Briquettes from agricultural residues; an alternative clean and sustainable fuel for domestic cooking in Nasarawa State, Nigeria

In Nasarawa state, over 70% of the population are involved in subsistence farming. Varied agricultural resources are produced in millions of tons annually. Large quantity of residues is generated that are either left to rot on farmlands or disposed of by burning in open air. In many rural areas, the residues are also used in their raw form for cooking purposes which is inefficient. The disposal and use of the residues cause pollution in the environment which affects human health. Residues can provide a source of clean and renewable energy in the form of solid biofuel called briquettes through densification. Briquetting is a densification technology that converts residues with a low heating value per unit volume into high density and energy concentrated fuels. This paper offers a perspective on the potentials of agricultural residues in Nasarawa state to produce briquettes as an alternative clean and sustainable domestic cooking fuel. The paper concludes that briquettes could be economically and environmentally friendly alternative to fuelwood. The use of biomass briquettes would reduce dependence on fuelwood, environmental pollution and the amount of time spent on cooking. Adopting the briquetting technology will enhance access to clean and affordable energy in line with the 7th goal of the United Nation’s Sustainable Development Goals

Determination of ethanol concentration of ethanol/water mixture solutions with open ended coaxial method

This study presents a simple and non-destructive procedure to determine ethanol concentration of ethanol/water solution at ambient temperature based on HP85070B open ended coaxial dielectric constant measurement. The motivation for this study stems from the fact that the `true' concentration of ethanol in a `labeled' container could be `spoiled' due to hygroscopic nature of ethanol, evaporation and other factors. The dielectric constant measurements of eight samples with different molar fraction were validated with modified Cole-Cole-Debye (3CC) simulations. A 5th degree polynomial calibration equation was developed based on 3CC simulations with R2 = 0.9998 and used to estimate the `true' concentration of three ethanol samples obtained from `labeled' containers kept in laboratory. The ethanol concentrations of two of the samples were found to be much lower than what was indicated on their labels, hence, assumed spoiled

Microwave characterization of bio-composites materials based finite element and Nicholson-Ross-Weir methods

In this work, Bio-composite of oil palm empty fruit bunch fibre (OPEFB)-filler and polycaprolactone (PCL)-polymer has been prepared and characterized. The functional groups and morphology of the prepared samples were characterized by Fourier transform infrared spectroscopy (FT-IR). By using the Nicholson- Ross-Weir (NRW) mode, both of real and imaginary relative permittivity values of the samples were obtained simultaneously from the reflection and transmission coefficient measurements of the materials. Whereas, the attenuation with the field distribution at the waveguide filled with a sample were considered by using the Finite Element Method (FEM). The magnitude of the reflection and transmission (R/T) coefficients of the composite with different filler percentages were measured using rectangular waveguide in conjunction with a microwave vector network analyzer (VNA) in X-band range of frequency. The computations of the S-parameters were achieved by using the FEM technique along with NRW mode. Then, the obtained results were compared with the measured R/T coefficients. Relative error results nominated the FEM mode due to its highly accurate results than the other method

Synthesis and characterisation of nickel oxide reinforced with polycaprolactone composite for dielectric applications by controlling nickel oxide as a filler

Developing new absorbing and sheilding materials with a large band of frequency and high performance to allow the coexistence of the electronic components without the damaging electromagnetic interference (EMI) is needed. This paper is about the development of microwave-absorbing material from polycaprolactone by the addition of nickel oxide. Preparation of NiO/PCL composites to homogeneous were carried out using a Brabender Internal Mixer using the melt blend technique. These composites were characterized using Fourier transform infrared (FT-IR) spectrometry, scanning electron microscopy (SEM) as well using X-ray diffraction (XRD). Dielectric properties were obtained over a broad range of frequency of 8–12 GHz at the room temperature. It is found that the permittivity values increased via NiO filler content increments and decreased with frequency hikes. An instrument of rectangular waveguide is connected to a network analyzer (PNA) and the values of transmission (S21) and reflection (S11) parameters were measured which were also used for calculating reflection loss, microwave absorption values and the shielding properties of EMI by NiO/PCL composite at X-band frequencies. The measurement results found the material has good EMI shielding application potential as its microwave absorption has shown

Application of a monopole sensor for rapid in situ water quality assessment: theoretical analysis

This initial study proposes a rapid and cost effective in situ water quality assessment based on reflection coefficient of a 1.749 cm long bare monopole senor. The reflection coefficient of the monopole sensor in air, water and ethanol were studied from measurement and calculations of Finite Element Method (FEM). FEM was used to calculate the reflection coefficient of the sensor in water/ethanol mixture solution

The development of low cost turbidimeter using smartphone camera and image processing

In this paper, the design fabrication and development of a low-cost turbidimeter with a smartphone camera and image processing are demonstrated. The turbidimeter serves as a simple and low cost alternative to professional standard turbidimeters as well as other proposed turbidimeters presented in other studies. This turbidimeter is made from affordable and widely available materials and electronic components. The proposed turbidimeter was tested and able to determine the turbidity of Formazine samples between 0 and 100 NTU with the coefficient of determination R2= 0.982. The overall cost of this turbidimeter is only USD4.35, which is well below the cost of other proposed turbidimeter

