Open Access Original Research Article

Contamination Levels of Organochlorine and Organophosphorous Pesticide Residues in Water and Sediment from River Owena, Nigeria

Yetunde A. Adeshina, Akinnawo Solomon, Aiyesanmi F. Ademola

Current Journal of Applied Science and Technology, Page 1-11
DOI: 10.9734/cjast/2019/v34i230119

River Owena functions as the source of water for the Owena dam which supplies drinking water to the communities in the region, the river also plays an important economic role in irrigation and fish farming in the region. But there has been an indiscriminate used of pesticide because residents of the study area are not well orientated concerning the negative impact of pesticide in the environment. Analysis of organochlorine and organophosphorous pesticide residues was carried out in water and sediment from river Owena, the objective of the research is to determine the contamination levels of organochlorine and organophosphorous pesticide in the water and sediment of river Owena. Analysis was carried out using gas chromatography coupled with electron capture detector in order to identify and quantify the concentration of organochlorine and organophosphorous pesticide in the water and sediment samples from river Owena. Analysis revealed the contamination of water and sediment with organophosphorous pesticide residues at different contamination levels in both dry and rainy season, while a low levels of organochlorine pesticide residues only during the dry season. The TOPP for sediment samples ranges from 1.045mg/L during the dry season and 2.279mg/L during the rainy season, while the TOPP for water samples ranges from 7.163mg/L during the dry season to 7.83mg/L during the rainy season. The TOCP values ranges from 1.288mg/L to 0.015mg/L for sediment and water samples respectively during the dry season, while organochlorine pesticides were not detected during the rainy season. The occurrence and seasonal variation of organophosphorous pesticide residues in river Owena can be attributed to the intense agricultural and urban activities in the vicinity of river Owena. 

Open Access Original Research Article

Rapid Tissue Clearing in Pre-warmed Xylene Without Compromising Staining Adequacy and Histoarchitecture

K. C. Onyegbula, O. N. Afahaene, S. T. Awolaja, O. Makinde

Current Journal of Applied Science and Technology, Page 1-7
DOI: 10.9734/cjast/2019/v34i230120

Aims: To determine the adequacy of nucleo-cytoplasmic staining characteristics and preservation of nucleo-cytoplasmic morphology of mouse liver tissue cleared in pre-warmed xylene at predetermined temperatures and durations using haematoxylin and eosin staining procedure.

Study Design: Tissues for clearing were first divided into 3 broad experimental groups (A, B and C) based on pre-determined tissue clearing temperature. Each broad group were further divided into 4 sub-groups (A1 to A4, B1 to B4 and C1 to C4) based on duration of tissue clearing.

Place and Duration of Study: Department of Medical Laboratory Science, Babcock University, Ilishan-Remo, Nigeria and Department of Oral Pathology, College of Medicine, University of Ibadan, Nigeria. January-June, 2015.

Methodology: Tissues assigned to sub-groups A1 to A4 were cleared in pre-warmed xylene at 25°C for 30, 45, 60 and 90 minutes respectively, while tissues assigned to sub-groups B1 to B4 were cleared in pre-warmed xylene at 30°C for 30, 45, 60 and 90 minutes respectively and tissues assigned to sub-groups C1 to C4 were cleared in pre-warmed xylene at 35°C for 30, 45, 60 and 90 minutes respectively. As a consequence of this procedure, adequacy of nucleo-cytoplasmic staining characteristics and preservation of nucleo-cytoplasmic morphology were subsequently determined.

Results: Adequacy of nuclear and cytoplasmic staining were both assessed using a 2-point grading scale of 0 being inadequate and 1 being adequate, while preservation of both nuclear and cytoplasmic morphology were also assessed using a 2-point grading scale of 0 being poorly preserved and 1 being well preserved. Adequate nuclear and cytoplasmic staining were observed in tissues cleared in pre-warmed xylene at 25°C for 45 and 60 minutes, at 30°C for 30 and 45 minutes, at 35°C for 30, 45, 60 and 90 minutes. Well preserved nuclear morphology were observed in tissues cleared in pre-warmed xylene at 25°C for 30, 45 and 60 minutes, at 30°C for 30 and 45 minutes and at 35°C for 30, 45, 60 and 90 minutes. However, only tissues cleared at 35°C for 30, 45 and 90 minutes exhibited well preserved cytoplasmic morphology.                                                               

Conclusion: Adequate nucleo-cytoplasmic staining and well preserved nucleo-cytoplasmic morphology of tissues for histopathologic demonstration may be achieved rapidly by clearing tissues in 35°C pre-warmed xylene for as short as 30 minutes. 

