Construction of a Self-regulating Thermoelectric Air-Cooling System

The most common method of refrigeration, a vapor compression air cooling system (VCACS), has adverse effects on both human health and the environment, including refrigerant poisoning, ozone layer depletion, and other severe consequences. This project attempts to provide an alternative method of refrigeration that can compete with the VCACS and offer a more sustainable solution. The thermoelectric air-cooling system (TACS) is one such alternative, which operates without the use of gases. In this project, we compare the TACS to the VCACS. The thermoelectric air cooler is constructed using a Peltier module as the primary component, which is placed on a heat pump to remove hot air and enable the device to reach optimal temperatures. While the temperature of the thermoelectric cooler drops at equal rate similar to that of a VCACS, it ceases moving after reaching a specific temperature. During the experiment, it was observed that the TAC can reach a mean temperature of 29.70 ℃ which is close to that of the VCAC which is 29.35 ℃. It means the TAC has equal cooling rate just as the VCAC (i.e., 0.053 ℃/min). Also, in terms of power consumption, compared to the VCAC, the TAC consumes about 62.04 W of power which makes it more energy efficient than the VCAC. Overall, the thermoelectric air cooler offers a promising alternative to the traditional VCACS method of refrigeration, without the negative influence on the environment and human health

Tropospheric attenuation on Satellite-aircraft propagation: A concise review

The attenuation time together with the Complementary Cumulative Distribution Function of attenuation values play a vital role in the design of communication systems. Passengers on-board during flight can be connected to the internet either via satellite or earthstation depending on the nature of the flight. For long distance flight, this internet connectivity is provided through satellite when the aircraft is flying at the upper troposphere. However, the satellite-aircraft link is subject to attenuation due to the troposphere. A model to characterize the channel has been proposed. In particular, a methodology for the synthesis of attenuation on aircraft-satellite is given by ITU-R P2041 recommendation. However, it has been shown that the impact of tropospheric parameters such as rainfall, cloud, gases etc. On the satellite-aircraft link at different frequencies are insignificant (i.e decreases with height) on the upper troposphere since the aircraft is flying (about 12 km) above the rain height (5 km). The findings will be useful for researchers, scientists and the aviation industries in planning, design and establishing link budget for aircraft-satellite path

Assessment of heavy metal contents in farm produce around Ewekoro and its health implications on consumers

This study was conducted to assess the risk of exposure to thirteen (13) heavy metals from food products obtained from cassava tubers grown in the limestone mining area of Ewekoro, Ogun State in Nigeria. Four (4) samples each of soil and cassava tubers were collected at three different sites for this study. The first two sample collection sites were at 150 m and 300 m from the mining site while the third or the control samples were collected at a distance of 25 km far away from the mining activities. The collected samples were analyzed by the use of Inductively Coupled Plasma-Optical Emission Spectrometry. The concentration average of Fe, Mg, Na, Ag, As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn ranged from 2.00–1284.96 to 0.0098–646.31 mg/kg for both soil and cassava tubers, respectively at site 1, which was far higher than 0.26–622.01 and 0.90–514.35 and 0.07–688.37 and 0.07–371.74 mg/kg reported in both soil and cassava tuber samples at the other 2 locations. The transfer factor from the soil to cassava tuber for Fe, Mg, Ag, As, Cd, Cu, Co, Mn and Pb were observed to be 1. The estimated average daily intake at site 1 for both adults and children were 0.46 and 1.69 mg kg− 1 bw− 1 d− 1, respectively. These values were far higher than the results noted at sites 2 and 3 for both adults and children. Similarly, the Risk Index for both adults and children at site 1 were reported to be 7.01 and 25.42, which were higher than the values noticed at the other 2 sites. Therefore, it can be concluded that although the concentrations of these heavy metals were higher than the internationally recommended standard, the EADI and RI revealed that children are at higher risk of exposure to the heavy metal contents from food products derived from cassava in the study area

Evaluation of the effect of silver nanoparticles and biopolymer on modified Nigeria bentonite rheological properties

During drilling mud preparation, large quantities of imported Bentonite clay are consumed by activities to develop petroleum and underground natural resources. In this research, locally made Bentonite clay was used, its rheological properties were investigated and compared with the stipulated America petroleum institute (API) standard values. The raw bentonite obtained in Gombe state, Nigeria, was weighed, crushed, and prepared to remove the impurities at room temperature. The cake gotten was sundried and broken into powder. The clay's swelling ability was studied using a design expert software to generate the combined ratio of 3.75g of clay, and 0.3g of sodium carbonate (Na2CO3) dispersed in a fixed volume of distilled water in a measuring cylinder for 24hours. The procedure was then repeated for other runs. The clay beneficiation was done by scaling up the optimal value obtained for both clay and Na2CO3. Beneficiated clay was impregnated with silver nanoparticles (Ag/NPs) acquired from the Department of Biology, Ladoke Akintola University of Technology. The food gum obtained from the market was peeled and pounded; the liquor extracted was sundried and reduced to a particle size of 0.12 μm. In determining the rheological properties, a viscometer (OFITE model 900 viscometer) was used. It was observed in this study that the local made Bentonite rheological properties like plastic and apparent viscosity, gel strength, and yield point were significantly improved at various temperatures of 23°C and 100°C when compared with API standard values. Similarly, the impregnation of beneficiated clay with Ag/NPs has no significant effect on the of the Gombe Bentonite clay's rheological properties

Numerical Analysis of the Measured Temporal Rainfall Rate and Rain Attenuation in a Tropical Location

Extreme weather condition is one of the major challenges observed in the troposphere due to meteorological weather parameters such as rainfall. Rainfall causes severe attenuation to satellite communication at Ku band. This paper studied the numerical relationship between the calculated rain attenuation and the observed rain rate at Ku band for the tropical station based on a 12-month data measurement. This paper aims at presenting the proportional variation between rain rate and rain attenuation in the locality of interest. A tipping bucket rain gauge is used to obtain and analyse rain rate data. One-minute signal strength measurement were obtained and analysed. The 12-month data were obtained from January till December 2015. The result shows an average rain rate of about 237.0 mm/hr, 114.0 mm/hr, 38.0 mm/hr and 3.0 mm/hr and attenuation of 4.74, 4.25, and 3.59 and 2.66 dB/km at 12.245 GHz, respectively, for 0.001 %, 0.01% and 0.1% and 1 % of the time respectively for the combined values of rain rate and rain attenuation statistics. The result indicates a corresponding direct proportionality between the rain rate and rain attenuation

Numerical Analysis of the Measured Temporal Rainfall Rate and Rain Attenuation in a Tropical Location

Extreme weather condition is one of the major challenges observed in the troposphere due to meteorological weather parameters such as rainfall. Rainfall causes severe attenuation to satellite communication at Ku band. This paper studied the numerical relationship between the calculated rain attenuation and the observed rain rate at Ku band for the tropical station based on a 12-month data measurement. This paper aims at presenting the proportional variation between rain rate and rain attenuation in the locality of interest. A tipping bucket rain gauge is used to obtain and analyse rain rate data. One-minute signal strength measurement were obtained and analysed. The 12-month data were obtained from January till December 2015. The result shows an average rain rate of about 237.0 mm/hr, 114.0 mm/hr, 38.0 mm/hr and 3.0 mm/hr and attenuation of 4.74, 4.25, and 3.59 and 2.66 dB/km at 12.245 GHz, respectively, for 0.001 %, 0.01% and 0.1% and 1 % of the time respectively for the combined values of rain rate and rain attenuation statistics. The result indicates a corresponding direct proportionality between the rain rate and rain attenuation