M.R. Usikalu

Data on the radiometric survey over a kaolinitic terrain in Dahomey Basin, Nigeria

This article consists the in situ data sets of activity concentrations of radionuclides (K-40, Th-232 and U-238) and gamma radiation dose rates measured about 1u202fm above a kaolinitic terrain in Ifonyintedo, Dahomey Basin, SW Nigeria. Nineteen (19) data points were randomly occupied at the lower axis of the kaolin field using a hand-held detector known as Super-Spec (RS 125). At each data point, the measurements were taken four times, while their averages and standard deviations were estimated in order to ensure accuracy. The radiometric survey was carried out between December, 2017 and January, 2018. The data sets were processed and analyzed via a descriptive statistics. The data can be explored further by estimating the radiological risks to the miners on the field, and to correlate the activity concentrations of the data with the activity concentrations of the tiles that are produced from the kaolin deposits in Ifonyintedo. Furthermore, the data from this article could be compared with other data acquired over a kaolinitic terrain across the globe.

Dataset of surface water vapour density in southeast, Nigeria

In this data article, analysis of surface water vapour density in Southeast, Nigeria were reported. The meteorological data were obtained for the period of 39 years between 1973 and 2012 from National Oceanic and Atmospheric Administration (NOAA) Climatology Centre. Five stations considered in the research area includes: Enugu, Onitsha, Abakaliki, Aba and Ihiala. Descriptive statistics were used to show an increase in monthly variation of surface water vapour density (SWVD) minimum value of about 7.15u202fg/m3 at Enugu in January to maximum value of about 21.96u202fg/m3 at Onitsha in April. Hence, the seasonal variation for South East indicate peak value within the months of March to May in the rainy season and a lower value around December to February which is the dry season. The results from this data will help engineers in proper design and planning of radiowave propagation and satellite communication systems in southeastern, Nigeria.

Analysis of non-rainy attenuation on earth-space path in Ota, Southwest Nigeria

Propagation effects due to atmospheric gases and tropospheric scintillation requires naccurate modelling in the design of satellite communication systems. The combination of the ntwo attenuation phenomena was observed within the period of August 2014 to December 2015. nThe result of this paper presents the on-going observation and data analysis of non-rainy nattenuation on earth-space path in Ota, Southwest Nigeria. Results of clear-sky attenuation nvary between 0 dBm and 4.85 dBm in January and February 2015 respectively. While a value nof 4.23 dBm and 4.75 dBm were observed in October 2014 and 2015 respectively. The results nwill be useful for satellite communication system design and will be submitted to ITU-R Study ngroup 3 Databank.

Radiation from Visual Display Unit

The radiation from different types of Visual Display Units (VDU) (that is, Liquid Crystal nDisplay (LCD) and Cathode Ray Tube (CRT)), projector and interactive screen were examined using a nCell Sensor Extremely Low Frequency (ELF) detection meter. The study revealed that ELF radiation in nCRT VDUs is eight (8) times greater than in LCD VDUs. The mean ELF obtained from interactive screen nat 30 cm was 1.6 mG and 1.9 mG at start-up and after 3 hours of use respectively with a mean value of n1.03 mG for a distance of 100 cm at start up. The mean ELF radiation from the projector screen at a ndistance of 10 cm is 0 mG, while that of interactive screen is 2.4 mG at the same distance. Thus, the nstudy suggested that, projector and screen is better than interactive screen when making presentation nconsidering the closeness of user to the interactive screen throughout the course of presentation.

Construction of an in-situ smart device that measures some basic environmental factors for agricultural monitoring

Most of the rural agricultural and extension officers have no access to the daily nvariations in meteorological data that affect the growth and yield of crops. This is as a result of nlittle or no access to the data that could be used to predict the best agricultural practices for noptimum output in the rural environments. In this work, a portable and user friendly smart nAutomated Weather Station (AWS) was constructed. The device that is programmed with nArduino UNO is capable of measuring the temperature, relative humidity and moisture content nof the soil. The performance evaluation of the device was observed in the laboratory and onsite n(Covenant University farm) both on the sunny and rainy days respectively. It was revealed nthat there is positive linear relationship between the volume of water added to the soil sample nand the soil moisture content in the laboratory measurements. The on-site measurements nshowed that the temperature is inversely proportional to the relative humidity and soil moisture ncontent. This device is efficient in taking the short-term essential parameters that could nimprove the yield of agricultural products in the rural environments if properly utilized.

