The Effect of Weather Factors on the Population Density of Oxycarenus spp. (Hemiptera: Lygaidae) on Roselle and Kenaf

Roselle, Hibiscus sabdariffa and Kenaf, Hibiscus cannabinus are two important fibre crops in most parts of Africa. Insect pests are one of the major constraints in the production of these crops. The cotton seed bug Oxycarenus spp. attacks Roselle and Kenaf during the seed formation stage and cause reduction in seed viability. This study examined the effect of weather factors namely, relative humidity, temperature, sunshine and soil evaporation on the population density of Oxycarenus spp. on Roselle and Kenaf during the planting seasons 2012 and 2013. The treatments consisted of two types of Roselle (Green-calyxed and Redcalyxed) and Kenaf. The experiment was laid out in the field using Randomized Complete Block Design and the treatments were replicated four times. The results showed that the population of Oxycarenus spp. was significantly (p<0.05) higher on green-calyxed H. sabdariffa and red-calyxed H. sabdariffa than on Kenaf in 2012 and 2013. The differences in the density of the bug per fruit on green-calyxed H. sabdariffa and redcalyxed H. sabdariffa were significant in the two planting seasons. Relative humidity in the morning and maximum temperature correlated positively and negatively, respectively with the density of Oxycarenus spp. during the two planting seasons. Sunshine hours per day correlated positively, while soil temperature and soil evaporation had a negative correlation with the bug density. This information on the seasonal variation in the bug density and its relationship with weather factors could be used in pest forecasting for these fibre crops which is an important tool in formulating a successful pest management programme.Keywords: Malvaceae, Fibre crops, weather factors, Oxycarenus spp., pest management, planting seasons, pest density

Radio access evaluation of cellular network in Akure metropolis, Nigeria

The higher subscription, relative importance of voice calls, client’s complaints and economy depression that now make clients to get value for money paid and need for more revenue by mobile network operator (MNOs) justified this work. The objective of this work is to measure, analyse, evaluate the performance of MNOs, and to recommend ways to improving their quality of service (QoS). Drive test approach was used for the measurements and statistical methods for the analysis. Results of the analysis shows that the quality of Voice service offered by MNOs is not optimal and there is room for improved quality service. Based on the key performance indicators, the mobile operators did not perform up to expectation. There are differences in the quality of voice service offered across mobile network operator networks based on the time of the day and the area under consideration. MNO1, MNO2, MNO3 and MNO4 gave varying quality of service. MNO4 had absolutely no dropped calls and performed best and consistently gave a retainability ratio above the target. MNO1 performance metrics were below the key performance indicator thresholds given by the Nigerian Communication Commission.Keywords: Performance Evaluation, Quality of Service, Voice Services, Mobile Communicatio

EVALUATION OF BIOGAS POTENTIALS OF Cymbopogon citratus AS ALTERNATIVE ENERGY IN NIGERIA

This research explored the potentials of Cymbopogon citratus (Lemon Grass) for biogas production as a cost effective alternative energy source in Nigeria. The Cymbopogon citratus was crushed to small sizes between 20 to 50mm and pre-fermented for 40 days in a PVC drum. Six (6) kg of the pre-fermented Cymbopogon citratus was mixed with water in ratio 1:1 w/v to form slurry and digested for 30 days. The floating drum gas collection system was used to collect the gas after it was passed through water and lime respectively for scrubbing. A total of 0.125m3 (6.95x10-4 m3/kg/day) and 0.0897m3 (4.98x10-4 m3/kg/day) of biogas was produced from the Cymbopogon citratus before and after scrubbing respectively. The gas produced was used for cooking test. The scrubbed gas had higher cooking rates for both water and rice respectively (0.12L/min and 0.0052L/min) while the cooking rates for unscrubbed gas were 0.079L/min and 0.0036L/min respectively. During this period, daily ambient temperatures of the research environment varied from 310C to 420C while the digester temperature fluctuated between 28oC and 36.70C. The pH of the medium fluctuated optimally between 6.5 and 7.8. The research demonstrated that Biogas could be produced from Cymbopogon citratus in quantity and quality comparative with those in literatures

