Open Access Method Articles

Modeling Analysis of Stirred Tank Reactors

Charles Arienrhi Ikutegbe, O. E. Longe, M. O. Alege, M. O. Oduola, A. R. Adetunji

Current Journal of Applied Science and Technology, Page 191-199
DOI: 10.9734/BJAST/2015/16685

Continuously Stirred Tank Reactor (CSTR) was modeled and the reactor performance analyzed with a view to coming up with an essential parametric quantity useful for assessing control at the steady-state design stage. The steady-state design of CSTR and its implementation, using Matrix Laboratory (MATLAB®) program for hypothetical reaction case and the commercial software Aspen Plus® for a real chemical case was performed. The approach adopted considered two separate first-order irreversible exothermic reaction processes, implemented in MATLAB® and Aspen Plus® software respectively and a target conversion and reactor stability ratio (RSR) determined. Results from this study revealed that at varied temperatures (320-360K) under steady-state design, a suitable target conversion of 95% and RSR values less than 0.50 present minimal control problems with irreversible exothermic reactions for both hypothetical and real chemical systems. Conversely, reactor design for low conversion and maximum temperatures can present control problems with exothermic reactions due to larger reactor size and low heat transfer area. The key to improved reactor performance with minimal control problems, is designing at a reasonable low RSR value and providing excess heat transfer area so that disturbances can be properly handled.

Open Access Short Research Article

A Method for Seeking Range of Missing Plane Based on Law of Energy Conservation

Tian-Quan Yun

Current Journal of Applied Science and Technology, Page 206-211
DOI: 10.9734/BJAST/2015/16660

A method for seeking range of a missing plane based on Law of energy conservation is suggested. The method starts with the final information of the location(s) of the plane A(x,y,z) provided by satellites. A flying path with most far from an origin in same time interval [0,T] is proved. Suppose that the flight flies in non-powered state since A(x,y,z). By the Law of energy conservation, the problems corresponding to two ranges of velocity are reduced to Riccati equation and Volterra equation respectively. The exact solutions of these equations are found, and the seeking range is calculated. Finally, the relative motion in longitude direction due to self-rotation of earth is added to the calculated range. A simple calculation is given for reference.

Open Access Original Research Article

Theoretical Study of Cluster Ions Existing in Vapours over Cesium Bromide and Iodide

Stanley F. Mwanga, Tatiana P. Pogrebnaya, Alexander M. Pogrebnoi

Current Journal of Applied Science and Technology, Page 108-130
DOI: 10.9734/BJAST/2015/17612

The properties of ions Cs2X+, Cs3X2+, CsX2, and Cs2X3(X = Br or I) have been studied using the density functional theory and Möller–Plesset perturbation theory of the 2nd and 4th order. For all species the equilibrium geometrical configurations and vibration frequencies were determined. Different isomers of pentaatomic ions were found to exist: the linear (D∞h), V-shaped (C2v), kite-shaped (C2v) and bipyramidal (D3h). The relative abundances of isomers were calculated for temperatures between 700 K and 1600 K. It was found that at about 800 K, the amount of different isomers was comparable for Cs3Br2+, Cs3I2+ and Cs2I3 ions, while for Cs2Br3 the linear isomer was proved to be predominant. The enthalpies of dissociation reactions with elimination of CsX molecules and the enthalpies of formation of ions were determined.

Open Access Original Research Article

The Pathology of Nematode Infection in Parachanna obscura (Pisces: Channidae Gunther, 1886) of the Cross River System, Nigeria

D. Ama-Abasi, E. M. Oden

Current Journal of Applied Science and Technology, Page 131-136
DOI: 10.9734/BJAST/2015/14674