Review on Li-Fi: an advancement in wireless network communication with the application of solar power

Light Fidelity, commonly referred to as Li-Fi is a technology that was introduced by na German physicist called Herald Hass. This technology in its own uniqueness considers the nuse of light (Light Emitting Diode, LED to be specific) as its medium of delivering high speed ncommunication that complies with standard IEEE 802.15.7 bidirectional communication nstandard. This optical means of communications is also known as visible light communication. nIt is safer when compared with Wi-Fi network. This paper will focus on Li-Fi applications, ncomparison with existing technologies like Wi-Fi and the inclusion of an alternative source of npower i.e., solar power, as a means of effectively optimizing on the availability and naccessibility of the benefits in places where erratic or total power outage is a common trend.

Analysis and comparison of tropospheric scintillation prediction models at Covenant University

Knowledge of tropospheric scintillation is an important phenomenon in the design of nsatellite communication system. One year (January 2015-December 2015) scintillation data nextracted from Astra 2E/2F/2G Satellite link measurement installed at Covenant University, nOta (Lat: 6.7 oN, Long: 3.23 oE) southwest Nigeria, at an elevation angle of 59.9o and a nfrequency of 12.245 GHz was used in this study. The analysis and the result were compared nwith some reputable scintillation prediction models so as to obtain best performance model for nOta region. From the result, it was discovered that the Karasawa model gives the lowest npercentage error rate for both fade and enhancement of about 0.57% at 0.1 percentage of time nand 6.93% at 0.01 percentage of time respectively and therefore was best found fit for the nprediction of propagation impairment for the region. However, the model should be tested nfurther using higher frequency band such as Ka and V bands to confirm the accuracy of the nmodel. The information provided in this study will help in fade margin for antenna sizing and nperformance needed for satellite communication link in the region.

Comparison between experimental and satellite temperature datasets in Covenant University

This article contains the ground and satellite meteorological data sets of clear-sky temperature events for five years (2012–2016) in Covenant University, Ota, Ogun State, Nigeria. The satellite data were obtained from Atmospheric Infrared Sounder (AIRS) while the ground data information were acquired from Davis weather station data logger-vantage pro2. These data were acquired from propagation study that used same location (Lat: 6.67°N and Long: 3.23°E) for both satellite data and radiometer directed along the same path by providing information about the temperature. The data sets were assessed and evaluated by means of a descriptive statistics. There was perfect agreement between the two data. The peak temperature events occurs between the months of November and April for the five years of observation for both Ota and AIRS Satellite. The data from this article can be used for further studies on non-rainy attenuation effect in the study area.

Cancer risks from chest radiography of young adults: A pilot study at a health facility in South West Nigeria

The recommendation of chest radiography for school admission and employment purposes should be discouraged due to the risks of radiation especially cancer induction. It is therefore imperative to keep diagnostic radiation doses as low as possible. This dataset presents the entrance surface dose, effective dose, bone marrow dose, breast dose, lung dose and the incidence cancer risks from chest radiography of 40 young adult females. The mean incidence cancer risk to participants is 1: 20,000 for solid cancers. The data revealed the significant factors influencing the entrance surface dose and incidence cancer risks.

Data on the porphyrin effect and influence of dopant ions on Thaumatococcus daniellii dye as sensitizer in dye-sensitized solar cells

In this work, data on the effect of porphyrin characteristic of UV/VIS absorption of Thaumatococcus daniellii (T. daniellii) dye-sensitized solar cells sensitized with different electrolytes were presented. The influence of dopants from 1u202fg/100u202fml electrolyte: distilled water and applied time difference of 3u202fmin is observed on the photovoltaic characteristics and performance of the deposited thin film. The output efficiency and incident photon to conversion efficiency of T. daniellii dye-sensitized solar cells was acquired and could be further used as a model for designing dye-sensitized solar models as substitute for silicon solar cells