The potential occurrence of certain illnesses can be easily diagnosed through measurements of some health indicators. One of such parameters is the Body Mass Index (BMI). BMI is simply the ratio of mass (kg) of a body to the square of its height (m2). This research presents the design and construction of an automated BMI measurement machine for medical purposes. It consists of three major units: the weighing unit (5 – 200 kg); height-measuring unit (0.02 – 2 m) and the processing unit. The weighing unit is made up of load button cell and load cell amplifier while the height-measuring unit consists of ultrasonic sensor. The analog differential output voltage from load cell is connected to arduino microcontroller via a Programmable Gain Amplifier (PGA) integrated with Analogue-to-Digital Converter (ADC). The two units are connected to an open source arduino uno which computes mass-to-body ratio and sends the output results (mass, height and BMI) to the liquid crystal display (LCD). The weighing system was calibrated against a precision digital weighing system and it gave a correlation of 0.99. The height measurement was also compared with manual height measurement using a tape rule which gave a correlation of 0.97. The developed Instrument is cost effective and has high positive correlation with the standards (weighing scale and tape rule), it is therefore recommended for the measurement of weight, height and BMI. Keywords— load button cell, load cell amplifier, ultrasonic, body mass index, arduino uno

Variation of soil temperature and soil heat flux measurements from a locally fabricated and calibrated device were analyzed and compared with a standard device. The soil heat flux consists of two-disc aluminum plates, dielectric material and two thermocouples such that each thermocouple was sandwiched between the aluminum plates and one side of the dielectric material. The sizes of the aluminum plates and the dielectric material were 32 mm in diameter and their thickness is 2.5 mm. Differential temperature between two thermocouples attached to two aluminum plates separated by a thermal insulator was used to measure the soil heat flux values. The thermocouples amplifier module AD8495 and then combined with a 16-bit Analog to Digital Converter (ADS1115) for a good measurement resolution was employed for the signal conditioning. A semiconductor sensor DS18B20 was used to measure the soil temperature. The microSD shield was included for storing data and DS3232, a Real Time Clock (RTC) module for timekeeping. Arduino mega 2560 microcontroller was used to coordinate the whole active and display the activities on LCD. The soil heat flux sensor was calibrated using the principle of thermal conduction over the surface area by heating with a known heat source. The thermal conductivity of heat flux is given by 3.3407 (WV-1m-1) from the empirical deduction. The temperature sensing unit was checked for accuracy by inserting it inside a calorimeter with the mercury-in-glass thermometer and the correlation obtained was 0.92. The soil heat flux and temperature sensing unit were compared with that of standard Campbell device. The correlation obtained for soil heat flux and temperature were 0.89 and 0.95 respectively. The result obtained when installed at the Redeemer's University, Ede, Nigeria, the variation of soil heat flux and temperature when placed at the same level of 10 cm into the soil gave the same value. The maximum peak of heat flux density usually occurs at about 13:00 pm to 15:00 pm with values around 260 W/m2 at 10 cm. The logging interval can be preset to any rate from 30 seconds and above.

The Data Acquisition System (DAS) is an important equipment in measurement systems especially in weather monitoring and also very crucial in many areas such as agricultural, communication, transportation, sport and industrial processes. This work proposes a weather monitoring system based on an Arduino Mega 2560 microcontroller board. The microcontroller has the ability to monitor, record and display the information of atmospheric sensor parameters connected to its analogue and digital pins. The outputs of analogue sensors are connected to the microcontroller through separate ADC for sampling. An LCD attached to the microcontroller displays the measured parameters. For analysis, the data is stored in excel format and can be copied directly from microSD card. The DAS was tested and examined through intensive experimental work. The tables and plots obtained from the experiment for standardizing the sensors, it is clear that there is a close conformity between the data collected by the developed system and the existing standard systems. The need for extra cost baud rate and expensive third-party computer software for interfacing to download data from the logger have been eliminated. There is no need of internet for any linking or configuration. It is evident that the DAS is of better choice in terms of cost and maintenance. The system will be helpful in monitoring and recording of atmospheric parameters. HIGHLIGHTS Only a few weather monitoring stations in Nigeria are functioning as a result of the high cost, maintenance and repair services of imported DAS systems. Also, imported DAS devices are often not suitable for the tropical environment Other problems include: proprietary software that lacks flexibility, the necessity for third-party software to extract data and difficulties in getting usable parts and unexpected changes in production designs Developed DAS device offers a higher resolution compared to existing devices Low-cost and flexible meteorological DAS system with ease of installation Convenience in deployment for weather data acquisition and research purposes in relevant fields GRAPHICAL ABSTRACT

The steam turbine is a prime mover that converts kinetic energy in steam into rotational mechanical energy through the impact or reaction of the steam against the blades. The aim of this study is to design a steam turbine for a small scale steam power plant with target of producing electricity. The turbine is driven by the heat energy from palm kernel shells as a renewable energy source obtained at a lower or no cost. The study was concentrated on design of turbine elements and its validation using computer packages. Specifically, the microturbine design was limited to design, modeling, simulation and analysis of the rotor, blades and nozzle under the palm kernel shell as fuel for the micro power plant. In blade design, stress failures, efficiency and blade angle parameters were considered. In casing volume design, the overall heat transfer and mean temperature, and different concepts were applied. The thermal distribution on stator and rotor was considered in order to determine its level of tolerance. The design software packages used for design validation were Solidworks and Comsol Multiphysics for analysis. Simulation results showed that the designed steam turbine can adequately tolerate change in stress/load, torsion/compression, temperature and speeds.

Purpose: There are many algorithms and models that are successfully utilized in controlling noises and preventing signal fading in communication networks. Signal strength enhancement studies that utilize component-based quality improvement algorithm are not common.Methodology: A signal detection algorithm was developed using the component-based sigma quality improvement flow system. The algorithm was implemented on MATLAB computer programming software.Findings: The algorithm/model was capable of filtering out noises and optimizing RF-signal detection in communication networks. The signal detection results showed super-improved signal Energy to Noise Ratio (ENR) on the balanced probability basis.Unique contribution to theory, practice and policy: Introduction of component-based sigma quality improvement algorithm is an added advantage over the traditional techniques thereby enhancing further fading reduction in communication networks