Aerosols Loading Trends and its Environmental Threats Over Cotonou-Benin.

Environmental security is totally relegated in countries of West Africa. The monitoring of the aerosols loading over Cotonou was the aim of this study. The outcome of our finding has salient links to food security, aviation and communication industry, thermal comfort and climate system of Benin. Cotonou is located on longitude 2.43°E and latitude 6.37°N. Fifteen years data were obtained from the multiangled spectro-reflectometry (MISR). The aerosol loading was monitored using analytical and statistical techniques. The aerosols retention over Cotonou was high in 2000 (69.91%), 2008 (72%) and 2013 (42.45%). This means that there is the possibility of higher rising sea levels and exposure to coastal erosion due to a twisted cloud formation

Rain Induced Cross Polarization on Satellite Communication in Nigeria

Microwave systems performance on satellite communication link operating above 10 GHz is increasingly degraded by rain when designing telecommunication systems. Cross polarization is one of the major source of signal degradation that affectthe frequency reuse when employed to boost capacity of the channel. The effect of cross-polarization in thirty-seven (37) stations in Nigeria were carried out using 10 years data obtained from Nigeria Meteorological Agency (NIMET) at the look angle from Nigeria Communication Satellite (NigComSat). International Telecommunication Union-Recommendation (ITU-R) model was used to for this study. The stations were grouped into six geopolitical zones in Nigeria which are Southwest (SW), Southeast (SE), South-south (SS), Northcentral (NC), Northwest (NW) and Northeast (NE). The results reveal that cross-polarization discrimination (XPD) become very poor as frequency (at Ku-band, Ka-band, V-band) increases especially at lower percentage of time (such as 0.001%, and 0.01%) unavailability. Hence XPD, at all frequencies is poorer in the southern part of Nigeria SE, SS and SW due to high rainfall rate. The results also show that only Northern part of the country will experience no interference at 0.01% as XPD is over 30 dB ITU-R base line for Ku-band transmission. However, for Ka-band and V-band at 0.001% and 0.01% unavailability of time interference will occur in all stations in Nigeria, but at 0.1% and 1% XPD is over 30 dB for all stations. This study will help in the adequate planning and designing of satellite telecommunication expansion in all the six geopolitical zones in Nigeria

Dynamics of Wind Strength and Wind Direction on Air Pollution Dispersion

The aim of the study is to examine the wind dynamics of Ota to understand certain atmospheric influences. An average volume of about four hundred and eighty thousand (480,000) wind speed data from the Davis weather station data logger of the department of physics, covenant university were considered. The data studied were divided into eight hour period, namely, night time (10pm to 6am following day); day time (6am to 2pm) and noon/evening time (2pm to 10pm). Of the three periods studied, wind speed at night time was observed to be the least. December, January and February (DJF) data set was statistically analyzed. The correlation coefficient values recorded with the wind flow for the months of DJF are 0.28 for December, 2012, 0.20 for January, 2013, and 0.39 for February, 2013. While a significant low correlation coefficient values observed for the months of March, April and May (MAM) are 0.02 for March, 0.01 for April and 0.04 for May. A further daily analysis was conducted for February. A significant occurrence of atmospheric stagnation was observed in the night time readings of February 3, 2013 with an exceptional low average wind speed of 0.143 ms-1. While February 17, 2013 recorded all day normal air ventilation with wind speed of 1.443 ms-1, 1.998 ms-1, 4.482 ms-1 for night, day and noon/evening time respectivel

Theoretical Study of Aerosols Loading and Retention Over Bolgatanga, Ghana

The aerosols loading and retention over West Africa have grave effect on life-forms through the impact on health, farming, rainfall pattern, cloud formation, and regional climate. Bolgatanga can be found on the latitude and longitude of 10.78°N and 0.85°W, respectively. This research is focused on an investigative consideration of the negative effect of atmospheric aerosols over Bolgatanga in Ghana through a conceptual model using analytical and descriptive statistical methods with MATLAB curve-fitting tool. The model was verified using aerosol optical depth data set from satellite imagery—multi-angle imaging specto-reflectometer (MISR)—obtained over a period of 13 years. The highest percentage increase of aerosol retention was 64.27% over the research site. The model was used to estimate the atmospheric constants as 0.67, tuning constants as 0.24, and phase difference as ± π 4 . The physical interpretation of the results was analyzed systematicall

Low Cost Real-Time Portable Pulse Oximeter with Wireless Network

To facilitate quicker detection of symptoms of cardiovascular and respiratory disorders, the use of smaller portable wireless sensors which consume less power is an essential requirement. Wireless pulse oximeter are convenient devices which aid to remotely monitor a patient’s heart rate and blood oxygen saturation (SpO ), The result of this studyshows a developed portable, low cost device which can be used to measure the heart rate, and SpO of an individual. To this end, a small pulse oximeter was developed; which used an elastic transmissive mode finger probe to measure the heart rate and SpO . The device could successfully measure these vital signs and display on a LCD screen. The readings taken from individual for a period of one minute shows average heart rate of 75.6 bpm at zero offset and the average SpO readings derived from the device was 98.7% at zero offset. The model designed is also rechargeable to make it more sustainable for use in rural areas where there is insufficient power supply. The prototype pulse oximeter designed is portable, consumes less power and capable of sending processed measured data to an online database via a WLAN network thereby satisfying the criteria for sustainable telemedicine.This device is therefore recommended for use in local hospitals and remote medical centre to aid easier detection and prevention of critical medical disease

A Tropical Model for Analyzing Radio Refractivity: Selected Locations in North Central, Nigeria

