IPTEK The Journal of Engineering
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Evaluating the Internet of Things Platform for CO2 Monitoring in Sugar Refineries
Full text linkThe sugar cane industry in Indonesia makes a substantial contribution to CO2 emissions, which have a negative impact on the environment and society. This study attempts to incorporate the Internet of Things (IoT) as a reliable indicator of air quality in the sugar cane industry, specifically focusing on the CO2 metric. The research aims to monitor the air quality and provide air quality information. This aligns with the eleventh Sustainable Development Goal, which emphasizes the importance of Sustainable Cities and Communities. The implementation of a smart factory concept utilizes IoT technology to actively monitor and analyze gas emissions in real-time monitoring and assessment of the air quality so that when the CO2 level exceeds the safe limit, it can provide a warning and appropriate action can be taken immediately. The system comprises a PIC microcontroller, an ESP-8266 (wi-fi) module, and a gas analyzer. These components work together to identify and alert users when gas emissions exceed pre-established thresholds. Furthermore, the system provides consumers with regular data and notifications, thereby enhancing environmental management and monitoring. The evaluation of IoT-based CO2 monitoring can raise public awareness and air quality information. Aligning with the United Nations' Sustainable Development Goals, implementing IoT technology in the sugar industry offers a practical approach to reducing emissions and promoting sustainability
Hydrodynamic Force Comparison on Multi-Hull, Monohull and Single-to-Twin After Ship Hull (STASH) Based on Seakeeping Criteria
Full text linkAn investigation into the hydrodynamic force and seakeeping of single-to-twin after ship hull (STASH) and multi-hull geometry was done successfully. STASH is characterized by its monohull-shaped design in the fore part and twin hull in the rear part creating unique performance, especially seakeeping which being the focus study to provide seaworthiness. The method of accomplishing this study was through computer simulation using Maxsurf: Motion for seakeeping and hydrodynamic force analysis. The overall results were compared with published data and mathematical models for validation purposes. The results are believed to be useful for the development of the ship design and performance
Role of Limestone Addition in Improving the Initial Compressive Strength of Geopolymer Concrete for Corrosive Environment Repair
Full text linkGeopolymer Concrete (GC) is highly durable in corrosive environments, making it a viable material for repair. However, its initial compressive strength was below the 7 MPa required at 1-day age. Adding fine limestone (45 μm) can improve GC's density and early strength. This study explores the effects of adding 0, 3, 5, and 7% limestone and 1% sucrose superplasticizer to GC 16M. The compressive strength was tested at 1, 3, 7, and 28 days, along with slump, permeability, and resistivity tests to assess the durability. The results show that adding 5% limestone yields the optimal GC performance for repairing corrosive environments. The compressive strengths were 15.96, 28, 43, and 67.14 MPa at 3 days, 43 MPa at 7 days, and 67.14 MPa at 28 days, with a slump of 120 mm. The permeability and resistivity results were 0.128 E-16 m² and 57.87 kΩ-cm, indicating normal corrosion levels. These findings confirm that GC with 5% limestone meets the durability and strength requirements of repair materials in corrosive environments
The Effect of Cabbage Waste Pretreatment on Lignocellulose Content for Bioethanol Production
Full text linkCabbage waste represents a resource rich in lignocellulose, offering substantial potential as a raw material for bioethanol production. However, the nature of lignocellulosic complexes necessitates effective pretreatment strategies to enhance cellulose accessibility. This study aims to determine the effect of pretreatment on cabbage waste on changes in lignocellulosic content before and after pre-treatment to determine the influence of solution concentration and pretreatment duration of cabbage waste on the level of reducing sugars, which will subsequently affect bioethanol fermentation. In this research, cabbage waste was pretreated using H2SO4 1 M and alkaline NaOH 1 M for 1 hour to determine the pretreatment agent that produced the highest cellulose content. Furthermore, the concentration (1 M; 1.5 M; 2 M) and the pretreatment time (1 hour; 1.5 hours; 2 hours) will be varied to produce the highest reducing sugar content, which will be continued to the Simultaneous Saccharification and Fermentation (SSF). The results showed that pretreatment using H2SO4 produced the highest change in cellulose content. Pre-treatment using H2SO4 at a concentration of 1.5 M for 1.5 hours produced the highest reducing sugar concentration of 0.32 g/L. The highest bioethanol content was obtained during fermentation for 72 hours at 22.25%
Analyzing the Performance of Reverse Osmosis Membranes After the Cleaning Process: Case study Performed at PT. XYZ.
