IPTEK The Journal of Engineering
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Rice Identification Using Convolutional Neural Network with YOLOv7 algorithm and VGG16
Full text linkRice is the most widely consumed food worldwide. The many types of rice cause various difficulties in the process of classifying rice varieties. The process of manually classifying rice varieties that rely on human power has drawbacks including the subjectivity of assessment between observers, limited physical capabilities, and longer observation times. In this research a rice variety classification system has been developed using the Convolutional Neural Network with the YOLOv7 and VGG16 algorithms. The rice varieties classified are basmati, IR64, and rojolele varieties. The model with the YOLOv7 algorithm is trained for object segmentation of rice grains and is used to create rice grain image datasets. The model with the VGG16 algorithm was trained by transfer learning and used for classifying rice grain varieties. The model with a learning rate hyperparameter of 0,000061, the ReLU activation function, the number of neurons 256 in the second classification layer, with the fine-tuning training method, has the best performance with an accuracy value of 100%. The best VGG16 model weight is used in application implementation. Identification of the type of rice with the application can be done on the image of a batch of homogeneous and heterogeneous rice grains with various arrangements
OBSAFER: Hydrogen Power Plant from Soybean Straw and Tofu Liquid Waste in Kediri District
Full text linkIndustrial developments result in higher consumption of electrical energy with considerable emissions. Efforts to develop alternative energy are carried out to overcome climate change. Hydrogen, as a clean energy, can be produced from biomass, such as soybean straw waste. The OBSAFER innovation was created to optimize the use of soybean straw and tofu liquid waste in electrical power. The process began with soybean straw waste pre-treated with NaOH and entered into a bioreactor for a dark fermentation process with Clostridium butyricum to produce hydrogen, methane, and carbon dioxide. Then, the gas is separated by a CH4 filter and a CO2 filter, so the main product is hydrogen. The OBSAFER technology can produce 821,751 kWh/year from 21.6 tons of soybean straw waste and Clostridium butyricum from tofu liquid waste
Technical Study of Ship Plate Firing Process Time with Variation of Deformation Values
Full text linkIn the process of shipbuilding production and repair, deformation is sometimes encountered due to several factors, starting from load pressure, pulling, lifting, and welding processes. A fairing process is carried out to overcome the plate deformation, in which the plate is heated and cooled simultaneously. The method used in this research is direct time measurement during the fairing process on test plate specimens with variations in the depth of deformation curvature. The data obtained, processed, and analyzed to obtain an estimate of the fairing processing time the longer the fairing process takes, following the equation Y = 41.285X + 530.94, where X is the deformation angle, and Y is the estimation fairing processing time area per half square meter
Shallot Price Forecasting in Three Locations in Indonesia Using Generalized Space-Time Autoregressive Model
Full text linkShallots are one of the commodities that have an important role for the economy in Indonesia. Many shallot farmers, especially in production center areas, depend for their economy on shallot farming. The price of shallots in Indonesia during 2010-2022 fluctuated quite a bit. This is because the demand for shallots tends to increase over time, while shallot production is seasonal, and the distribution is uneven. The fluctuation of shallot prices and the huge costs of shallot farming result in risk and uncertainty for farmers. The forecasting method used is Generalized Space-Time Autoregressive (GSTAR). The results of the best model for predicting shallot prices in three locations in Indonesia, namely Cirebon, Tegal, and Madiun based on RMSE values, namely the GSTAR (31)-I(1) model use inverse distance normalization weights. Forecasting results for the highest shallot prices in Cirebon, Tegal and Madiun occur in the first week of August 2022. Meanwhile the lowest shallot prices in Cirebon and Madiun occur in the fifth week of August 2022, however the lowest shallot prices in Tegal occur in the fourth week of August 2022. Shallot price movement patterns in Cirebon, Tegal, and Madiun for the next 14 periods will continue to fluctuate but tends to show a downward trend. This was caused by several regions entering the harvest season, resulting in a spike in yields at the same time. As a result, the yield of shallots in the three locations was abundant and caused the price of shallots to decrease.
