RMUTL Engineering Journal

Solar battery charger by monitoring via Smartphone application

2023-01-30T12:14:27+07:00

Solar cell monitoring system using the Blynk application has some restrictions in crossing platforms for Android and iOS. Because the widget boxes of the Blynk application are limited in the energy usage to only 2,000 joules, the web dashboard also has complexity for the application. This paper proposes a solar battery charger monitoring mobile application for Android and iOS platforms with Firebase, which can operate cross-platform by using Ionic Framework. Cordova is mainly the management of Ionic Framework, which will be getting commands to form HTML, CSS, and Angular JS to each application of Android and iOS. We implement solar battery charger by using simple buck converter interfaces with Arduino board under Pulse Width Modulation to control the battery charger, and using ACS712 module and voltage divider circuit interface with Arduino to measure the current and battery's voltage while charging the battery. NodeMCU is interfaced with an Arduino module for transferring all data via WiFi to Android and iOS Smartphones. Those data will be transferred for the record on Firebase at Cloud Server. For the experimental results, the solar charger can fully charge the battery in 10-12 hours which may depend on the sun's irradiation each day. The average battery voltage after fully charged is 13.8V. On Smartphones of Android and iOS, our applications can control and display the operation correctly. In addition, the application displays the history of battery charging as well. Our research indicates that Firebase has a significant and necessary crossing platform capability on Smartphones that can operate for Android and iOS.

Development of Frequency Response Simulation Program for Filter Circuit Design

2023-03-24T08:03:02+07:00

This paper presents a simulation program that utilizes the MATLAB GUI interface to calculate part values and display frequency responses for wireless communication systems filters. The simulation supports computational theory with three circuit models: T-model, Pi-model, and K-inverter. Users have the flexibility to choose their desired filter response type, schematic, filter type, passband ripple configuration, and response order. The simulation's complex equations enable accurate element value calculation and circuit design. Additionally, users can compare frequency response graphs to facilitate on-demand analysis and design. The simulation results are in agreement with filter theory, making it an effective tool for teaching and learning the fundamentals of frequency response in wireless communication. Furthermore, the filter element values derived from the simulation can be employed in advanced circuit design.

Study of the Temperature Optical Fiber Sensor using OTDR

2023-04-25T12:52:04+07:00

This paper demonstrates the optical fiber sensor for temperature sensing using OTDR (Optical Time Domain Reflectometer) with the application of telecommunication optical fiber. OTDR measures the Rayleigh back scattering optical power signal at the part of fiber sensing for the analysis of the relationship between optical signal attenuation and the variation of temperature change. Sensor device composes of the optical fiber wrapped around the thin copper-plated cylindrical shape with diameter about 10 cm. To observe the temperature effect, hot air will be brown by the hot air blower through the cylindrical fiber sensor. OTDR signature results from the sending of the optical signal with pulse width 30 ns at wavelength 1550 nm. The experiment was carried out for a duration of 60s for each optical pulse in the temperature range of 25-130 oC. The experimental results show that the attenuation of the optical signal at the part of fiber sensor varies as the temperature changes. The proposed system expresses potential applications for a temperature sensor.

Automatic Water, Fertilizer and Insecticide Dispenser System for Rose Garden using ESP8266 and Blynk IoT Platform

2023-01-30T12:13:37+07:00

The purpose of this work is to develop an automatic water, fertilizer, insecticide dispenser system for rose garden based on timers set via a smartphone and Blynk IoT platform. With the aim to reduce manual labor and save resources, the system is able to control the water supply, fertilizer, and insecticide amount through a relay module connected to the solenoid valve. Fertilizer and pesticide mixture stored in separated tanks are dispensed into the rose garden plot of size 1m x 4.5m via PVC and PE pipes. A dropper is installed above the base of each rose plant for water and fertilizer distribution. As for dispensing of the pesticide, five spray nozzles are attached to the pipe at the top of the plot. To monitor the condition of the plot, soil moisture, air humidity and temperature sensors are installed and the sensor data are collected and displayed on the application. All control and data transmission are handled by an ESP8266 module in conjunction with a Blynk IoT platform. In addition, the system is able to send alert messages about the solenoid valve operations via Line Notify. The proposed control system and application were deployed and tested at Ponpimol Rose Garden in Chiang Mai, Thailand for a period of one month. Throughout this period, the system was able to continuously operate without any errors or downtime, and all LINE notifications were correctly sent. The target rose plot carried 45 rose plants which were between 30 – 50 cm in height. The amount of water, fertilizer, and insecticide dispensed at each instance were 42.75 l, 453 ml, 2.26 l, respectively. According to the cost analysis, the proposed system can help reduce the labor cost by 52%, and after considering the cost of equipment and installation, the break-even point is around 94 days.