Study was conducted on the pathology of nematode infection in Parachanna obscura of the lower Cross River system, Nigeria. The objective was to find out specific pathological damages in Parachanna obscura caused by nematode infection. A total of five hundred and seventeen specimens of Parachanna obscura were sampled from artisanal fishers from January 2007 to August 2008. The infected fish were processed through the standard parasitological and histopathological procedures. Damages caused by nematode included black spots on the muscle fillet, muscle disintegration, gastrointestinal occlusion, exfoliation of intestinal mucosa, haemorrhage and distortion of the blood tissue. Infected fish had slightly lower health performance as revealed by the low condition factor compared to the non-infected. A one-way ANOVA however showed that there was no significant difference in the health index (P > .05) between the infected and the non-infected. There are potentials that the culture of nematode infected Parachanna obscura will lead to economic loss to aqua culturists, in terms of poor fillet quality and reduction in growth due to blood loss and poor nutritional activities. If P. obscura is to be used in aquaculture, anti-helminthes treatment must be applied before stocking. Further research would be needed in insitu detection of nematodes. This will boost food security and a turnaround in the economic fortune of the people of the lower Cross River basin.

Open Access Original Research Article

The N: P: Si Stoichiometry and Relative Abundance of Diatoms in Ganga River

Jitendra Pandey, Amita Yadav, Rachna Singh

Current Journal of Applied Science and Technology, Page 137-147
DOI: 10.9734/BJAST/2015/17223

In order to assess the changing pattern of N: P: Si stoichiometry and associated shift in the abundance of diatoms, we analysed DO, BOD, NO3-, PO43-, DOC and DSi in a 37 km long stretch of Ganga River. The N: P stoichiometry declined (from 13.6 to 5.3) at downstream sites receiving urban influence. Similar was the trend for Si: P ratio indicating relatively higher input of P in comparison to N and Si. The chlorophyll a biomass and gross primary productivity (GPP) showed positive correlation with BSi (P < 0.001) and P enrichment at downstream favoured the abundance of Amphipleura, Aulacoseira, Craticula, Cymbella, Fallacia and Fragilaria. Since the excessive growth of exploitative species may replace less adapted diatoms, the skewed elemental stoichiometry in the study river may alter the diatom assemblages with increased abundance of P favoured species at urban sites. The study has relevance addressing diatom community level cause-effect relationships and provides important cues for designing action plan towards restoration of this major river system.

Open Access Original Research Article

Comparative Analysis of Cement and Lateralite on the Engineering Properties of Niger Delta Soils for Pavement Construction

F. M. Alayaki, A. Al-Tabbaa, E. A. Meshida, M. J. Ayotamuno

Current Journal of Applied Science and Technology, Page 148-158
DOI: 10.9734/BJAST/2015/18256

This study investigated the effect of cement and lateralite in improving some engineering properties of Niger Delta soils, classified as clayey soil, silty/clayey sand, and fine sand. Cement had very good effect in reducing the plasticity of the clayey soil and the silty/clayey sand but increased the plasticity of the fine sand, and all the samples had increased soaked CBR and UCS at 28 days especially with 6% and 8% cement contents. 14% lateralite content had the best effect on the silty/clayey sand in reducing the plasticity and increasing both the CBR and UCS. However, no positive effect on the plasticity indices was noticed for the clayey soil and the fine sand, but appreciable increases in their unsoaked and soaked CBR and UCS at 28 days curing. The applications of cement (6% and 8%) and 14% lateralite would make the stabilized soils applicable as sub-base and base materials.

Open Access Original Research Article

Optical Studies of Cotton Fabrics Dyed with a Natural Dye

E. S. El-Amoudy, A. A. El-Ebissy

Current Journal of Applied Science and Technology, Page 159-171
DOI: 10.9734/BJAST/2015/17227

In the present work, cotton fabrics were dying with a natural colorant from Calligonum comosum plant under different conditions to determine the ultraviolet protection factor (UPF) values and the effect of light exposure and laundering on the sun blocking properties of these dyed cotton fabrics. Three different dyeing conditions, such as: different bath temperatures, different pH values of the dye bath and different dyeing times, were applying during dyeing the cotton fabrics. The role of these dyeing conditions on the UPF was examining via color strength analyses as well as their effects on the reflectance spectra were investigating using spectrophotometer tool, CIE tristimulus values and the color parameters. The dye-ability strength and fastness to light and wash of these cotton fabrics were also carrying out spectrophotometrically. The results showed that dyeing cotton fabrics with Calligonum comosum dramatically increased their protective abilities and were considering as an effective protection against ultraviolet rays. Moreover, the data obtained indicated that the optical properties are very different because of changing dye bath conditions. In addition, it was hoping that data obtained in the present study would be useful for dermatologists advising patients regarding the UV-protective properties of clothing made from natural fibers and dyed with natural colorants.

