Paulinus Ugwuoke - Academia.edu (original) (raw)

Papers by Paulinus Ugwuoke

Electrochimica Acta, 2014

Polyanine and its nanocomposite WO 3 /PANI films were deposited on Fluorine doped tin oxide (FTO)... more Polyanine and its nanocomposite WO 3 /PANI films were deposited on Fluorine doped tin oxide (FTO) glass slides by simple Chemical Bath Deposition Method. The morphology and crystalline structure of the composite film was studied using Atomic force (AFM) and Scanning Electron Microscopy, while the electrochemical capacitive properties were determined using Cyclic Voltammetry (CV), chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS). The WO 3 / PANI nano-composite exhibited multiple colors (electrochromism) during the CV scans, from brownish green to transparent to light green then back to brownish green. Surprisingly, the integration of the PANI with the WO 3 led to synergistic performance of nanohybrid wherein a true electrochemical double layer capacitor was obtained. Also, interestingly and unlike literature reports, the CBD method led to excellent capacitance retention (> 98%) of the PANI even at 1000 continuous cycles. This work demonstrates that simple CBD can be used to get WO 3 / PANI films that give good electrochromism and pseudocapacitance comparable to the ones obtained by other methods. Hence the obtained nanocomposite film of WO 3 / PANI can be a promising material for electrochromic and energy storage applications.

The successful exploitation of groundwater requires a proper understanding of the hydrogeological... more The successful exploitation of groundwater requires a proper understanding of the hydrogeological characteristics of the sub-surface aquifers found within the basement complex. This can be carried out using various geophysical survey methods. Groundwater occurs in the joints, fissures, fractures, shear zones and weathered overburden of un-weathered rocks. Therefore effective groundwater development requires careful geophysical analysis and interpretation of data. The use of vertical electrical sounding (VES) for groundwater (hydrogeological) exploration is popular in the basement complex rocks and sedimentary basins. This study was aimed at analysing the hydro geological characteristics such as bedrock depth, lithological units and degree of fracturing and drilling location of groundwater in the basement complex / terrain of Garki, Kurudu, Dei-Dei and Kubwa areas of Abuja, North central Nigeria using Resistivity Method. Finally, the results indicate that the choice of geophysical su...

Monkey pox epidemic in Nigeria was greeted with fear as Social workers and other health experts w... more Monkey pox epidemic in Nigeria was greeted with fear as Social workers and other health experts were faced with differing health and socio-economic challenges emanating from the epidemic. The government was not poised to confront the outbreak on the onset, which resulted to panic, mystification and destabilization of community life/activities. The dominant reliance of this paper is to have an overview of Monkey pox outbreak in Nigeria and the place of social work practice intervention. The study used descriptive research design and thus, secondary data was employed. Participant observational method was also deployed in data collection. The result of the study showed that the outbreak of Monkey pox in Nigeria was characterized by panic and destabilization of socio-religious, economic and educational activities. The study also depicts that panic and perplexity that characterized the epidemic was worsened by the belief of some people that Monkey pox was a conspiracy and biological weap...

International Journal of Physical Research, Oct 10, 2017

This study assesses the wind-energyresources in Nigeria by reviewing the existing literature on t... more This study assesses the wind-energyresources in Nigeria by reviewing the existing literature on the subject matter, and also evaluates the wind potential in six locations in the northwest region of the country. Twenty-two years' (1984-2005) wind speed data obtained from the Nigerian Meteorological Agencies (NIMET) were used in this study.Weibull two-parameter and other statistical models were employed in this analysis. Wind speed distribution across Nigeria shows that some locations in the northern part of the country are endowed with higher wind potential than others in the southern part of the country. Moreover, assessment of the wind-energy resources in the study locations reveals that wind energy potential in the region is lowest in Yelwa and highest in Kano; WPD varies from 28.30 Wm-2 to 483.72Wm-2 at 10 m AGL, 45.33 Wm-2 to 775.19 Wm-2 at 30 m AGL and 56.43 Wm-2 to 964.77 Wm-2 at 50 m AGL.Thus Kano, Sokoto and Katsina are suitable for large-scale wind power generation, while Gusau is suitable for small-scale wind power generation; whereas Yelwa and Kaduna may not be suitable for wind power production because of their poor wind potential.