Monopole antenna technique for determining moisture content in the Dioscorea hispida tubers

This study demonstrates the determination of moisture content in D. hispida tuber using microwave technique. A network analyzer was used to measure the reflection coefficient of a monopole antenna inserted in D. hispida tuber at different percentage of moisture content. The actual moisture content of D. hispida tuber was determined using oven drying method. The reflection coefficient measurement was performed at operating frequency between 2 MHz and 4 GHz. The best operating frequency to model the relationship between the magnitude of reflection coefficient and moisture content in the D. hispida samples was found to be 0.8 GHz. The model based on measured data of sample D with a regression value of 0.9399 and1.71% error was the most accurate model to predict moisture content in D. hispida tuber

Evaluation of hybrid briquettes from corncob and oil palm trunk bark in a domestic cooking application for rural communities in Nigeria

This study developed hybrid briquettes using corncobs and the bark of oil palm trunk (OPTB). The objective was to assess the performance of the briquettes in a cooking application as a potential fuel source for domestic utilization. Corncob was mixed with OPTB in ratios of 100:0, 75:25, 50:50, 25:75 and 0:100 by weight, and wastepaper pulp (10% by weight) was added to each mixture as the binder. The mixtures were densified manually at room temperature using a 20-tonne hydraulic piston press under a ≤7 MPa compaction pressure. The calorific value of the briquettes was determined by a bomb calorimeter, while other fuel properties were determined by proximate and ultimate analysis. The briquettes’ performance was evaluated by a water boiling test, and gaseous emission was determined and reported based carbon-dioxide equivalent (CO2e). Results showed that the volatile matter, ash content, and calorific value increased with the increase in OPTB in the ratios while fixed carbon decreased. Additionally, briquettes produced from ratios 50:50 and 25:75 were similar in values based on the total time taken to ignite briquettes and boil 1 L of water (17.54 min and 17.13 min), fuel burning rate (0.69 kg/h and 0.70 kg/h) and specific fuel consumption (0.16 kg/l and 0.15 kg/l). However, ratio 50:50 performed better in terms of thermal fuel efficiency (17.25%) and produced less ash during combustion and thus, is considered the optimum combination. Greenhouse gas emission of all briquettes ranged from 241 to 281 gCO2e. The results suggest the possibility of producing briquettes with adequate fuel properties for combustion from a blend of corncobs and OPTB. The calorific value and performance of the hybrid briquettes have confirmed and justified the use of OPTB, which have previously not been used for briquette production, thus making a novel contribution to biomass options. The study shows a means of reducing waste, energy shortages, and indoor air pollution in rural communities in Nigeria. Overall, the hybrid briquettes are sustainable, environmentally friendly and cost-efficient compared to fossil fuels

Development of an affordable soil moisture sensor system with mini-VNA Tiny and smartphone

This study attempts to develop a soil moisture measurement system with a monopole antenna sensor, mini-VNA Tiny and a mobile phone respectively. The mini-VNA Tiny is a compact vector network analyzer (VNA) with a USB connection to a smartphone or a tablet. There are 17 sets of data which have been collected from 15 different spots with varying soil moisture content. The actual moisture content on site was collected from TRIME-PICO 64/32 sensor. Upon collection, it was necessary to calibrate the resistance obtained from the mini-VNA between 1 MHz and 3 GHz. The data obtained from the study shows that the resonances of the antenna resistance shift to the left on the frequency spectrum as moisture content increases. A linear model relating the resistance and actual moisture content was developed from this study with coefficient of determination (R2) value of 0.723 at 13 MHz. This value is much less than the anticipated R2 = 0.95 for accurate measurement of soil moisture with monopole antenna at microwave frequency. This could be due to the 0.60 cm thickness of the monopole antenna which may not be suited for soil moisture measurement. Nonetheless, this study demonstrates the potential application of an inexpensive and portable mini-VNA Tiny and smartphone system for sensing applications

Investigation with gifted students in learning physics concept based on cognitive structure

Physics concept is an understanding of natural occurrence. Physics is one of the natural science subjects that involves the study of matter and motion through space and time, along with related concepts. The concepts of physics explained everything involving the environment and human relation that happened in our daily life. Physics is one of the toughest subjects. Many students have difficulty to understand the subject properly. The factor of difficulty in learning physics concept come from many aspects, which is subject matter, materials for learning, the environment in class, and teaching style. Therefore, this study aims at investigating the main factor affecting the understanding of student performance in physics subject. This study has been done by given question paper that is designed based on taxonomy bloom. The question paper consists of 10 questions divided into three stages of taxonomy bloom, which are C1 (remembering), C2 (understanding), and C3 (applying). The test has been conducted among 17 years old students in Kolej PERMATA Insan. The result of the test has been analyzed. Based on the test that has been held, the results showed that most students did not reach the minimum mark of for the three stages in taxonomy bloom mainly stage C3 questions that apply the physics concept in daily life. The results from the test showed that physic is a tough subject to be learned