The effect of climatic global change has altered the meteorological factor of the ITU model especially in the lower atmosphere. The refractivity results obtained in an active tropical region of West Africa need to be reappraised. A model known as the Tropic model was derived and tested using NOAA data set. The data set were obtained from Meteorological data obtained from NOAA (USAF) Climatology center. Radiosonde data set was at least 39 years between 1973-2012 for six stations within the North-central of Nigeria. It was observed that the Tropic model detected tropospheric perturbations caused by the extensive influence of aerosol influx. This was confirmed by the hourly refractivity obtained from the ITU model. Hence, the ITU model and the Tropic model are complementary to each other for an accurate terrestrial radio links calculation

Sectional Investigation of Seasonal Variations of Surface Refractivity and Water Vapour Density over Nigeria

The accurate knowledge of radio refractive and water vapour density of the troposphere is important in the planning, budgeting and designing of transmission and reception of radiowave signals on earth-space path. Hence, there is the need to adopt more precise techniques to analyze the seasonal variation of refractivity and water vapour density over Nigeria. The seasonal variation of refractivity and water vapour density was studied using thirty-nine years meteorological data for forty-eight (48) stations over Nigeria. The forty-eight stations were grouped into nine vegetation and two major climates in Nigeria. Harmonic analysis approach was used in addition to the monthly mean computation. The results show that Forests zones values of refractivity and water vapour density are higher than Savannahs zones values. The refractivity value increases from about 281 N units at Sudarian Woodland in January to about 383.6 N units at Mangrove station in June. Water vapour density value increases from about 5.18 g/m3 at Brush and Thicket station in November to maximum value of about 22.36 g/m3 at Swamp Forest station in May. Results also show that over 80% variations in refractivity and over 70% variations in water vapour density are revealed in the first three harmonics at all the nine stations. The results indicate that the method of harmonic amplitudes and phases give a more analytical comparison between predictions model and observational data

Re-Integrating Vocational Technical Skill Acquisition into the Educational Curriculum: Capacity Building for Future Professionals

One of the observable problems facing most developing nations today is the non-availability of adequately trained and well-motivated professionals with the capacity to solving problems of national development. Many University graduate professionals complain of unemployment. However, there exist substantial employment opportunities in Africa and other developing nations but the major challenge being that, the skills to match up with imminent challenges are missing. There is, therefore a need to re-integrate vocational technical skill acquisition into the Educational Curriculum for young professionals with proper mental orientation and practical skills for solving societal problems. This paper underlined the necessity of re-integrating vocational technical education (VTE) courses with special targets on sustainability and capacity building aspect of citizenry lives with a view to ascertain the empowerment of students for self employment after graduation. In a bid to achieve this, the current pedagogical approach and curriculum dynamics employed at the Architecture and Civil Engineering Department of Covenant University Ota, Nigeria was evaluated. Specific reference was made in terms of knowledge application from fabrication, construction in timber, reinforced concrete and steel to the main architectural design project. As regards the capacity building development aspect within the architectural and civil engineering education, the application of the respective vocational technical knowledge, obtained through lectures, site works and work shop practices were of major essence in collaborative design projects. It is expected that the indispensability of VTE courses for a successfully-integrated design would bind every element of the design together in different scales. In this way, the sustainability component of the designs in the studio, engineering workshop practice and energy-efficient design would be put to use. The study recommended the investigation and application of all critical elements of VTE-based curriculum development for a sustainable capacity development of emerging future professionals

Seasonal Variation of Surface Radio Refractivity and Water Vapour Density for 48 Stations in Nigeria

The monthly and seasonal variation of surface refractivity and water vapour density were studied using thirtynine years meteorological data for forty-eight stations in Nigeria. The factors which influence the transmission of radio signals operating within the troposphere are water vapour and refractivity. The results show that the surface refractivity and water vapour density generally have higher values during the rainy season than dry season at all station studied. Furthermore the results show that the value of surface refractivity and water vapour density varies from about 263 N-units and 3 g/m3 in arid region of Nigeria (North East) to about 393 N-units and 23 g/m3 in the coastal area of Nigeria (South West) respectively. For optimal performance of terrestrial radio link across Nigeria it is required to account for the variability of these parameters for optimal systems design

Geophysical investigation into the integrity of a reclaimed open dumpsite for civil engineering purpose

Structural failure is one of the concerns of earth scientists in the in the recent time. Most of the building engineers neglect investigation into the subsurface structure prior to construction without taking into cognizance the soil type and its variation which is one of the contributing factors to frequent building collapse in this era. Integrated geophysical methods involving ground magnetic, Very Low Frequency-Electromagnetic (VLF-EM) and Vertical Electrical Sounding (VES) were adopted with a view to investigating into the integrity of a reclaimed open dumpsite in Oyo for civil engineering worthiness. Three (3) traverses were occupied for ground magnetic and VLF-EM survey. A total length of 100 m was occupied in each traverse along E-W orientation with inter-station spacing of 10 m. Six (6) VES stations were occupied along two geoelectric profiles in the study area. The ground magnetic study showed magnetic highs and lows both on the profiles and the generated 2-D map. The magnetic highs are competent zones for civil engineering construction while magnetic lows are incompetent zones. The VLF result revealed conductive and non-conductive zones. More than half of the area of study is characterized with conductive signatures. Conductive zones are regarded as the incompetent zones while the non-conductive zones are regarded as competent zones. The VES result showed that the five out of six VES points occupied are underlain with fractured bedrock while only VES 3 showed fresh bedrock. It is concluded that the study area unsuitable for the construction of giant structure