Open Access Original Research Article

Comparative Evaluation of Some Nutrient Contents and Antifungal Properties of Ground Musa paradisiaca (Plantain) Peels and Leaves

Anthony Cemaluk C. Egbuonu, Wisdom O. Nneji, Chimnonye A. Ukasoanya

Current Journal of Applied Science and Technology, Page 1-8
DOI: 10.9734/BJAST/2017/28393

Musa paradisiaca (plantain) fruit peels and the plant leaves may have some nutrients and antifungal properties. Thus, the study determined and compared some nutrients (minerals and vitamins) in the ground plantain peels and leaves and the antifungal property of the aqueous and ethanol extracts (at concentration of 100 mg/ml) of the ground plantain peels and leaves, using standard methods. In either sample, vitamin A was not detected. The difference (±5.28 mg/100 g) in the highest of the detected vitamins, vitamin C in the samples, was statistically significant (p<0.05) whereas the difference (±0.01 mg/100 g) in the least detected vitamins, vitamin B2, was not significant (p>0.05). Out of the determined minerals (mg/100 g), the highest concentration was potassium (40.00 ± 0.08) in the plantain leaves followed by phosphorous (36.00 ± 1.65) in the plantain peels while the least was magnesium (1.80 ± 0.05) in the leaves followed by iron (5.60 ± 0.06) in the peels. The ethanol and aqueous extracts of the peels and leaves showed activity (inhibition zone diameter measured in millimeter, mm) against Candida albicans, however, the activity of the ethanol extract of the leaves (15.67±0.58) was higher (p<0.05) than that of the ethanol extract of the peels and the aqueous extract of the peels and leaves. The difference in activity against C. albicans between the samples extracts in terms of either the same or the different extracting solvent was significant (p<0.05) but the overall difference between the samples compared to the extracting solvents (±0.67) was the same hence non-significant (p>0.05). A similar trend was recorded for the activity of the ethanol and aqueous extracts of the peels and leaves against P. notatum. Thus, the plantain peels and leaves could be alternative source for vitamin C. The extracts (aqueous and ethanol) had activity against C. albicans and P. notatumhence may be useful in managing such pathogen-induced ailments. Overall negligible difference in activity against either C. albicans or P. notatum in terms of samples and the extracting solvents was suggested and this may be an underlying useful trend for comparing the overall antimicrobial activity of different samples and solvents, hence warrants a follow up.


Open Access Original Research Article

Rate Decline-based Models for Gas Reservoir Performance Prediction in Niger Delta Region

Anietie N. Okon, Daniel T. Olagunju, Julius U. Akpabio

Current Journal of Applied Science and Technology, Page 1-14
DOI: 10.9734/BJAST/2017/31184

This work considers the Decline Curve Analysis (DCA) approach as a quick tool to estimate the gas reservoir performance of field “ABC” in the Niger Delta region. The conventional Arps’ models: Exponential, Harmonic and Hyperbolic, alongside with the Reciprocal and Quadratic models were used. Production data: gas production rate (qt) and gas cumulative production (GP)  were obtained from 13 wells in the field “ABC”. Multivariate analyses were performed with the mentioned models to establish the decline constant (Di) and decline exponent (b); for hyperbolic model, of the field “ABC” in the Niger Delta region. A decline constant of 0.000064day-1 was obtained from all the models with exception of Reciprocal model with 0.00053day-1 for the gas field. Also, the decline exponent (b) obtained for Hyperbolic model was 0.9999. The statistical analysis: absolute error, standard deviation and coefficient of determination, of the fitted models used to ascertain the extent of their predicted values differ from the field test data results in Arps’ models: Exponential - 0.1150, 0.02666 and 0.9981; Harmonic - 0.11547, 0.02665 and 0.9982 and Hyperbolic - 0.11547, 0.02665 and 0.9982, respectively. Furthermore, Reciprocal and Quadratic models generated an absolute error, standard deviation and coefficient of determination of 0.09726, 0.026745 and 0.9911, and 0.0097, 0.000008 and 0.9998, respectively. Thus, the results indicate that, modern rate decline models for reservoir performance analysis can compete with the well-known Arps’ model(s). Therefore, the fitted Quadratic-based model can be used as a quick tool to analyze the reservoir performance of the gas field “ABC” in the Niger Delta region.


