieves a QOL comparable to surgery, it may also be associated with better QOL in physical subdomains. When compared with healthy controls, QOL remains worse in treated acromegaly patients compared to controls
Measuring the Impact of Fdi on Economic Growth in Nigeria
Abstract: This study investigates the impact of FDI on Nigeria's economic growth process. In an attempt to do this, the paper tests the validity of the modernization or depending hypothesis by employing various econometric tools such as Augmented Dickey Fuller (ADF) and Phillips Perron (PP) tests, Johansen Cointegration test, the Error Correction Mechanism (ECM) and Granger Causality test on time series data from 1970-2008. The results reveal that a long run relationship exists between the variables and a unidirectional causality from FDI to growth was also established. Thus, empirical findings support the modernization hypothesis that FDI is growth promoting in Nigeria
Antimicrobial activities and phytochemical properties of Annona muricata leaf
Annona muricata is a well-known economic and traditional plant of Nigeria. The study investigated the properties of constituents and antimicrobial activities of extracts of the leaf of A. muricata. The extracts were tested against Escherichia coli, Pseudomonas aeuroginosa, Staphylococcus aureus and Candida albicans by the agar well diffusion method at concentration of 20 mg/mL. The methanol (AM2) and ethyl acetate (AM4) extracts were characterized using UV and IR spectroscopy. The morphological structure of the A. muricata leaf was observed at a magnification of 20,000X using SEM and then subjected to EDX analysis. The results of the phytochemical screening revealed the presence of phenolic compounds, flavonoids, tannins, alkaloids, saponins and cardiac glycosides in the extracts. Anthraquinone was found absent. The ethyl acetate extract was found highly active against gram positive bacteria, S. aureus (ZI of 42 mm; AI = 1.31) and ampicillin resistant gram negative P. aeruginosa (ZI of 34 mm; AI = 1.13). The IR spectra of AM2 and AM4 extracts of A. muricata showed peaks at a frequency of 3377 cm-1 to 3440 cm-1 indicating the presence of a phenolic OH stretch. This supports the phenolics detected chemically. The UV spectrum of methanol extract showed peaks that are typical of flavonoids and phenolics. The SEM revealed the sizes of the leaf particles as inhomogeneous. EDX results showed high oxygen concentration of 73.5 % and carbon concentration of 26.5 %.The findings proved the anti-infective potential of Annona muricata leaf and established physico-chemical markers for the active extracts
Comparative Study of Microwave-assisted and Conventional Synthesis of 3-[1-(s-phenylimino) Ethyl]-2H-chromen-2-ones and Selected Hydrazone Derivatives
In this study, 3-acetylcoumarin 1, used as the essential precursor was synthesized by the reaction of salicyaldehyde with ethyl
acetoacetate in the presence of a catalytic amount of piperidine in solvent-free medium. Schiff bases 2-9 were obtained by the
condensation reaction of 3-acetylcoumarin, 1 with various aniline derivatives while reaction of 3-hydrazinoquinoxalin-2-one with
four different 6-susbtituted 3-acetylcoumarins afforded the corresponding hydrazones 10-13. Both Schiff bases and hydrazone
products were synthesized under microwave irradiation method and conventional synthetic strategy for comparative study. The
microwave assisted reaction was remarkably successful and gave both Schiff bases and hydrazones in higher yields at shorter
reaction time compared to conventional heating method. The characterization of the synthesized compounds were structurally
confirmed by analytical data as well as spectroscopic means which involved 1H-and 13C-nmr, ir, UV-visible and mass spectra
The prescribing of generic medicines in Nigeria : knowledge, perceptions and attitudes of physicians
Generic medicines have the same efficacy and safety as originators at lower prices. However, there are concerns with their utilization in Nigeria. Evaluate physicians’ understanding and perception of generics. Questionnaire among physicians working in tertiary healthcare facilities in four geo-political regions of Nigeria. Response was 74.3% (191/257) among mainly males (85.9%). The mean knowledge score regarding generics was 5.3 (maximum of 9) with 36.6%, 36.1% and 27.2% having poor, average and good knowledge respectively. Cross-tabulation showed statistical significance (P = 0.047) with the duration of practice but not with position, subspecialty or sex. The majority did not agree that generic medicines are of lower quality than branded medicines. Therapeutic failure was a major concern in 82.7%, potentially discouraging prescribing of generics. Majority (63.9%) did not support generic substitution by pharmacists. Knowledge gaps were identified especially with the perception of generics. These need to be addressed
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