International Journal of Physical Research

There is need to always obtain the realistic outdoor performance variables of Photovoltaic (PV) m... more There is need to always obtain the realistic outdoor performance variables of Photovoltaic (PV) module in a location for efficient PV power system sizing and design. Outdoor performance evaluation was carried out on three types of commercially available silicon PV modules rated 10 W each, using CR1000 software-based Data Acquisition System (DAS). The PV modules under test and meteorological sensors were installed on a metal support structure at the same test plane.The data monitoring was from 08.00 to 18.00 hours each day continuously for a period of one year, from December 2014 to November 2015. Maximum values of module efficiencies of 5.86% and 10.91% for the monocrystalline and polycrystalline modules were respectively recorded at irradiance of 375 W/m2, while the amorphous efficiency peaked at 3.61 % with irradiance of 536.5 W/m2. At 1000 W/m2 the efficiencies reduced to 3.30 %, 6.20 % and 2.25 % as against manufacturer’s specifications of 46 %, 48 % and 33 % for the monocrystal...

Modeling and prediction of wind characteristics are essential design inputs in the development of... more Modeling and prediction of wind characteristics are essential design inputs in the development of wind power systems for different locations. In this paper, the daily wind data for Enugu (6.3 0 N; 7.3 0 E; 450m), Nigeria, over a period of 13 years (1995-2007), is modeled in terms of the Weibull distribution function, in order to predict wind energy potential of the location. The daily, monthly, and annual wind speed probability density distributions at 10m meteorological height are modeled and the mean wind speed, skew, shape-and scale factors are determined with values of 2.5 ± 0.3m/s,-0.46, 2.21 and 4.31m/s respectively. The results suggest that while the wind speed is more concentrated at higher values above the mean, the distribution for Enugu departs significantly from the standard Raleigh distribution, with error of 10.5%. The coefficient of determination of the model is 0.74. Further statistics suggest that the model can be used, with acceptable accuracy, for prediction of wind energy output needed for preliminary design assessment of wind machines for the location.

Weibull distribution is often invoked to interpret and predict wind characteristics needed for ef... more Weibull distribution is often invoked to interpret and predict wind characteristics needed for effective design of wind power systems for different locations. In this paper, daily average wind data for Enugu (6.4°N; 7.5°E), Onitsha (6.8°N; 6.1°E) and Owerri (5.5°N; 7.0°E) over a 25-year period is modeled in terms of the Weibull distribution in order to accurately predict wind potentials for the locations. The monthly and annual wind speed probability density distributions at 10 m meteorological height were analyzed and the Weibull shape and scale factors were empirically determined for the locations. The predicted and measured wind speed probability density distributions of the locations are compared and the accuracy of the model determined for each location using Pearson product moment correlation coefficient (r) and root-mean-square error (ξ). We find r and ξ to be 0.64, 1.40, 0.67, 1.17 and 0.93, 1.55, respectively, for Enugu, Onitsha and Owerri. The results suggest that the model can be used, with acceptable accuracy, for predicting wind energy output needed for preliminary design assessment of wind machines for the locations.

The effects of seasonal variation and angle of inclination on the performances of photovoltaic pa... more The effects of seasonal variation and angle of inclination on the performances of photovoltaic panels in south eastern Nigeria are presented. Three photovoltaic panels, each with a rated capacity of 60 W, were used for the study in each of the locations considered. Three installation positions considered are: horizontal, an angle equal to the local latitude of location and an angle 5º greater than the local latitude of location. Power output from these panels was measured at fixed time interval from dawn to dusk for 12 months. Results obtained show an average performance of 25-30 W representing about 42-50% of the panels rated capacity. Furthermore, the horizontally installed panels, on the average, presented better performance than the others angles. Thus utilization of photovoltaic panels for power generation in the region considered should be limited to lighting applications and applications within the same power requirement range. Also for overall best performance, they should b...