Open Access Original Research Article

Choosing the Optimal Segmentation Level for POS Tagging of the Quranic Arabic

Fadl Mutaher Ba-Alwi, Mohammed Albared, Tareq Al-Moslmi

Current Journal of Applied Science and Technology, Page 1-10
DOI: 10.9734/BJAST/2017/29754

As a morphologically rich language, Arabic poses special challenges to Part-of-Speech (POS) tagging. Words in Arabic texts often contain several segments; each has its own POS category. The choice of the segmentation level or the input unit, word-based or morpheme-based, is a major issue in designing any Arabic natural language processing system. In word-based approaches, words are used the atomic units of the language. In this case, composite POS tags are assigned to words. Therefore, large amounts of training data are required in order to ensure statistical significance. They suffer from the problems of data sparseness and unknown words. In case of morpheme-based approaches, morpheme components of words are used as the atomic units.  This, however, results in high level of ambiguity rate and also small size of context for resolving such ambiguity because the span of the n-gram might be limited to a single word. This paper compares and contrasts the morpheme-based and word-based statistical POS tagging strategies. This paper evaluates  the  tagging  performance  of  three  statistical  models,  namely,  the  Arabic  HMM  POS  tagger  with  the  prefix  guessing  models, the Arabic HMM  POS tagger  with  the  linear  interpolation guessing models and the TnT tagger, given training data from both morpheme-based and word-based tokenization levels. It also studies the influence of each choice on the tagging performance of the Arabic POS tagging models, in terms of the tagging accuracy and the time complexity. In addition, this paper also evaluates the tagging performance of several stochastic models, given training data from both segmentation levels. Results show that the morpheme-based POS tagging strategy is more adequate for the purpose of training statistical POS tagging models as it provides a better overall tagging accuracy and a much faster training and tagging time.


Open Access Original Research Article

Response Time Improvement on One Time Password (OTP) Technique to Prevent Replay Attack in a Radius Environment

Yusuf Abdullahi, Muhammad Bashir Muazu, Adewale Emmanuel Adedokun

Current Journal of Applied Science and Technology, Page 1-37
DOI: 10.9734/BJAST/2017/29503

This research is aimed at the modification of the Remote Access Dial in User Server (RADIUS) protocol with the one-time password (OTP) technique for the authentication environment with a captive portal to prevent replay attacks. One of the important network security measures on a campus network is the use of authentication for identification of legitimate users and one of the most widely used solution in network authentication is the RADIUS protocol. However, there are potential security vulnerabilities in the RADIUS network especially for networks using captive portal, such as the replay attack. The Ahmadu Bello University (ABU) network is simulated using the GNS3 software on a virtualized environment using Virtualbox, which comprises of the core, distribution and access levels of the network and network devices (routers and switches). An OTP generator was developed using PhP programming language for the three variants of the OTP: Time One Time Password (TOTP), Challenge Response One Time Password (CROTP) and Hash One Time Password (HOTP). Before improvement on the OTP technique using a PhP developed script, the result obtained shows the average response time for TOTP, CROTP and HOTP as 2.5s, 5.2s and 5.7s respectively, this result showed no improvement in the TOTP, CROPT and HOTP response time respectively when compared with the recommended response time of a RADIUS server in a captive portal environment which is 1000 ms [1]. After improving the OTP technique by integrating all the variants of OTP with the RADIUS server on a single server using the simulated ABU campus network using GNS3, the result shows a significant improvement over the above results. The results obtained shows the average response time for TOTP, CROTP and HOTP as 1.3s, 2s and 1.9s. The validation, based on the developed and simulated configuration was carried out using live servers, routers and switches and the results showed improvement over the above results the average response time for TOTP, CROTP and HOTP were obtained as 0.4s, 0.9s and 0.9s respectively. This shows significant improvement in the TOTP, CROPT and HOTP respectively. The result shows the average response time is less than the recommended 1000ms for RADIUS server response time in a captive portal environment.