Open Access Original Research Article

The Focus on the Computation of Induced Magnetic Field in Magnetoplasmadynamic Thrusters

A. M. Tahsini

Current Journal of Applied Science and Technology, Page 172-181
DOI: 10.9734/BJAST/2015/17531

Physical analysis of the magnetoplasmadynamic thrusters, especially ones with self induced magnetic field, demonstrates the interaction of applied electric and induced magnetic field to affect the flow field and accelerate it to reach the higher specific impulses. Such interaction besides changing the fluid state to the plasma, acts as momentum and energy source terms which should be predicted carefully. The former method which has been frequently used to compute the induced magnetic field is analyzed here and is shown that despite of its mathematical validity of the governing equation, it is disable to compute the induced magnetic field due to the problems in boundary condition. Therefore the accurate method is suggested here which shows much better abilities to study the induced magnetic field and can be utilized in performance analysis and numerical simulation of MPDTs.

Open Access Original Research Article

Determinants of Constraints to Information Sources Utilization among Maize Farmers in Edo State, Nigeria

D. U. Okoedo-Okojie

Current Journal of Applied Science and Technology, Page 182-190
DOI: 10.9734/BJAST/2015/17688

This study identified determinants of constraints to information sources utilization among maize farmers in Edo state, Nigeria. Data were collected from 150 randomly selected maize farmers with the aid of structured questionnaire validated by expert judgment, and analyzed using frequency, percentage, mean and Chi-square for hypothesis testing. Results showed that majority (66.0%) (59.3%) (53.3%) and (50.7%) of the respondents had farm size of < 1 hectare, were married and males and household heads, respectively. Most preferred information sources were radio (M = 2.69) fellow farmer (M = 2.60), posters and bill board (M = 2.59), and books and leaflets (M = 2.58). Most serious constraints faced in the use of information sources were poor radio and television signals (M = 3.42), inadequate rural electrification and constant power interruption (M = 3.23), agriculture information and radio aired at odd hours (M = 3.15), lack of time to listen to agriculture information (M = 3.10), agriculture information is not broadcast on radio and television in my area (M = 2.99). There was a significant relationship between access to credit (R2 = 7.416), farm ownership (R2 = 12.497) sex (X2 = 13.759) of respondents and constraints encountered in information sources utilization at 0.05 level of significance. It was recommended that the Ministry of Agriculture should study time for broadcasting agriculture information in understandable language to attract maize farmers to listen, Radio and television signals needs to reach rural areas to improve audience level of farmers for increased proven technologies information utilization.

Open Access Original Research Article

Gross Alpha and Beta Activity Concentrations in Cassava Tubers (Manihot esculenta) from Old Coal Mining Area in Enugu, South Eastern Nigeria

Chijioke M. Amakom, Nnamdi N. Jibiri, Chikwendu E. Orji

Current Journal of Applied Science and Technology, Page 200-205
DOI: 10.9734/BJAST/2015/15268

Cassava crops and its food constitute more than 65% of dietary components for the population from the south-eastern Nigeria. Any contamination of this food crop in the environment by radioactive sources through human activities such as mining will affect large portion of the population. Following coal mining activities that took place in Enugu and the likelihood of potential increase in radiation dose burden to the population, the gross alpha and gross beta activity concentration in cassava tuber samples cultivated within the old coal mine area was investigated. The gross alpha activity concentration in the mined area ranged from (BDL) to 670 Bq/kg and for gross beta it was from BDL to 1220 Bq/kg. In the coal processing and distribution area, gross alpha ranged from (BDL) to 590 Bq/kg while for the gross beta it ranged from 70 to 770 Bq/kg. In the control area the gross alpha activity concentration was found to range from 20 to 690 Bq/kg and 370 to1420 Bq/kg for the gross beta. However, as could be seen from the study, the coal mining activities in the area has not affected the concentrations of gross alpha and gross beta radiation in the cassava crops within the areas considered.