The hourly and monthly average global and diffuse solar radiation on horizontal surfaces in Nsukk... more The hourly and monthly average global and diffuse solar radiation on horizontal surfaces in Nsukka, a tropical climate on Lat. 6 0 52' N, Long. 7 0 24' E and 397 metres above sea level, were critically evaluated for each month of the year, starting from November 2009 to October 2010. For each month, the hourly average global and diffuse irradiance obtained were correlated with local time of the day, using second degree polynomials, while the monthly average values were correlated with the months of the year, using third degree polynomials. These correlations were performed to facilitate easy prediction of global and diffuse irradiance at any time and month of the year in Nsukka. The maximum hourly average global irradiance of 773 W/m 2 was observed at 12.00 noon for the month of January 2010, while the minimum hourly average value of 426 W/m 2 was observed at 2.00 pm for the month of August 2010. The monthly average global radiation varied from 243 W/m 2 for the month of Aug...

Volume 6: Energy, Parts A and B, 2012

ABSTRACT The performance evaluation of a developed batch reactor using beniseed oil, fresh vegeta... more ABSTRACT The performance evaluation of a developed batch reactor using beniseed oil, fresh vegetable oil, and waste vegetable oil is presented. The transesterification process was used on samples of each feedstock at different reaction temperature and time while methanol and sodium hydroxide were used as the reagent and catalyst respectively. Optimum yield obtained at 55°C and 50 minutes gave the value of 1.65 litres of biodiesel for beniseed, 1.97 litres of biodiesel for fresh vegetable palm oil and 1.81 litres of biodiesel for waste vegetable palm oil. The yield of the by product (Glycerol) was maximum at the reaction time and temperature of 70 minutes and 60°C respectively. Characterization test results showed that the produced biodiesel has similar fuel properties with the conventional diesel and agrees with the ASTM standards for biodiesel. The outcome shows that the various feedstock are good sources for biodiesel production using the developed batch reactor.

International Journal of Renewable Energy Technology, 2013

The development and measured performance of a batch reactor for biodiesel production from fresh a... more The development and measured performance of a batch reactor for biodiesel production from fresh and waste vegetable oils as feedstock is presented. A biodiesel batch reactor was fabricated using locally sourced materials. Three different transesterification reactions were performed on the feedstocks using the fabricated reactor. The reaction temperature and time were varied for the fresh and waste vegetable oils to determine the biodiesel yield. The yield of the biodiesel under these reaction conditions was at its maximum at the standard reaction temperature and time of 55°C and 50 minutes respectively, while the yield was least at a reaction temperature of 60°C. The yield of the by product (glycerol) was maximum at the reaction time and temperature of 70 minutes and 55°C respectively. The colour of the biodiesel from fresh vegetable oil was the clearest while that from waste vegetable oil 2 (WVO 2) was the cloudiest. Characterisation test results proved that the produced biodiesel has similar fuel properties with the conventional diesel and agrees with the ASTM standards for biodiesel. The outcomes of this work showed that biodiesel can be produced from various vegetable oils using the developed batch reactor.

Applied Thermal Engineering, 2007

A study aimed at a Transient analysis and performance prediction of passive cooling of a building... more A study aimed at a Transient analysis and performance prediction of passive cooling of a building using long wave nocturnal radiation in Owerri, Nigeria are presented. The system modeled consists of the room of a building with a radiator panel attached to its roof, water storage tank located inside the room, pump to circulate water through the radiator panel at night and through a heat exchanger in the room during the day. The mathematical model is based on the thermal radiation properties of the local atmosphere, the heat exchange equations of the radiator panel with the sky during the night and the equations incorporating the relevant heat transfers within the space to be cooled during the day. The resulting equations were transformed into explicit finite difference forms for easy implementation on a personal computer in MATLAB language. This numerical model permits the evaluation of the rate of heat removal from the water storage tank through the radiator panel surface area, Q wt,out , temperature depression between the ambient and room temperatures (T amb-T rm) and total heat gained by water in the storage tank from the space to be cooled through the action of the convector during the day, Q wt,in. The resulting rate of heat removal from the radiator gave a value of 57.6 W/m 2 , temperature depression was predicted to within 1-1.5ºC and the rate of heat gain by the storage water was 60 W/m 2. A sensitivity analysis of the system parameters to ±25% of the base case input values was carried out and the results given as a percentage variation of the above system performance parameters showed consistency to the base case results. An optimal scheme for the modeled 3.0×3.0×2.5 m 3 room showed a radiator area of 18.2 m 2 , a convector area of 28.62 m 2 and a tank volume of 1.57 m 3 .These results show that passive nocturnal cooling technique is a promising solution to the cooling needs for preservation of food and other agricultural produce. It is also useful in small office space cooling. Thus the model developed is undoubtedly a useful design tool for the development of passive cooling systems that can reduce considerably the huge cooling cost requirements of mechanical air conditioning systems.