Open Access Original Research Article

Complete Case versus Inverse Probability Weighting Methods of Fitting Incomplete Longitudinal and Survival Data Joint Models

D. O. Nyaboga, A. Mwangi, D. Lusweti

Current Journal of Applied Science and Technology, Page 1-10
DOI: 10.9734/cjast/2019/v34i230121

Missing data is a common problem in real word studies especially clinical studies. However, most people working with such data, often drop missing cases from individuals with incomplete observations that occur when patients do not complete the treatment or miss their scheduled visits. This may lead to misleading results and ultimately affect the decision of whether an intervention is good or bad for the patients under treatment. The comparison of Complete Case (CC) and Inverse Probability Weights (IPW) techniques of handling missing data in various models has been addressed, however little has been done to compare these methods when applied to joint models of longitudinal and time to event data. Therefore, this paper seeks to investigate the impact of assuming CC analysis on clinical data with missing cases, comparing it with IPW method when fitting joint models of longitudinal and survival data setting full data model as the baseline model. This paper made use of randomized aids clinical trial data. The model with Deviance Information Criteria (DIC) close to that of full data joint model is considered the best. From the results, joint models from full data, CC and IPW had DIC of 10603.94, 8410.33 and 10600.95 respectively. The joint model obtained from IPW data had a DIC too close to that of full data joint model as compared to model from CC data.

Open Access Original Research Article

Effect of Silica Nanoparticles on Activation Energy of Phenol Novolac Epoxy Resin/Unsaturated Polyester at Various Temperatures

Seyyed Mojtaba Mousavi, Seyyed Alireza Hashemi, Ali Mohammad Amani, Amir Savar Dashtaki, Mohammad Reza Jamshidi, Hamed Fateh, Farhad Ghani Zadeh, Sajad Alikhani Far

Current Journal of Applied Science and Technology, Page 1-9
DOI: 10.9734/cjast/2019/v34i230122

In the current study, the activation energy of modified phenol novolac epoxy (PNE) resin with unsaturated polyester (UPS) and silica nanoparticle (SN) at different filler loadings was investigated. In this case, effect of silica nanoparticles as a nano-size filler on the activation energy of PNE/UPS blend was evaluated. For this matter, tetraethylene pentamine (HA-11) which is an amine hardener was used as curing agent. SNs were dispersed in the mixture using ultrasonic equipment to prevent their agglomeration. The curing reaction of epoxy-based resins is exothermic. In this regard, the dynamic curing process was studied using differential scanning calorimetry (DSC) in four different heating rates, including 2, 5, 10 and 15 °C/min. Besides, various methods, including Ozawa, Flynn-Wall, Friedman and Butchart-Denilez were used to determine whether the activation energy of PNE/UPS blend or the best method for calculation of activation energy. Achieved results showed that the addition of SNs to the matrix can increase the activation energy and thus increase the curing time.

Open Access Original Research Article

Similarity Solution of Flow, Heat and Mass Transfer of a Nanofluid Over a Porous Plate in a Darcy-Forchheimer Flow

A. Falana, A. Alao Ahmed

Current Journal of Applied Science and Technology, Page 1-14
DOI: 10.9734/cjast/2019/v34i230123

In this work, a similarity solution of the flow, heat and mass transfer of a nanofluid over a porous plate in a Darcy-Forchheimer flow is explored. The nanofluid model includes Brownian motion and Thermophoresis diffusion effects. The governing transport equations are made dimensionless using similarity transformation technique which reduce them into ordinary differential equations with the associated boundary conditions. The equations are then solved numerically using the classical fourth order Runge-Kutta method and the results are benched marked with available results in literature and are found to be in good agreement. The results for the flow velocity, the shear stress, the temperature distribution, the nanoparticle volume concentration, the skin friction coefficient, the reduced Nusselt number, and the reduced Sherwood number, are presented graphically illustrating the effects of permeability, inertia, thermophoresis, Brownian motion, Lewis number and Prandtl number on the flow. Our analysis shows, among others, that the Nusselt number is a decreasing function, while the Sherwood number is an increasing function of the thermophoretic number

Open Access Original Research Article

Physical Activity Level in Relation to the Nutrient Intake of Elite Athletes

Aditi Sewak, Neerja Singla, Rohini Jain

Current Journal of Applied Science and Technology, Page 1-10
DOI: 10.9734/cjast/2019/v34i230124

Aim: The present study was conducted to study the relationship between the nutrient intake and physical activity level of 120 (16-25 years) elite athletes.