Open Access Original Research Article

Geological, Geophysical and Seismological Investigations for Siting of Seismic Stations in Minna and Abakaliki, Nigeria for Data Reliability

U. K. Afegbua, T. A. Yakubu, M. S. Tsalha, C. O. Ologun, T. S. Oluwadare, D. Duncan, J. Uwazuruonye J. Uwazuruonye, G. Okwunwa, P. Ekweuzoh, M. Enang, O. A. Agoro

Current Journal of Applied Science and Technology, Page 1-22
DOI: 10.9734/BJAST/2017/31078

The goal of this study is to adopt international standard criteria to carefully select sites to host seismic stations in Minna and Abakaliki, Nigeria, that can give reliable seismic data with high network detectability, monitor local seismicity and record local events with improved accuracy. By this, mistakes made during the construction of existing stations in Nigeria would be avoided systematically. To achieve these therefore, detailed field assessments were carried out to select most suitable site amongst the four potentials sites earlier proposed to host the sensitive seismic equipment for each area. These steps were later followed with detailed geological, geophysical and seismological investigations to ascertain the rock types at the sites; determine the depth of the bedrock where the sensor would be placed; and evaluate the signal to noise ratios and sources of possible noise to the pre-selected sites. Results from the various investigations have helped a team of seismologists, geologists, geophysicists and GIS experts drawn from the Centre for Geodesy and Geodynamics (CGG), Federal Ministry of Science and Technology and the National Emergency Management Agency (NEMA), to select most reliable sites for seismic stations in Minna and Abakaliki. As this is the first time these kind of investigations have been undertaken to select a site for seismic equipment in Nigeria, it is expected this study would set standard practices for future site selection for sensitive equipment in Nigeria and in the sub-region.

Open Access Original Research Article

Optimization in the Computation of Dielectric Constant of Methanol Using Debye Relaxation Method

T. J. Ikyumbur, M. Y. Onimisi, S. G. Abdu, E. C. Hemba, Z. J. Kirji

Current Journal of Applied Science and Technology, Page 1-10
DOI: 10.9734/BJAST/2017/31374

The Debye relaxation equation and its derivatives were used to analyze dielectric constant and loss factor of pure methanol in megahertz and gigahertz over the temperature range of 10°C to 50°C. This was done in order to ascertain which of the frequency ranges has the highest dielectric constant and least loss factor. The graphs of dielectric constant and loss factor were plotted against the frequency. The results were also used to plot Cole-Cole diagrams. The results revealed that the dielectric constant of methanol is higher at frequency 0.05 GHz and decrease as both frequency and temperature increases. However, as the frequency increases beyond 1.0 GHz the dielectric constant increase as the temperature increases. The results also showed that methanol actually formed a semi-circle which suggested that the solvent indeed exhibits Debye relaxation model. There were some discrepancies observed in the Cole-Cole plots which may just be attributed to the distribution of the relaxation times in the methanol. The researchers conclude that dielectric constant of methanol is higher in megahertz than those in gigahertz. The loss factor on the other hand was small at lower frequencies but as the frequency increases the loss factor also increases to a maximum value. The loss factor however decreased when the frequency increases after attaining its maximum.

Open Access Original Research Article

Simulation of Steady State Heat Conduction Using an Hybrid Floating Walk and Markov Chain Technique

Ademola A. Dare

Current Journal of Applied Science and Technology, Page 1-10
DOI: 10.9734/BJAST/2017/30224

Markov chain technique had been developed for numerical simulation of steady state heat conduction. However the technique could only be used to handle domain with regular boundaries. An hybrid of floating walk and Markov chain techniques has therefore been developed.