Room temperature deposition of PVP capped nanostructured NiO/Ni(OH) 2 thin film, the morphologica... more Room temperature deposition of PVP capped nanostructured NiO/Ni(OH) 2 thin film, the morphological and optical characterizations by solution growth technique are reported. The nanostructured thin films which were deposited on optical glass substrates were annealed at different temperatures and then subjected to structural, morphological and optical characterizations. X-ray diffraction measurements of the films revealed that higher temperatures during the thermal treatment enhanced the crystallinity of the thin films. The SEM surface micrographs show non-interconnected uniformly deposited fibre-like structures with approximate lengths between 400 and 1200 nm. The optical band gap energy roughly decreased from about 2.7 eV to about 2.2 eV with thermal treatment. The absorbance of the thin films annealed at 300 and 400 • C was as high as 90% in the visible region of the electromagnetic spectrum. These materials could be useful in solar thermal conversion processes.

Polyanine and its nanocomposite WO 3 /PANI films were deposited on Fluorine doped tin oxide (FTO)... more Polyanine and its nanocomposite WO 3 /PANI films were deposited on Fluorine doped tin oxide (FTO) glass slides by simple Chemical Bath Deposition Method. The morphology and crystalline structure of the composite film was studied using Atomic force (AFM) and Scanning Electron Microscopy, while the electrochemical capacitive properties were determined using Cyclic Voltammetry (CV), chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS). The WO 3 / PANI nano-composite exhibited multiple colors (electrochromism) during the CV scans, from brownish green to transparent to light green then back to brownish green. Surprisingly, the integration of the PANI with the WO 3 led to synergistic performance of nanohybrid wherein a true electrochemical double layer capacitor was obtained. Also, interestingly and unlike literature reports, the CBD method led to excellent capacitance retention (> 98%) of the PANI even at 1000 continuous cycles. This work demonstrates that simple CBD can be used to get WO 3 / PANI films that give good electrochromism and pseudocapacitance comparable to the ones obtained by other methods. Hence the obtained nanocomposite film of WO 3 / PANI can be a promising material for electrochromic and energy storage applications.

Study on dye-sensitized solar cells (DSSCs) with jathropha curcas and citrus aurantium leaf extra... more Study on dye-sensitized solar cells (DSSCs) with jathropha curcas and citrus aurantium leaf extracts as sensitizers is reported in this paper. DSSCs were assembled by using natural dyes extracted from jathropha curcas and citrus aurantium leaves as sensitizers and compared with that of ruthenium dye. TiO 2 films were prepared on FTO glass using the sol-gel process, the chemical bath deposition method and the slot coating of P-25 Degussa TiO 2 powder. The chemical, structural, morphology and optical properties of theTiO 2 were investigated using energy Dispersive Spectrum EDS, X-ray diffraction XRD, UV-Visible-Infrared spectroscopy and Scanning Electron Microscopy SEM. The slot coated TiO 2 with jathropha leaf dye extract showed the highest overall efficiency of 1.26% with open circuit voltage of 350mv, short circuit current of 65.5 µA and a fill factor of 0.55.

Advances in Materials Science and Engineering, 2013

Silver oxide thin films were deposited on glass substrates at a temperature of 50°C by chemical b... more Silver oxide thin films were deposited on glass substrates at a temperature of 50°C by chemical bath deposition technique under different deposition times using pure AgNO3precursor and triethanolamine as the complexing agent. The chemical analysis based on EDX technique shows the presence of Ag and O at the appropriate energy levels. The morphological features obtained from SEM showed that the AgxO structures varied as the deposition time changes. The X-ray diffraction showed the peaks of Ag2O and AgO in the structure. The direct band gap and the refractive index increased as the deposition time increased and was in the range of 1.64–1.95 eV and 1.02–2.07, respectively. The values of the band gap and refractive index obtained indicate possible applications in photovoltaic and photothermal systems.

