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Contact Name
M. Yusuf
Contact Email
yusuf@pnb.ac.id
Phone
+62361-701981
Journal Mail Official
logic@pnb.ac.id
Editorial Address
Unit Publikasi Ilmiah, P3M, Politeknik Negeri Bali, Jl Kampus Bukit Jimbaran, Badung, Bali, Indonesia
Location
Kab. badung,
Bali
INDONESIA
Logic : Jurnal Rancang Bangun Dan Teknologi
Published by Politeknik Negeri Bali
ISSN : 1412114X     EISSN : 25805649     DOI : https://doi.org/10.31940/logic.v21i3
Core Subject : Engineering,
Logic : Jurnal Rancang Bangun dan Teknologi is a peer-reviewed research journal published by Unit Publikasi Ilmiah, Pusat Penelitian dan Pengabdian Masyarakat, Politeknik Negeri Bali, aiming at promoting and publishing original high quality research in all disciplines of engineering and applied technology. All research articles submitted to Logic should be original in nature, never previously published in any journal or presented in a conference or undergoing such process across the world. All the submissions will be peer-reviewed by the panel of experts associated with particular field. Submitted papers should meet the internationally accepted criteria and manuscripts should follow the style of the journal for the purpose of both reviewing and editing.
Articles 171 Documents
The Effect of Composition and Type of Metal Filler on Heat Resistance of Silica Rubber Matric Composites R.N. Akhsanu Takwim; Anggit Murdani; Purwoko; Bayu Pranoto; Naufal Reza Putra
Logic : Jurnal Rancang Bangun dan Teknologi Vol. 23 No. 3 (2023): November
Publisher : Unit Publikasi Ilmiah, P3M, Politeknik Negeri Bali

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31940/logic.v23i3.169-174

Abstract

Thermal Tensioning is one of the methods use to minimise the occurrence of residual stress and unwanted distorsion during welding. One of the thermal tensioning methods is Static Thermal Tensioning (STT), which involves countering thermal stress during welding. The STT method requires an active cooling behind the welding line. Several properties are required for the coolant material, such as thermal conductivity, heat resistance, and good flexibility. To achieve the desired properties, a mixture of different materials was used, commonly called a composite. The purpose of this study is to know the effect of filler metal composition and type on the heat resistance of silica rubber matric composites. This study used 2 independent variables: the filler composition in composites with variations of K1 (60%) and K2 (70%), and the type of filler metal, aluminium and copper powder with variation J1 (100%-0%), J2 (75%-25%), J3 (50%-50%), J4 (25%-75%), and J5 (0-100%). The testing process used Thermogravimetry Analysis (TGA) method with replication 2 times. The results of this study showed the specimens with K1;J1 composition,containing 60% pure aluminium filler metal, showed the best heat resistance with a final weight of 88,25%. While specimens with K2;J5 composition, containing 70% pure copper filler metal, showed the worst heat resistance with a final weight of 74,25%.
KINETICS OF BIODEGRADATION OF CASSAVA STARCH - COFFEE GROUNDS BIOPLASTICS IN SOIL AND AQUEOUS MEDIA Komang Widhi Widantha; Risa Nurin Baiti; I Wayan Padma Yogi Asana; Ni Luh Wisma Eka Yanti; Anisa Fitri
Logic : Jurnal Rancang Bangun dan Teknologi Vol. 26 No. 1 (2026): March
Publisher : Unit Publikasi Ilmiah, P3M, Politeknik Negeri Bali

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31940/logic.v26i1.79-85

Abstract

The environmental concerns associated with petroleum-based plastics have driven the development of biodegradable alternatives. This study investigates the biodegradation kinetics of cassava starch–coffee grounds bioplastics under soil and aqueous conditions. Bioplastic films were prepared using the solution casting method with 10% (w/w) spent coffee grounds and glycerol as a plasticizer. Biodegradation tests were conducted over 14 days, measuring weight loss at predetermined intervals. The results showed that the bioplastics degraded significantly faster in soil, with 61.3% weight loss within seven days, compared to 34.2% in aqueous media. The degradation trends followed first-order kinetics, indicating that the rate of biodegradation depended on the remaining bioplastic mass. The addition of coffee grounds enhanced biodegradability by promoting microbial colonization and water absorption, while soil conditions accelerated enzymatic breakdown. This study demonstrates that cassava starch–coffee grounds bioplastics are promising sustainable materials, offering a pathway for organic waste valorization and supporting circular economy principles.
AUTOMATIC POLYALUMINIUM CHLORIDE (PAC) DOSING CONTROL SYSTEM FOR WATER PURIFICATION USING NODEMCU-ESP32 Fauzan Amri; Bagus Dharmawan Hadi; Tri Haryanti; Revan Lutfiar Rizky; Sri Rahayu; Aulia Wanda Alifah
Logic : Jurnal Rancang Bangun dan Teknologi Vol. 26 No. 1 (2026): March
Publisher : Unit Publikasi Ilmiah, P3M, Politeknik Negeri Bali