Fertilizer and Sanitary Quality of Digestate Biofertilizer from the Co-digestion of Food Waste and Human Excreta

This research was aimed at assessing the fertilizer quality and public health implications of using digestate biofertilizer from the anaerobic digestion of food wastes and human excreta. Twelve (12) kg of food wastes and 3 kg of human excreta were mixed with water in a 1:1 w/v to make 30-l slurry that was fed into the anaerobic digester to ferment for 60 days at mesophilic temperature (22–31 �C). Though BOD, COD, organic carbon and ash content in the feedstock were reduced after anaerobic digestion by 50.0%, 10.6%, 74.3% and 1.5% respectively, nitrogen, pH and total solids however increased by 12.1%, 42.5% and 12.4% respectively. The C/N ratios of the feedstock and compost are 135:1 and 15.8:1. The residual total coliforms of 2.10 � 108 CFU/100 ml in the digestate was above tolerable limits for direct application on farmlands. Microbial analysis of the digestate biofertilizer revealed the presence of Pseudomonas, Klebsiella, Clostridium, Bacillus, Bacteroides, Penicillum, Salmollena, and Aspergillus. Klebsiella, Bacillus, Pseudomonas, Penicillum and Aspergillus can boost the efficiency of the biofertilizer through nitrogen fixation and nutrient solubility in soils but Klebsiella again and Salmollena are potential health risks to end users. Further treatment of the digestate for more efficient destruction of pathogens is advise

Pavement construction using self-compacting concrete: Mechanical properties

This experimental study assessed the strength properties of some selected Portland limestone cement for self-compacting concrete in pavement construction. Self-compacting concrete offers many advantages in the construction world but its utilization in pavement construction is low. To achieve the aim of this research, four brands of grades (42.5 and 32.5) of the cement were used. Cement brands A, B, C and D were used in SCC samples tagged as SCC 1, 2, 3 and 4 respectively. To this end, rheological tests were carried out using the L-Box, V-Funnel and slump cone. Additionally, mechanical properties (compressive, split tensile and flexural strength) of the hardened concrete were evaluated. The compressive and flexural tests were determined at 3, 7, 14, 21 and 28, 56 and 91 days of curing. SCC 4 with Brand D showed the highest strength at 3 days but had the lowest at 28 days and 91 days. However, SCC 1 with brand A showed the highest strength at maturity. Additionally, the result showed that the percentage difference in the compressive strength of the SCC 1 and the other mixes were 27.6%, 27.7% and 40.7% while 18.1%, 27.5% and 42.1% increment was recorded for the flexural strength of SCC 1, SCC 2, and SCC 3 respectively. However, SCC 4 had the best rheological properties, though the lowest strength. A positive strong correlation was recorded for the mechanical properties of the SCC mixtures. Moreover, the relationship between the mechanical properties and age followed a logarithmic trend with R2 value that ranges from 0.86 to 0.977 which established the robustness. Ultimately, the result revealed that SCC 1 with brand A proved to be the most suitable for SCC in rigid pavement construction

Optimization of biogas from chicken droppings with Cymbopogon citratus

Optimization of biogas production and quality from chicken droppings by anaerobic co-digestion withCymbopogon citratuswas investigated. The anaerobic digestions of chicken droppings, chicken droppingswithC. citratusas well asC. citratusalone were carried out for a period of 30 days at an average ambienttemperature of 33.1�2�C using identical reactors (AeC) respectively. Results obtained indicate thatchicken droppings produced on the average 1.8 L/kg/day of biogas, co-digestion of chicken droppings andC. citratusproduced 1.3 L/kg/day of biogas whileC. citratusalone produced 1.0 L/kg/day with estimatedaverage methane content of 41.71%, 66.20% and 71.95% for reactors AeC respectively. The water boilingrates of biogas from chicken droppings, chicken droppings withC. citratus, andC. citratusalone were0.079 L/min, 0.091 L/min and 0.12 L/min respectively, after the gases were scrubbed with water andslaked lime. It was observed that notwithstanding the higher biogas volumetric yield from chickendroppings digested alone, the co-digestion of chicken droppings withC. citratushad better gas qualitywith respect to the methane content present and cooking rate. This study has shown that the methanecontent of biogas from animal manure substrates could be improved by co-digestion with energy plant