Electrochimica Acta, 2014

Polyanine and its nanocomposite WO 3 /PANI films were deposited on Fluorine doped tin oxide (FTO)... more Polyanine and its nanocomposite WO 3 /PANI films were deposited on Fluorine doped tin oxide (FTO) glass slides by simple Chemical Bath Deposition Method. The morphology and crystalline structure of the composite film was studied using Atomic force (AFM) and Scanning Electron Microscopy, while the electrochemical capacitive properties were determined using Cyclic Voltammetry (CV), chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS). The WO 3 / PANI nano-composite exhibited multiple colors (electrochromism) during the CV scans, from brownish green to transparent to light green then back to brownish green. Surprisingly, the integration of the PANI with the WO 3 led to synergistic performance of nanohybrid wherein a true electrochemical double layer capacitor was obtained. Also, interestingly and unlike literature reports, the CBD method led to excellent capacitance retention (> 98%) of the PANI even at 1000 continuous cycles. This work demonstrates that simple CBD can be used to get WO 3 / PANI films that give good electrochromism and pseudocapacitance comparable to the ones obtained by other methods. Hence the obtained nanocomposite film of WO 3 / PANI can be a promising material for electrochromic and energy storage applications.

The successful exploitation of groundwater requires a proper understanding of the hydrogeological... more The successful exploitation of groundwater requires a proper understanding of the hydrogeological characteristics of the sub-surface aquifers found within the basement complex. This can be carried out using various geophysical survey methods. Groundwater occurs in the joints, fissures, fractures, shear zones and weathered overburden of un-weathered rocks. Therefore effective groundwater development requires careful geophysical analysis and interpretation of data. The use of vertical electrical sounding (VES) for groundwater (hydrogeological) exploration is popular in the basement complex rocks and sedimentary basins. This study was aimed at analysing the hydro geological characteristics such as bedrock depth, lithological units and degree of fracturing and drilling location of groundwater in the basement complex / terrain of Garki, Kurudu, Dei-Dei and Kubwa areas of Abuja, North central Nigeria using Resistivity Method. Finally, the results indicate that the choice of geophysical su...

Monkey pox epidemic in Nigeria was greeted with fear as Social workers and other health experts w... more Monkey pox epidemic in Nigeria was greeted with fear as Social workers and other health experts were faced with differing health and socio-economic challenges emanating from the epidemic. The government was not poised to confront the outbreak on the onset, which resulted to panic, mystification and destabilization of community life/activities. The dominant reliance of this paper is to have an overview of Monkey pox outbreak in Nigeria and the place of social work practice intervention. The study used descriptive research design and thus, secondary data was employed. Participant observational method was also deployed in data collection. The result of the study showed that the outbreak of Monkey pox in Nigeria was characterized by panic and destabilization of socio-religious, economic and educational activities. The study also depicts that panic and perplexity that characterized the epidemic was worsened by the belief of some people that Monkey pox was a conspiracy and biological weap...

International Journal of Physical Research, Oct 10, 2017

This study assesses the wind-energyresources in Nigeria by reviewing the existing literature on t... more This study assesses the wind-energyresources in Nigeria by reviewing the existing literature on the subject matter, and also evaluates the wind potential in six locations in the northwest region of the country. Twenty-two years' (1984-2005) wind speed data obtained from the Nigerian Meteorological Agencies (NIMET) were used in this study.Weibull two-parameter and other statistical models were employed in this analysis. Wind speed distribution across Nigeria shows that some locations in the northern part of the country are endowed with higher wind potential than others in the southern part of the country. Moreover, assessment of the wind-energy resources in the study locations reveals that wind energy potential in the region is lowest in Yelwa and highest in Kano; WPD varies from 28.30 Wm-2 to 483.72Wm-2 at 10 m AGL, 45.33 Wm-2 to 775.19 Wm-2 at 30 m AGL and 56.43 Wm-2 to 964.77 Wm-2 at 50 m AGL.Thus Kano, Sokoto and Katsina are suitable for large-scale wind power generation, while Gusau is suitable for small-scale wind power generation; whereas Yelwa and Kaduna may not be suitable for wind power production because of their poor wind potential.