The technique was used to simulate temperature distribution in rectangular and two arbitrary shaped domains with mixed boundary conditions. The results obtained were compared with that obtained using finite difference and as well as using floating walk technique. Results were statistically analysed using ANOVA (α =0.05) and the computer execution for all the three cases considered compared.

The results from the developed hybrid technique were not significantly different from those from finite difference and floating walk techniques. The hybrid technique execution time was longer than that of finite difference technique but shorter than the floating walk technique.

The study established the suitably of the hybrid floating walk markov chain technique for analysis of steady state heat conduction of arbitrary shaped domain.


Open Access Original Research Article

Mammogram Classification Using Discrete Wavelet Transform Features and a Novel Vector Quantization Technique for Breast Cancer Detection

Ahmad M. Sarhan, Radaan A. Al-Dosari

Current Journal of Applied Science and Technology, Page 1-14
DOI: 10.9734/BJAST/2017/30420

In this paper, a digital mammogram classification system is presented. The proposed system uses the Discrete Wavelet Transform (DWT) to obtain   features from the input mammogram image. The proposed system suggests a new algorithm for generating the codebook used by the vector quantization (VQ) algorithm to classify the input mammogram (malignant, benign, or normal). The obtained results on the DDSM database indicate the significant performance and superiority of the proposed method in comparison with the state of the art approaches.  Simulation results show that the proposed system achieves a high accuracy and sensitivity.

Open Access Original Research Article

The Delineation of Potential Groundwater Aquifers within Basement Complex in ABU Zaria, Nigeria

N. Kure, Aboh O. H yacientjh, Jimoh Raimi, Joseph O. Alao, Isaac H. Daniel

Current Journal of Applied Science and Technology, Page 1-9
DOI: 10.9734/BJAST/2017/31343

A geoelectrical survey was carried out in order to evaluate the groundwater potential of ABU Zaria, Nigeria. A total of four Vertical Electrical Soundings (VES) were carried out using Schlumberger electrode configuration with half current electrode spacing of maximum 100 m. The Interpreted data revealed that the study area is underlain by three to four layers. The topsoil thickness and resistivity values vary from 0.4 – 2.0 m and 186 – 833 Ωm respectively. The thickness and resistivity of the weathered basement ranges between 3.0 – 15.2 m and 109 – 360 Ωm respectively. The fresh basement layer which has resistivity values of 1603 – 49788 Ωm is of infinite depth and thickness. The areas with relatively high thickness and low resistivity values of the weathered layer and fractured bedrock have been successfully identified as potential aquifer zone targets for groundwater exploitation.


Open Access Review Article

Recent Advances on Mercury Speciation in Aquatic Ecosystems, Health Effects and Analytical Techniques

Solomon Omwoma, Silah C. Lagat, Joseph O. Lalah, Philip O. Owuor, Karl-Werner Schramm

Current Journal of Applied Science and Technology, Page 1-37
DOI: 10.9734/BJAST/2017/31635

Elemental mercury is not as poisonous as its congeners such as methyl mercury and dimethyl mercury, especially at trace levels. However, understanding the speciation mechanisms of mercury in aquatic ecosystems offers an opportunity to appreciate the dangers emanating from elemental mercury in the environment. Notably, elemental mercury is occasionally used in dental filling therapy which presents it as a non-poisonous element. Recent advances on mechanisms of elemental mercury speciation, health effects of different mercury congeners and analytical techniques of identifying/quantifying them in aquatic ecosystems are outlined. The effects of anthropogenic activities employing the use of elemental mercury such as gold amalgamation are highlighted through a case study. Kenya Gold mines are identified as a potential risk zone amenable to mercury health effects.