This paper presents a novel design for the top contact of thin film photovoltaic (PV) solar cells. The new top contact is formed by fabricating a 20nm thin honeycomb shaped silver mesh on top of an ultra-thin 13nm of indium tin oxide. The new top contact offers the potential to reduce the series resistance of the cell while increasing the light current via plasmonic resonance. Using the nano-bead lithography technique the honeycomb top contact was fabricated and electrically characterized. Th...
Titanium dioxide (TiO2) nanostructures (nanorods and nanoparticles) were prepared using a low-cost microwave irradiation method from a polyol medium of glycerol. Titanium glycerolate and TiO2 powders were obtained in the glycerol medium for the first time with four different power densities (240 W, 480 W, 720 W, 960 W) of irradiation using a domestic microwave oven of 2.45 GHz, to understand the impact of power on morphology tuning. The structural and morphological features of the t...
A full mechanical characterisation of three types of 3-D printed lattice cores was performed to evaluate the feasibility of using additive manufacturing (AM) of lightweight polymer-based sandwich panels for structural applications. Effects of the shape of three selected lattice structures on the compression, shear and bending strength has been experimentally investigated. The specimens tested were manufactured with an open source fused filament fabrication-based 3-D printer. These sandwich st...
Anatase TiO2 displaying dual morphologies were synthesized with a simple chemical route via a single step. A strong correlation between the dye sensitized solar cell (DSSC) device performance and the obtained dual morphologies are highlighted using relevant evidences from UV-vis and diffuse reflectance spectroscopy (DRS), Raman analysis, field emission scanning electron microscope, high resolution transmission electron microscope, current-voltage characteristics and impedance analysis. Struct...
In this work, upgraded metallurgical grade silicon (UMG-Si) wafer was used to fabricate mesoporous nanostructures, as an effective antireflection layer for solar photovoltaic cells. The length of the vertical Si nanostructure (SiNS) arrays was altered by varying the etching time period during metal assisted chemical etching (MACE) process, using a silver catalyst. The optical, structural, morphological changes and the antireflection properties of Si nanostructures formed on UMG-Siwafer were a...
Fab labs, which offer small-scale distributed digital fabrication, are forming a Green Fab Lab Network, which embraces concepts of an open source symbiotic economy and circular economy patterns. With the use of industrial 3D printers capable of fused particle fabrication/ fused granular fabrication (FPF/FGF) printing directly from waste plastic streams, green fab labs could act as defacto recycling centers for converting waste plastics into valuable products for their communities. Clear finan...
Graphene has attracted world-wide attention due to its intriguing set of properties. However, the production of graphene on the bulk scale remains a significant challenge which is limiting its uptake in applications, particularly composites. The exfoliation of graphene in solvents using ultrasonic energy is the most promising approach to-date for the large scale production of graphene flakes. The process relies on a good interaction between the graphene and the solvent used. This interac...
Etrudate characteristics of briquettes produced and effects of extrusion factors using an existing screw extruder have been investigated. The feedstock material used in the test is sawdust collected from sawmills around Ibadan metropolis. Particle distribution analysis of materials collected showed that the size varies between 6-8 mm with 10-20% powdery component (< 4 mesh) which is known to give better products. Samples of briquettes produced were used for physical characterization. Physical...
This paper presents a systematic approach to develop a wear model of Al-Cu-Mg/Palmkernel shell ash particulate composites (PKSAp) produced by double stir -castingmethod. Four factors, five levels, central composite, rotatable design matrix was usedto optimize the number of experiments. The factors considered were sliding velocity,sliding distance, normal load and mass fraction of PKSA reinforcement in the matrix.Response surface methodology (RSM) was employed to develop the mathematicalmodel....
ABSTRACT Snail shells and discarded aluminium components are of low economic values, and are often considered as environmental pollutants. Finding ways of utilizing these supposed wastes is consequently a direct way of creating wealth from wastes. Snail shell particles are known for their hardness, and thus considered as good alloying agent for aluminum based composites. ...
Abstract This study focused on the factors responsible for poor performance of senior secondary school students in mathematics in Onitsha Education Zone. The study was guided by four research questions. The study is a descriptive survey design. The targeted population consisted of senior secondary school students in Onitsha Education Zone. A total of 100 respondents were purposively selected by the researchers. The data were collected through the use of structured questionnaire after it was...
ABSTRACT The main purpose of this project is to Analyze Road Traffic Accident (RTA) data in Nigeria, taking Anambra State as a Case of Study and to find out the major causes of such accident and suggest strategies for preventing or controlling them for the benefit of road users. An Analysis of Accident data recorded between the years 2004 – 2008 has yielded the following facts: over speeding and faulty tires are the causal factors of road accidents. These are but the majo...
Abstract Physical Separation process refers to all the mineral separation techniques that are based on exploiting the differences in specific physical properties of the mineral such as specific gravity, magnetic properties, thermal and electrical conductivity. Physical separation techniques are usually preferred for economic reasons. Physical separation techniques include; •Gravity separation process •Classifiers •Magnetic separation process •Electrical separation process •Separati...
Scope of Presentation 1. Definition of light metals/alloys. 2. Examples of light metals. 3. Characteristics/properties of light metals. 4. Trends in production and applications of light alloys. 5. Production of light metals
The drive behind this research work cannot be far-fetched from the quest to precisely predict how effectively welded low carbon steel pipes will function in industrial service applications requiring subjecting them to service use at elevated temperature as a function of inferences drawn from a critical study of the corrosion behavior of these welded steel pipes in both acidic and salty environment. To this end, a particular low carbon steel pipe of known chemical composition was sectioned int...