International Journal of Physical Research

There is need to always obtain the realistic outdoor performance variables of Photovoltaic (PV) m... more There is need to always obtain the realistic outdoor performance variables of Photovoltaic (PV) module in a location for efficient PV power system sizing and design. Outdoor performance evaluation was carried out on three types of commercially available silicon PV modules rated 10 W each, using CR1000 software-based Data Acquisition System (DAS). The PV modules under test and meteorological sensors were installed on a metal support structure at the same test plane.The data monitoring was from 08.00 to 18.00 hours each day continuously for a period of one year, from December 2014 to November 2015. Maximum values of module efficiencies of 5.86% and 10.91% for the monocrystalline and polycrystalline modules were respectively recorded at irradiance of 375 W/m2, while the amorphous efficiency peaked at 3.61 % with irradiance of 536.5 W/m2. At 1000 W/m2 the efficiencies reduced to 3.30 %, 6.20 % and 2.25 % as against manufacturer’s specifications of 46 %, 48 % and 33 % for the monocrystal...

Modeling and prediction of wind characteristics are essential design inputs in the development of... more Modeling and prediction of wind characteristics are essential design inputs in the development of wind power systems for different locations. In this paper, the daily wind data for Enugu (6.3 0 N; 7.3 0 E; 450m), Nigeria, over a period of 13 years (1995-2007), is modeled in terms of the Weibull distribution function, in order to predict wind energy potential of the location. The daily, monthly, and annual wind speed probability density distributions at 10m meteorological height are modeled and the mean wind speed, skew, shape-and scale factors are determined with values of 2.5 ± 0.3m/s,-0.46, 2.21 and 4.31m/s respectively. The results suggest that while the wind speed is more concentrated at higher values above the mean, the distribution for Enugu departs significantly from the standard Raleigh distribution, with error of 10.5%. The coefficient of determination of the model is 0.74. Further statistics suggest that the model can be used, with acceptable accuracy, for prediction of wind energy output needed for preliminary design assessment of wind machines for the location.

Weibull distribution is often invoked to interpret and predict wind characteristics needed for ef... more Weibull distribution is often invoked to interpret and predict wind characteristics needed for effective design of wind power systems for different locations. In this paper, daily average wind data for Enugu (6.4°N; 7.5°E), Onitsha (6.8°N; 6.1°E) and Owerri (5.5°N; 7.0°E) over a 25-year period is modeled in terms of the Weibull distribution in order to accurately predict wind potentials for the locations. The monthly and annual wind speed probability density distributions at 10 m meteorological height were analyzed and the Weibull shape and scale factors were empirically determined for the locations. The predicted and measured wind speed probability density distributions of the locations are compared and the accuracy of the model determined for each location using Pearson product moment correlation coefficient (r) and root-mean-square error (ξ). We find r and ξ to be 0.64, 1.40, 0.67, 1.17 and 0.93, 1.55, respectively, for Enugu, Onitsha and Owerri. The results suggest that the model can be used, with acceptable accuracy, for predicting wind energy output needed for preliminary design assessment of wind machines for the locations.

The effects of seasonal variation and angle of inclination on the performances of photovoltaic pa... more The effects of seasonal variation and angle of inclination on the performances of photovoltaic panels in south eastern Nigeria are presented. Three photovoltaic panels, each with a rated capacity of 60 W, were used for the study in each of the locations considered. Three installation positions considered are: horizontal, an angle equal to the local latitude of location and an angle 5º greater than the local latitude of location. Power output from these panels was measured at fixed time interval from dawn to dusk for 12 months. Results obtained show an average performance of 25-30 W representing about 42-50% of the panels rated capacity. Furthermore, the horizontally installed panels, on the average, presented better performance than the others angles. Thus utilization of photovoltaic panels for power generation in the region considered should be limited to lighting applications and applications within the same power requirement range. Also for overall best performance, they should b...