Methods: Athletes were selected from 5 universities of Punjab, participating in 4 sports viz. hockey, athletics, badminton and lawn tennis and their nutritional status and sports performance was assessed.

Results: The findings suggested that athletes had a normal Body Mass Index (BMI) and the energy, protein and iron intake of all the athletes was lower than dietary recommendations (61, 61.3 and 35% respectively). However, percent adequacy of calcium (91%), vitamin A (94.7%) and vitamin C (183%) was adequately high among overall athletes. Majority of athletes (51.7%) had vigorously active lifestyle; 44.2% had moderately active lifestyle.

Conclusion: Intake of nutrients was positively correlated with physical activity.

Open Access Original Research Article

Comparative Analysis of Per Second Billing System of GLO, MTN, Etisalat, Airtel and Visafone in Nigeria

Kamoru Oluwatoyin Kadiri, Samuel Oluwaseun Lawal

Current Journal of Applied Science and Technology, Page 1-8
DOI: 10.9734/cjast/2019/v34i230125

This study compares per second billing system of network providers such as MTN, AIRTEL, GLO, ETISALAT and VISAFONE in Nigeria. The area of research cluster in this study is to assess price, usage and beneficial Comparisons among communication companies (Network providers) along with their market competition in Nigerian economy and to evaluate the factors that influence the decisions of Nigerian telecommunication commission on price changes. Data of network subscribers and other network bundles were collected via Nigeria Communication Commission (NCC) database and other valuable medium. Comparison of active, inactive and installed capacity was inferred using multiple bar charts for efficient comparison. The study, with the aid of drift analysis, surveyed the effects of the competition on availability, quality and cost of telecommunications services in Nigeria.

The method of price comparison employed in this study centered on the five telecommunication network operators’ tariff plans (both prepaid and postpaid), an approach which defined separate service price data on the basis of service usage levels, service merits, economic factor, tariff rate and accessibility. This study showed that, telephone density (teledensity) increased from 97.60 to 108.11. It was inferred that, Visafone offers better per second billing system, follow by MTN Nigeria. Airtel Nigeria per second billing system is also moderate; Globacom Limited followed Airtel Nigeria; Etisalat tariff rate would have follow Visafone as the second best had it been it does not offers its service with access fees. It was observed according to the official data that, MTN Nigeria has the highest number of subscribers, follow by Globacom Limited, Airtel Nigeria, Etisalat and Visafone Limited in rapid succession. Hence, factors that determine the rate of subscription to individual network service among others, include, age of the network, quality service render, network coverage, tariff rate, accessibility, benefits, etc.

Open Access Original Research Article

Resource Allocation Scheme for One-to-Many Cooperative Wireless Systems Using the Bidding Game Strategy

Oluseye Adeleke, Wasana Boonsong

Current Journal of Applied Science and Technology, Page 1-14
DOI: 10.9734/cjast/2019/v34i230126

In this paper, we propose a new scheme for optimal resource (i.e, power) allocation in a cooperative wireless communication system, using a type of game called the Bidding game. Previous related works have all considered networks with multiple source nodes interacting with either single or multiple relays, without paying so much attention to how partners are selected for cooperation. However because of the importance of partner selection as an integral part of an efficient cooperative communication network, which also includes resource allocation, we propose this new game-based resource allocation scheme, in which the conventional theories of economic bidding are applied. In this work, we model the cooperative communication network as a single-user, multi-relay system in which the source acts as the auctioneer while the relays or partners act as the bidders in the game. The resource being auctioned here is power. The relay which offers the highest bid in terms of price is first selected by the source node and then allocated power by the source node. Our proposed scheme is aimed at answering the question of how maximally or optimally the power should be allocated in the network by the source node so as not to violate the power constraint. We show that there exists bidding and pricing mechanisms or strategies that lead to the maximization of network throughput or utility in cooperative communication networks. We also see in our simulation results that there is convergence to the Nash equilibrium which proves the correctness of our scheme.