Using Cow Feces as a Concrete Mix as a Guideline For the Production of Interlocking Bricks

2022-11-25T14:27:44+07:00

This research aims to use cow feces from dairy farms as an aggregate of interlocking bricks. The cow feces were obtained from the separator process. The dry cow feces passing sieve No 4 were among the ingredients in concrete which serves as a guideline in producing interlocking bricks as community products. The mixture consisted of concrete and fine sand in a ratio of 1: 7 by volume. Fine sand has been replaced by 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 and 5 parts of dairy waste, respectively. All the mixing used 350 ml of water. A concrete cube specimen was 10 x 10 x 10 cm in dimension. The moisture content, water absorption, and density were investigated at 28 days. The compression strength was studied at 7, 14, 21 and 28 days. The results showed that the compressive strength and density reduces with increasing cow feces. The moisture content and absorption of the sample tend to increase. The interlocking bricks with size 22.5 x 11.5 x 6 cm were chosen from the concrete mix proportion as fine sand to cow feces waste equals 1: 6.5 : 0.5 The moisture content, water absorption and density of interlocking bricks were also investigated within 28 days. The interlocking brick is in accordance with TCPS 602, and can be used as building materials.

Mechanical Properties of 3D Printed Parts with Thermal Annealing

2023-03-27T09:51:46+07:00

This research aims to study the mechanical properties of the Fused Deposition Modeling (FDM) 3D printing by thermal annealing method, and to provide a recommendation for the selection of suitable industrial 3D printing thermal conditions by the multi-level factorial experiments. In this research, the parameters in the study were annealing temperature, annealing hold time, and type of heating. The annealing temperature was set in the range of 60 to 70 °C, the annealing hold time was 30 to 50 minutes, and the type of heating was during annealing and post annealing. In this investigation, polylactic acid was used to print the specimens with the FDM 3D printer with a heat annealing machine. As for the results, the tensile strength was measured with a universal testing machine using Minitab software for statistical analysis and processing. From the experiments, it was found that the most suitable 3D printing thermal conditions were the annealing temperature of 60°C, the annealing hold time of 30 minutes, and during annealing. The ultimate tensile strength was 52.41 MPa.

Abandoned Mine Reclamation and Principal Considerations on Utilization

2022-11-19T09:11:34+07:00

The utilization has been presented for the seven abandoned mines as the successful projects. The development and maintenance expenditure have been used for the safety mine place throughout the time by the business owners. The projects are the Salina turda amusement park, Wieliczka underground church, the glow radioactive scuba diving, the underground mine ATV riding resort, the dirt racetracks, the Eden project and the intercontinental Shanghai wonderland hotel. The article objective is to provide the guidance of a business development for the abandoned mine location in the future. A subsequent section has established the guidelines for the utilization from abandoned mine which related with the geological information, the constraints of mine design and mine environment conditions. The seventeen principles are the types of mines, a mine owner, the present actual conditions, a route access, a location, a description of mapping surface-underground area, a geological deformation, the geotechnical risks with abandoned mining, a support of the expanded area, the water flow direction and the seasonal flooding area, a wind map, a sewage map, an interactive underground water map, the vibration level, the noise level and the biodiversity. The final section is the analytical guidelines of the domestic abandoned mines utilization. It is hoped that to future this principles can be better developed and it will be a suitable guidelines for the local abandoned mines.