The hourly and monthly average global and diffuse solar radiation on horizontal surfaces in Nsukk... more The hourly and monthly average global and diffuse solar radiation on horizontal surfaces in Nsukka, a tropical climate on Lat. 6 0 52' N, Long. 7 0 24' E and 397 metres above sea level, were critically evaluated for each month of the year, starting from November 2009 to October 2010. For each month, the hourly average global and diffuse irradiance obtained were correlated with local time of the day, using second degree polynomials, while the monthly average values were correlated with the months of the year, using third degree polynomials. These correlations were performed to facilitate easy prediction of global and diffuse irradiance at any time and month of the year in Nsukka. The maximum hourly average global irradiance of 773 W/m 2 was observed at 12.00 noon for the month of January 2010, while the minimum hourly average value of 426 W/m 2 was observed at 2.00 pm for the month of August 2010. The monthly average global radiation varied from 243 W/m 2 for the month of Aug...

Volume 6: Energy, Parts A and B, 2012

ABSTRACT The performance evaluation of a developed batch reactor using beniseed oil, fresh vegeta... more ABSTRACT The performance evaluation of a developed batch reactor using beniseed oil, fresh vegetable oil, and waste vegetable oil is presented. The transesterification process was used on samples of each feedstock at different reaction temperature and time while methanol and sodium hydroxide were used as the reagent and catalyst respectively. Optimum yield obtained at 55°C and 50 minutes gave the value of 1.65 litres of biodiesel for beniseed, 1.97 litres of biodiesel for fresh vegetable palm oil and 1.81 litres of biodiesel for waste vegetable palm oil. The yield of the by product (Glycerol) was maximum at the reaction time and temperature of 70 minutes and 60°C respectively. Characterization test results showed that the produced biodiesel has similar fuel properties with the conventional diesel and agrees with the ASTM standards for biodiesel. The outcome shows that the various feedstock are good sources for biodiesel production using the developed batch reactor.

International Journal of Renewable Energy Technology, 2013

The development and measured performance of a batch reactor for biodiesel production from fresh a... more The development and measured performance of a batch reactor for biodiesel production from fresh and waste vegetable oils as feedstock is presented. A biodiesel batch reactor was fabricated using locally sourced materials. Three different transesterification reactions were performed on the feedstocks using the fabricated reactor. The reaction temperature and time were varied for the fresh and waste vegetable oils to determine the biodiesel yield. The yield of the biodiesel under these reaction conditions was at its maximum at the standard reaction temperature and time of 55°C and 50 minutes respectively, while the yield was least at a reaction temperature of 60°C. The yield of the by product (glycerol) was maximum at the reaction time and temperature of 70 minutes and 55°C respectively. The colour of the biodiesel from fresh vegetable oil was the clearest while that from waste vegetable oil 2 (WVO 2) was the cloudiest. Characterisation test results proved that the produced biodiesel has similar fuel properties with the conventional diesel and agrees with the ASTM standards for biodiesel. The outcomes of this work showed that biodiesel can be produced from various vegetable oils using the developed batch reactor.

Applied Thermal Engineering, 2007

A study aimed at a Transient analysis and performance prediction of passive cooling of a building... more A study aimed at a Transient analysis and performance prediction of passive cooling of a building using long wave nocturnal radiation in Owerri, Nigeria are presented. The system modeled consists of the room of a building with a radiator panel attached to its roof, water storage tank located inside the room, pump to circulate water through the radiator panel at night and through a heat exchanger in the room during the day. The mathematical model is based on the thermal radiation properties of the local atmosphere, the heat exchange equations of the radiator panel with the sky during the night and the equations incorporating the relevant heat transfers within the space to be cooled during the day. The resulting equations were transformed into explicit finite difference forms for easy implementation on a personal computer in MATLAB language. This numerical model permits the evaluation of the rate of heat removal from the water storage tank through the radiator panel surface area, Q wt,out , temperature depression between the ambient and room temperatures (T amb-T rm) and total heat gained by water in the storage tank from the space to be cooled through the action of the convector during the day, Q wt,in. The resulting rate of heat removal from the radiator gave a value of 57.6 W/m 2 , temperature depression was predicted to within 1-1.5ºC and the rate of heat gain by the storage water was 60 W/m 2. A sensitivity analysis of the system parameters to ±25% of the base case input values was carried out and the results given as a percentage variation of the above system performance parameters showed consistency to the base case results. An optimal scheme for the modeled 3.0×3.0×2.5 m 3 room showed a radiator area of 18.2 m 2 , a convector area of 28.62 m 2 and a tank volume of 1.57 m 3 .These results show that passive nocturnal cooling technique is a promising solution to the cooling needs for preservation of food and other agricultural produce. It is also useful in small office space cooling. Thus the model developed is undoubtedly a useful design tool for the development of passive cooling systems that can reduce considerably the huge cooling cost requirements of mechanical air conditioning systems.

