18 research outputs found
Altering rainfall patterns through aerosol dispersion
The possibility of recirculation mechanism on rainfall patterns is salient for
sustenance of the human race through agricultural produce. The peculiarity of the lower
atmosphere of south west region of Nigeria was explored using theoretical and experimental
approach. In the theoretical approach, the reconstruction of 1D model as an extraction from the
3D aerosol dispersion model was used to examine the physics of the recirculation theory. The
experimental approach which consists of obtaining dataset from ground instruments was used
to provide on-site guide for developing the new recirculation theories. The data set was
obtained from the Davis weather station, Nigeria Meteorological agency and Multi-angle
Imaging Spectro-radiometer (MISR). We looked at the main drivers of recirculation and
propounded that recirculation is a complex process which triggers a reordering of the mixing
layer- a key factor for initiating the type of rainfall in this region
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
a German physicist called Herald Hass. This technology in its own uniqueness considers the
use of light (Light Emitting Diode, LED to be specific) as its medium of delivering high speed
communication that complies with standard IEEE 802.15.7 bidirectional communication
standard. This optical means of communications is also known as visible light communication.
It is safer when compared with Wi-Fi network. This paper will focus on Li-Fi applications,
comparison with existing technologies like Wi-Fi and the inclusion of an alternative source of
power i.e., solar power, as a means of effectively optimizing on the availability and
accessibility of the benefits in places where erratic or total power outage is a common trend
Development of a solar charged laboratory bench power supply
This product is an improvement on available DC laboratory bench power
supply. It is capable of delivering low voltage Alternating Current (AC) and Direct
Current (DC) to carry out basic laboratory experiment for both secondary schools and
also at higher education institutions. The power supply is capable of delivering fixed
DC voltages of 5V, 9V, 12V, the variable voltage of between 1.25–30V and a 12V AC
voltage. Also Incorporated is a USB port that allows for charging cell phones and
other mobile devices, and a dedicated 12V DC output to power 5-7 Watt LED bulb to
provide illumination in the laboratory for the instructor who may need to work at night
in the absence of utility power
Radiation from Visual Display Unit
The radiation from different types of Visual Display Units (VDU) (that is, Liquid Crystal
Display (LCD) and Cathode Ray Tube (CRT)), projector and interactive screen were examined using a
Cell Sensor Extremely Low Frequency (ELF) detection meter. The study revealed that ELF radiation in
CRT VDUs is eight (8) times greater than in LCD VDUs. The mean ELF obtained from interactive screen
at 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
1.03 mG for a distance of 100 cm at start up. The mean ELF radiation from the projector screen at a
distance of 10 cm is 0 mG, while that of interactive screen is 2.4 mG at the same distance. Thus, the
study suggested that, projector and screen is better than interactive screen when making presentation
considering the closeness of user to the interactive screen throughout the course of presentation
Performance and Evaluation of Eight Cloud Models on Earth—Space Path for a Tropical Station
This is a review of eight cloud models and a statistical analysis of radiosonde data and cloud cover data in order to obtain attenuation distributions and cloud cover statistics for a tropical location, Ota (6.7oN, 3.23oE) at a computed elevation angle of 56.18o to an Astra 2B satellite located at 31.5oE. Cloud models are mathematical algorithms scientifically designed to predict cloud attenuation impact on propagating electromagnetic signals in the troposphere, using data on each model’s required parameters such as temperature, pressure, cloud height, cloud occurrence and liquid water content of clouds. The station’s cloud cover statistics, namely average amount of cloud, cloud base height, and frequency of occurrence were computed from extracted cloud data to obtain their monthly and seasonal variations. The results show that minimum attenuation values were predicted by both the Gun and East and the ITU-R models, while the Liebe and Slobin models predicted consistently maximum values of attenuation for all the cloud models tested. Cloud attenuation statistics computed for each of the models show that at 0.01% exceedance probability, the averages of the predicted cloud attenuation for uplink and downlink at Ota, ranges between 0.45 dB and 0.44 dB for Ku, 1.85 dB and 0.75 dB for Ka, and 3.50 dB and 2.50 dB for V bands. At 0.1% the averages are between 0.30 dB and 0.27 dB, 0.95 dB and 0.47 dB, 2.45 dB and 1.51 dB at Ku, ka and V bands for both uplink and downlink respectivel
Experimental evaluation of soil petrophysical attributes: Implications for sustainable agriculture
Agriculture is man’s major supplier of his needs, particularly his primary need
which is food. Soil is a major component for sustainable agriculture production needs to be
studied and understood. Soil’s characteristics determine the type of crop that would grow and
the nature of the yield of the crop. The area of study is Covenant University farmland, where
twenty soil samples from the farm were collected and petrophysical parameters such as
conductivity and salinity were analysed on each soil sample
Geoengineering site characterization for foundation integrity assessment
Inefficient near-surface characterizations prior to building construction
have largely contributed to the incessant building failures in the form of structural
defects and building collapses recently occurring in southern parts of Nigeria.