Full text linkPT. XYZ uses a reverse osmosis (RO) system in demin water treatment. One of the weaknesses of the RO system is the formation of fouling on the membrane, which can reduce the performance of the membrane, so it is necessary to carry out an appropriate cleaning process to remove deposits on the surface of the membrane, restore the separation characteristics, and restore the normal capacity of the system. This research aims to examine the effect of cleaning on the performance of reverse osmosis membranes in the PT. XYZ with requirements for reverse osmosis membrane type FILMTEC BW30–400 IG. The research was conducted for 8 weeks by collecting data on the reverse osmosis control box and control room in the form of product flow rate, feed conductivity, and product conductivity. Based on the results of the study, it can be concluded that the effect of cleaning on membrane performance can only extend the life of the membrane and cannot meet the specifications for the working parameters of the reverse osmosis membrane, which can be seen in the salt rejection, salt passage, and flux values obtained in this study
Design of IoT-Based One Axis Passive Solar Tracker
Full text linkPhotovoltaic (PV) is a device that has the ability to convert solar energy into electrical energy. The most popular way to improve performance in PV is to add solar tracker technology. There are 2 solar tracker methods, namely passive and active, in this study focuses on the passive method where the slope angle of the PV is calculated using astronomical calculations. The difference in previous research is that the PV tilt angle can be adjusted via cellphone, it has a function if the Tracker system is damaged it can be replaced first using this system. In this study, the INA219 sensor is used to measure the current, voltage, and power at the PV output, and the GY52MPU 6050 sensor is used to measure the PV slope. The results obtained from this study are the accuracy value of the INA219 sensor is 98.67% for power and 97.67% for current and there is an error of 1.33% for power and an error of 2.33% for current values. There is also an accuracy value of the GY52MPU6050 sensor which is 99.6% and an error of 0.4%. IoT is also carried out where if the current value is greater, the delay that occurs is also higher. There is also an increase in performance between fixed-based and tracker by 21% in sunny conditions, and 15% in cloudy conditions
Cultivation of Low-Potassium Paddy Straw Mushrooms (Volvariella volvacea) on Proline-Based Osmolyte Growing Medium to Enhance Nutritional Variety for Hyperkalemia Patients
Full text linkThe increasing variety of food choices has led to a rise in diet-related diseases, as people often prioritize taste over nutritional content. The high consumption of sodium and potassium-rich foods has contributed to a growing number of kidney disease cases. While many studies have focused on producing low-potassium foods, these often result in suboptimal growth. Mushrooms are a nutrient-rich food source, but their high potassium content makes them unsuitable for kidney disease patients. This study aims to determine the effects of different growing media compositions and osmolyte supplementation on potassium content, yield, and mycelium growth duration in low-potassium mushrooms. The cultivation was conducted using the baglog method, starting with the preparation of a growth medium composed of a combination of sengon wood sawdust, rice bran, and dried kepok banana leaves, which were sterilized before inoculating mushroom spawn and incubated in a kumbung for 35 days. Mycelium length was observed during growth, and potassium content was tested post-harvest. The results showed that proline supplementation had an effectiveness threshold, with 3% proline in composition B yielding the best hyphae development and the highest yield of 296.67 grams with the lowest potassium content. For glycerol treatment, 5% glycerol in composition A produced the highest yield and lowest potassium content, while 1% glycerol in composition B resulted in the longest hyphae growth
Performance Changes in Mass and Compressive Strength of High-Calcium Fly Ash Based Geopolymer Concrete Due to Sodium Sulphate Exposure
Full text linkThe sulfate environment is one of the conditions that significantly affect the durability of concrete. Sulfate attack causes cracks and affects the quality of the concrete. Therefore, it is necessary to innovate concrete that can withstand the aggression of this sulfate attack. Geopolymer concrete is a breakthrough that can be developed as an alternative material without using Portland cement as the ingredients, yet by using class F fly ash as the primary source material. On the other hand, the availability of class C fly ash with high CaO content is highly abundant in Indonesia. The high calcium content in this fly ash will cause the fresh geopolymer concrete to harden rapidly. Previous studies used sucrose as an additive to overcome this rapid hardening problem. However, its effect on the geopolymer concrete exposed to sulfate ingression requires further investigation. In this study, the geopolymer concrete was produced by using class C fly ash and sucrose. The sulfate ingression was simulated by immersing the concrete specimen in the sodium sulfate solution while the mass changes and compressive strength were examined. pH measurement of the sodium sulfate solution was also carried out to provide a different perspective on the data analysis. Cylindrical specimens, measuring 10 cm x 20 cm, were produced using the dry-mixing method and the characteristic strength of 28 MPa according to SNI 2847–2019. From the results, geopolymer concrete with sucrose showed a high workability performance through the high slump value obtained. Nevertheless, the experimental results also indicated the declining strength of geopolymer concrete after the sulfate exposure. However, only a slight reduction was observed. The strength residue still satisfies the minimum requirement of SNI 2847-2019. It shows the potential of geopolymer concrete to be used as a construction material in a harsh environment with high sulfate content
Physicochemical Properties of Crude and Purified of Glucomannan Flours
Full text linkKonjac glucomannan (KGM) is a versatile polysaccharide extracted from Amorphophallus species tubers. Commonly, extracted crude porang flour still has some impurities which limits the application of utilizing the material. High purity of processed glucomannan flour could satisfy the demand of growing awareness of healthy diet and industrial scale production. In this study, the physicochemical properties of purified glucomannan flour compared with crude porang flour were investigated. Thermal stability of the purified flour was increased indicated by higher degradation temperature, which was revealed by Thermogravimetric Analysis (TGA). The structural characteristics were investigated by FTIR and X-ray Diffraction (XRD) analysis. In addition, Scanning Electron Microscopy (SEM) was conducted to study the morphology and grain size of crude and purified flours. The results revealed that purified glucomannan flour has better thermal stability, higher crystallinity, smaller granule size and significantly higher viscosity compared to crude flour
Positioning Control of Satellite Antenna for High Speed Response Performance
Full text linkDish antennas are essential elements in establishing communication between satellite and earth station. The response speed of the position control process of a dish antenna mounted on a moving vehicle that communicates via NigComSat-1R with a central control office is affected by round trip or time delay. Therefore, there is need to design a control system that will address this problem in order to achieve high speed positioning response. The mathematical models representing the dynamics of the antenna positioning system were obtained. A back propagation neural network (BPNN) based proportional integral and derivative (PID) controller was designed and added to the antenna position control loop. The resulting system was modelled in MATLAB. Simulation results indicated that it provided a rise time of 0.027 s, settling time of 1.06 s and overshoot of 0% at peak time of 0.06 s. This shows that the response speed of the control process using the designed BPNN-PID is 37 degree per second. Comparison with previous controllers applied to the same system indicated that BPNN-PID controller outperformed all of them. Generally, the BPNN-PID controller is suitable for high speed position control of the antenna and improves overall performance