Stress-Strain Behavior of Confined Class C Fly Ash-Based Geopolymer Concrete
Full text linkFly ash-based geopolymer cement has recently attracted attention due to its application potential, as well as being an alternative binder with low emissions compared to conventional portland cement in concrete production. Studies intended on the mechanical properties and behaviors of structural elements produced from class C fly ash-based geopolymer concrete are important to improve the implementation. This study aimed to determine the effect of confinement on the behavior of class C fly ash-based geopolymer concrete and portland cement-based concrete. 6 specimens were made with class C fly ash-based geopolymer concrete tested under axial loading. Then, 6 specimens were made with ordinary portland cement-based concrete for comparison. The variable considered in this study is the pitch of confinement. The effect of the pitch of confinement on the enhancement strength and stress-strain of class C fly ash-based geopolymer concrete was obtained. The analytical model proposed by Richard et al. was selected to evaluate the ultimate compressive strength and ultimate compressive strain of confined geopolymer concrete in this study. The results showed that confinement reinforcement improved the strength and ductility of class C fly ash-based geopolymer concrete
Early Age Strength of Development Ultra High-Performance Concrete Using Class-F Fly Ash and Local Materials for Repair
Full text linkUltra High-Performance Concrete (UHPC) is an innovative material for such repairs because of its superior mechanical properties, strength, crack resistance, and durability. However, its high production cost, primarily due to using materials like silica fume and cement, is a significant drawback. This study explores the feasibility of incorporating fly ash and local materials into UHPCs to reduce costs while maintaining or improving their performance. As a supplementary cementitious material, fly ash enhances the compressive strength and workability of UHPC. The addition of limestone further supports early-age strength and workability. By evaluating the mechanical properties and workability of modified UHPCs, this research demonstrates the economic viability and environmental benefits of structural repairs. The results indicate that this modification can effectively enhance the early-age strength of UHPC, making it suitable for use as a repair material. The evaluation of the mechanical properties and workability of the modified UHPC suggests that these alternative materials can maintain or even improve the performance of UHPC. Thus, this approach offers a more economically viable and environmentally friendly solution for structural repairs
Characterization of Hydroxyapatite From Kupang Shells and Its Synthesis with Polycaprolactone for 3D Printing Filament
Full text linkThe number of deaths or fatalities due to accidents in Indonesia is increasing. In addition, traffic accidents can cause serious injuries such as damage to the skull. The bone implantation technique currently used is an autograft, but this technique has some limitations. This limitation of autograft can be overwhelmed with synthetic bone implants, one of which uses a mixture of Polycaprolactone (PCL) and Hydroxyapatite (HAp). A combination of HAp and PCL is recommended because the two materials complement each other's weaknesses and can increase elasticity and quality to produce suitable filaments for 3D printing processes. This study used hydroxyapatite from Kupang Shells by calcination and precipitation methods. Then do the test XRF, XRD, FTIR, and SEM to determine the quality. The results showed that HAp synthesized from Kupang Shells had potential characteristics as bone implants. Next, two methods were used to mix PCL with HAp as a 3D printing filament for bone implants: the dry and wet methods. After that, it is analyzed with SEM and Mechanical Strength. The results of the SEM test of HAp particles in the wet method have more even distribution and a smoother surface than in the dry method. The impact is visible on the filament's mechanical test, which shows better results in the wet method
Carbon Dioxide (CO2) Absorption Process Using Sodium Hydroxide (NaOH)
Full text linkAn absorption process can be carried out to reduce carbon dioxide gas emissions in the surrounding environment. Absorption is a contact process between a mixture of gas and liquid that aims to remove one of the gas components by dissolving it in a suitable liquid. In this study, the CO2 absorption process was carried out to determine the effect of CO2 flow rate on the amount of CO2 absorbed with NaOH absorbent. The results showed that the correlation between CO2 flow rate and absorption factor was inverse because an increase in CO2 flow rate caused the contact between CO2 gas and NaOH to decrease. As a result, the absorption factor decreased because the ratio of CO2 was greater than the absorbent. While the relationship between L/V and the absorption factor is directly proportional if the flow rate of the liquid increases, the retained liquid tends to saturate and can accelerate the diffusion of CO2 in the water, so the absorption factor also increases. In addition, after the absorption of CO2 gas, sodium carbonate is produced, which is the result of the reaction of CO2 with NaOH
Carment: Magnesium Cement From Glass Waste As A Solution To The Cement Industry's Carbon Emission Problems
Full text linkIn dealing with carbon emissions generated from the cement industry in general, the author has the idea to use Carment. Carment is a concept of carbon absorbing cement based on magnesium silicate which is derived from silica and is able to reduce carbon emissions from the manufacturing process compared to the manufacture of cement in general. There are several solutions that have existed in overcoming the problem of carbon emissions from the cement industry, such as the Waste Heat Recovery Power Generator (WHRPG), reducing the clinker ratio through blended cement products, and using alternative fuels to replace coal. However, its existence is still quite expensive and has not been able to overcome the problem of carbon emissions resulting from the cement industry. Carment is an innovation in the industrial sector where Carment as a magnesium cement from glass waste can solve the problem of carbon emissions from the calcination process. The availability of glass waste, which has a high availability, contains more than 70% silica and is inexpensive, increases the potential to produce magnesium cement from glass waste in Indonesia
Designing a Supply Chain Visibility Information System for the Manufacturing Industry
Full text linkThis paper evaluates the design and success of an Information System developed in a just-in-time UK manufacturer to combat the lack of visibility and financial impact caused by supply chain disruptions related to extreme weather and traffic events. An information system design is first presented through the use of leading academic models, with a subsequent evaluation of perceived success via 4 employee interviews within the UK manufacturer. The DeLone and McLean model Multi-Perspective Evaluation model is then used to present the interviewees responses. This paper finds the newly introduced IS to be a partial success in meeting project objectives via the reduction of incident response time by 30 minutes per incident, and the centralization of key data points. This paper contributes to literature through the provision of framework and learnings for other organizations to build and act upon, in the aims of reducing their own supply chain disruption due to extreme weather and traffic events