Room temperature deposition of PVP capped nanostructured NiO/Ni(OH) 2 thin film, the morphologica... more Room temperature deposition of PVP capped nanostructured NiO/Ni(OH) 2 thin film, the morphological and optical characterizations by solution growth technique are reported. The nanostructured thin films which were deposited on optical glass substrates were annealed at different temperatures and then subjected to structural, morphological and optical characterizations. X-ray diffraction measurements of the films revealed that higher temperatures during the thermal treatment enhanced the crystallinity of the thin films. The SEM surface micrographs show non-interconnected uniformly deposited fibre-like structures with approximate lengths between 400 and 1200 nm. The optical band gap energy roughly decreased from about 2.7 eV to about 2.2 eV with thermal treatment. The absorbance of the thin films annealed at 300 and 400 • C was as high as 90% in the visible region of the electromagnetic spectrum. These materials could be useful in solar thermal conversion processes.

Polyanine and its nanocomposite WO 3 /PANI films were deposited on Fluorine doped tin oxide (FTO)... more Polyanine and its nanocomposite WO 3 /PANI films were deposited on Fluorine doped tin oxide (FTO) glass slides by simple Chemical Bath Deposition Method. The morphology and crystalline structure of the composite film was studied using Atomic force (AFM) and Scanning Electron Microscopy, while the electrochemical capacitive properties were determined using Cyclic Voltammetry (CV), chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS). The WO 3 / PANI nano-composite exhibited multiple colors (electrochromism) during the CV scans, from brownish green to transparent to light green then back to brownish green. Surprisingly, the integration of the PANI with the WO 3 led to synergistic performance of nanohybrid wherein a true electrochemical double layer capacitor was obtained. Also, interestingly and unlike literature reports, the CBD method led to excellent capacitance retention (> 98%) of the PANI even at 1000 continuous cycles. This work demonstrates that simple CBD can be used to get WO 3 / PANI films that give good electrochromism and pseudocapacitance comparable to the ones obtained by other methods. Hence the obtained nanocomposite film of WO 3 / PANI can be a promising material for electrochromic and energy storage applications.

Study on dye-sensitized solar cells (DSSCs) with jathropha curcas and citrus aurantium leaf extra... more Study on dye-sensitized solar cells (DSSCs) with jathropha curcas and citrus aurantium leaf extracts as sensitizers is reported in this paper. DSSCs were assembled by using natural dyes extracted from jathropha curcas and citrus aurantium leaves as sensitizers and compared with that of ruthenium dye. TiO 2 films were prepared on FTO glass using the sol-gel process, the chemical bath deposition method and the slot coating of P-25 Degussa TiO 2 powder. The chemical, structural, morphology and optical properties of theTiO 2 were investigated using energy Dispersive Spectrum EDS, X-ray diffraction XRD, UV-Visible-Infrared spectroscopy and Scanning Electron Microscopy SEM. The slot coated TiO 2 with jathropha leaf dye extract showed the highest overall efficiency of 1.26% with open circuit voltage of 350mv, short circuit current of 65.5 µA and a fill factor of 0.55.

Advances in Materials Science and Engineering, 2013

Silver oxide thin films were deposited on glass substrates at a temperature of 50°C by chemical b... more Silver oxide thin films were deposited on glass substrates at a temperature of 50°C by chemical bath deposition technique under different deposition times using pure AgNO3precursor and triethanolamine as the complexing agent. The chemical analysis based on EDX technique shows the presence of Ag and O at the appropriate energy levels. The morphological features obtained from SEM showed that the AgxO structures varied as the deposition time changes. The X-ray diffraction showed the peaks of Ag2O and AgO in the structure. The direct band gap and the refractive index increased as the deposition time increased and was in the range of 1.64–1.95 eV and 1.02–2.07, respectively. The values of the band gap and refractive index obtained indicate possible applications in photovoltaic and photothermal systems.