Smart Grid Systems in Nigeria: Prospects, Issues, Challenges and Way Forward

The ability of the power system to deliver to its consumer electrical energy at an expected level of reliability is correlated with the economic development of a country. The Nigerian power system faces many challenges, varying from overdue infrastructure maintenance, obsolete tools and appliances, insufficient electricity supply, corruption, etc. A gradual shift from manual to smart digital technologies include; smart metering, distributed generation (renewable energy and microgrid), and management using Information and Communication Technology (ICT) tools. In response, research, investments, and upgrade to the power sector are fundamental. This paper discusses and analyses the various smart grid technologies utilised in the Nigerian power system with their effects, impacts, deployment, and integration into the traditional Nigerian power grid. Also discussed are issues and challenges of smart grid deployment and ways of mitigating these challenges

Assessment of Chemical Inhibitor Addition to Improve the Gas Production from Biowaste

The coexistence of sulphate-reducing bacteria and methanogenic archaea in the reactors during the anaerobic digestion from sulphate-containing waste could favor the accumulation of sulfide on the biogas, and therefore reduce its quality. In this study, the effect of sulphate-reducing bacteria inhibitor (MoO−2 4 ) addition in a two phase system from sulphate-containing municipal solid waste to improve the quality of the biogas has been investigated. The results showed that although SRB and sulphide production decreased, the use of inhibitor was not effective to improve the anaerobic digestion in a two phase system from sulphate-containing waste, since a significant decrease on biogas and organic matter removal were observed. Before MoO−2 4 addition the average values of volatile solid were around 12 g/kg, after 5 days of inhibitor use, those values did exceed to 28 g/kg. Molybdate caused acidification in the reactor and it was according to decrease in the pH values. In relation to microbial consortia, the effect of inhibitor was a decrease in Bacteria (44%; 60% in sulphate-reducing bacteria) and Archaea (38%) population

Development of a Crowdsourced-based Mobile Application for Measuring Quality of Internet Service Offered by Mobile Network Operators

Wireless mobile internet is migrating towards an integrated system of internet and mobile communication network to fulfill the future of mobile network requirement: ubiquitous communication, where mobile users move freely almost anywhere and have access to the internet, communicate with anyone, anytime with any application using the best service available. This demands rapid progress in mobile communication networks and their internet technologies. This research project on the analysis of the Quality of Service (QoS) provided by Mobile Network Operators (MNOs) in the cellular internet networks. It aims to analyze and address the QoS of the internet network experienced by the user. QoS monitoring and analysis require the processing of large amounts of data and knowledge of which kinds of applications the traffic is generated by. To obtain satisfactory QoS based on internet network analysis, some network metrics must be measured and monitored at a regular time interval. In this research work, the network metric that will be measured for the internet service are signal strength, download speed, upload speed, and network transaction latency. This network metrics data will be collected from the consumer’s mobile device by the use of a crowdsourcing mobile application that is installed on the consumer’s mobile device. The investigation will cover mobile communication network providers in Nigeria. The data collated is then evaluated and analyzed

Comparative evaluation of biogas production from Poultry droppings, Cow dung and Lemon grass

The study explored the production of biogas from Lemon grass, Cow dung and Poultry droppings. Thethree substrates were pre-fermented according to standard methods. Six (6) kg of each pre-fermentedsubstrate was mixed with water in ratio 1:1 v/v to form slurry and digested for 30 days. A total of0.125 m3, 0.191 m3and 0.211 m3of biogas were respectively produced from the Lemon grass, Cow dungand Poultry droppings with deviations of 0.00234 m3, 0.00289 m3and 0.00484 m3respectively. The cook-ing test carried out revealed that the scrubbed gas had higher cooking rates for water (0.12 L/min,0.085 L/min and 0.079 L/min for Lemon grass, Cow dung and Poultry droppings respectively) while thecooking rates for unscrubbed gas were 0.079 L/min, 0.064 L/min and 0.06 L/min respectively. The pH ofthe medium fluctuated optimally between 6.5 and 7.8. The research demonstrated that Lemon grass pro-duced less volume but better quality biogas compared to Cow dung and Poultry droppings