Combined geophysical and geotechnical investigations have been used to select
suitable foundation type and depth at a building construction site in part of the
Lagos Island, Nigeria. Three geoelectrical resistivity survey profiles of length 150 m
each were conducted using minimum and maximum electrode spacing of 5.0 m
and 45.0 m, respectively. Boring, in-situ geomaterials samplings, cone penetrating
tests, standard penetrometer tests and laboratory tests were among the geotechnical
investigations carried out in accordance with the British standard code of
practice. The geoelectrical resistivity imaging results provide the lateral and spatial
spread of the geoelectrical units stratification within the study area, their clay and
water contents. The results of the laboratory and geotechnical tests also reveal
the subsoils lithologic units, their compressibility and shear strengths. A deeper piletype
foundation on a more competent stable subsoil stratum at the depth greater
than 13 m is recommended for the proposed buildings in the study area so as to
effectively transmit their loads
Geospatial distribution of heavy metal contamination in Ewekoro Limestone, SW Nigeria
Limestone exploration has numerous advantage to the nation’s economy. However,
major anthropogenic activities such as mining of such mineral deposits causes environmental
contamination due to heavy metals pollution.The presence of heavy metals such as lead,
cadmium, mercury and arsenic can interfere with the biochemical pathways by interaction with
enzymes and proteins. They equally have the capacity to alter the DNA repair mechanism and
act as the inducers of carcinogenesis. The focus of the research is therefore to detect the extent
of heavy metals contaminations within the sampled Ewekoro limestone, southwestern Nigeria
and to ascertain the risks they posed to the quarry workers, miners and the people residing in
the study area
Mechanical and opto-electrical response of embedded smart composite coating produced via electrodeposition technique for embedded system in defence application
The emergence of nanocomposite particulate with the increasing demand for opto-electrical properties
for defence application has necessitated this study. In this work, an attempt was made to develop Zn-
CeO2/Zn-CeO2-Al2SiO5 thin film composite on A356 mild steel using electrodeposition technique. The
developed coating was attained in 2 V for 10 min at a constant current density of 1.5 A/cm2 and pH of 4.5.
The mass concentration of Al2SiO5 was varied, ranging from 0 to 15 g. The composite coatings were
characterized using Scanning electron microscope equipped with energy dispersive spectrometer (SEM/
EDS). The corroding properties of the coated and uncoated sample were examined through potentiodynamic
polarization technique via Autolab PGSTAT 101 Metrohm potentiostat/galvanostat with NOVA
software of version 2.1.2 in 3.65% NaCl. The electrical characterization was carried out using voltageammeter
meter and Keithley 2400 series source meter application tester. The opto-electrical investigation was done using a solar simulator with maximum intensity of 1000 W/m2 under an air mass of 1.5 at a working intensity of 750 W/m2. The outcome of various test and characterizations revealed that the electrodeposited Zn-CeO2/Zn-CeO2-Al2SiO5 possessed good stability, improved microstructural qualities, better electrical conductivity and outstanding corrosion resistance
Task Sharing and Shifting to Provide Pathology Diagnostic Services: The Kenya Fine-Needle Aspiration Biopsy Cytology and Bone Marrow Aspiration and Trephine Biopsy Training Program
Purpose: Fine-needle aspiration biopsy (FNAB) cytology is a simple, inexpensive, and accurate diagnostic test for benign, infectious, and malignant lesions of the breast, thyroid, lymph nodes, and other organs. Similarly, bone marrow aspiration and trephine (BMAT) biopsy procedures are relatively simple and inexpensive techniques that are important for diagnosing and monitoring many hematologic diseases including leukemias and lymphomas. However, the scarcity of pathologists in Kenya limits patient access to these simple diagnostic tests. We describe a task sharing and shifting program that sought to improve the provision of FNABs and BMAT biopsies in tertiary public hospitals in Kenya.
Methods: Between January 2016 and February 2017, we trained pathologists, pathology residents, and technologists from the University of Nairobi and Aga Khan University Hospital, Nairobi, in FNAB and BMAT biopsies, who in turn trained pathologists, medical officers (MO), clinical officers (CO), and technologists at five tertiary public hospitals. The program involved curriculum development, training workshops, the establishment of new and strengthening existing FNAB and BMAT biopsy clinics, interim site visits, audits, and stakeholder workshops.
Results: Fifty-one medical personnel at the tertiary hospitals were trained. The FNAB numbers increased by 41% to 1,681, with 139 malignant diagnoses (7.1%). BMAT biopsy numbers increased by 268% to 140, with 34 malignant cases. Between 60% and 100% of the FNAB and BMAT biopsy procedures were performed by MO and CO over the project period. One new FNAB and two new BMAT biopsy clinics were established.
Conclusion: This project demonstrates a successful model of task sharing and shifting from specialist pathologists to MO and CO that improved access to important FNAB and BMAT biopsy services in a low-resource setting