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31940/logic.v26i1.10-16

Abstract

This study discusses the design and implementation of a control system for a water pump used to inject PAC solution into raw water, thereby producing treated water that meets quality standards. The pump’s operating duration is adaptively controlled based on the turbidity level of the water to be clarified. The system employs a turbidity sensor as the input signal, which generates data to be processed by a NodeMCU-ESP32 device serving as the central controller. Subsequently, the controller issues commands to the water pump, functioning as the actuator, to perform the PAC injection process. Experiments were conducted on three types of water sources, namely river water, paddy field water, and groundwater, with initial turbidity levels of 29, 35, and 64 NTU, respectively. The results showed that all water samples were successfully clarified to a turbidity value of 0 NTU within 47, 120, and 137 minutes, respectively. At the beginning of the treatment process, turbidity value readings exhibited fluctuations due to the initial mixing of PAC solution with raw water. However, the turbidity values steadily decreased once the PAC and suspended particles were fully settled. To facilitate monitoring, the system is equipped with an IoT feature via the Firebase platform, which displays numerical indicators including water volume, turbidity level, pump speed, pump operating duration, and water status classified according to clarity. This innovation is expected to contribute as an effective water purification automation technology, expecially for small- and medium-scale industries.
PROTOTYPE DESIGN OF BATTERY CHARGING SYSTEM WITH THE USE OF REPEATED WATER CYCLE AT PICOHIDRO POWER PLANT MARIANUS CHRISTOSANTO NOFU; Frans Likadja; Almido Ginting
Logic : Jurnal Rancang Bangun dan Teknologi Vol. 26 No. 1 (2026): March
Publisher : Unit Publikasi Ilmiah, P3M, Politeknik Negeri Bali

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31940/logic.v26i1.48-60

Abstract

Picohydro power plant (PLTPH) is the smallest scale hydroelectric power plant with a capacity of less than 5 kW. Still like other hydropower plants, PLTPH applications are also often constrained by changes in water discharge due to the dry season. This research is here to design and test a prototype battery charging system with repeated water cycles on PLTPH consisting of several components such as water pumps, pelton turbines, DC generators, Smart Valves and relay time to control the charging system and also the battery as an energy store. The research method used is an experimental method, where the focus of the test is the output of the generator at a certain height and discharge and then compared to the discharge of water that is pumped back to be reused. As a result, the output of the generator was obtained at a height of 3.9m, namely 1.7V and 2.4A, which is low enough to be used in charging the battery, so a step up module is needed to increase the generator output voltage. Testing was also carried out to see how the Solar Panels handled the load at the beginning of the system. This system is still not efficient in charging time, but it is quite integrated both in analysis and concept so that it can be developed, of course, with more mature consideration and concepts
EFFECT OF SCREW CONVEYOR SPEED AND CUTTER DIAMETER ON THE PRODUCTION PERFORMANCE OF MEATBALL FORMING MACHINE Siti Duratun Nasiqiati Rosady; Fitrah Bisma Taimullah Al Jahfal; Ardhi Prawira Rohim; Talifatim Machfuroh; Zakiyah Amalia; Fica Aida Nadhifatul Aini
Logic : Jurnal Rancang Bangun dan Teknologi Vol. 26 No. 1 (2026): March
Publisher : Unit Publikasi Ilmiah, P3M, Politeknik Negeri Bali

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31940/logic.v26i1.17-28

Abstract

Manual meatball production in small and medium enterprises often results in inconsistent product mass and low production efficiency. This study aims to analyze the effect of screw conveyor speed and cutter diameter on the production performance of an automatic meatball forming machine. The experiment was conducted at the Mechanical Engineering Laboratory, Politeknik Negeri Malang, using the Design of Experiment (DOE) factorial method. The independent variables were screw conveyor speed (159 rpm, 186 rpm, and 236 rpm) and cutter diameter (15 mm, 20 mm, and 25 mm), while the dependent variables were the produced meatball mass and production capacity. Data were analyzed using Minitab 21 software with a Two-Way ANOVA test to evaluate the influence of the main factors and their interaction on the output. The results show that both independent variables significantly affect the meatball mass (p-value < 0.05). Higher screw conveyor speeds increased meatball mass but reduced the number of meatballs produced, while larger cutter diameters generated heavier meatballs with lower production capacity. Response optimization analysis revealed the best combination at a screw speed of 124 rpm and a cutter diameter of 30 mm, yielding a desirability value of 0.93. This configuration produced meatballs within the optimal weight range of 15–25 grams with minimal power consumption. It can be concluded that the precise adjustment of screw conveyor speed and cutter diameter significantly improves product uniformity, machine performance, and production efficiency, supporting productivity enhancement in small-scale food manufacturing industries.
EFFECT OF USING WASTE PLASTIC AS A BINDING MATERIAL ON THE PERFORMANCE OF PLASTIC WASTE-BASED PAVING BLOCKS Risman Firman; Joey Limbongan; Muhammad Ali Taufan
Logic : Jurnal Rancang Bangun dan Teknologi Vol. 26 No. 1 (2026): March
Publisher : Unit Publikasi Ilmiah, P3M, Politeknik Negeri Bali

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31940/logic.v26i1.1-9

Abstract

The increasing volume of plastic waste poses significant environmental challenges, particularly due to its slow degradation and the accumulation of non-biodegradable materials in landfills. This study explores an alternative utilization of plastic waste by transforming it into a binding material for paving blocks. A quantitative experimental approach was employed to examine how varying proportions of molten plastic and sand influence the physical and mechanical properties of paving blocks. Four mixture variations were tested 100% plastic, 75% plastic : 25% sand, 50% plastic : 50% sand, and 25% plastic : 75% sand, each molded into standard 20 × 10 × 8 cm specimens and evaluated for compressive strength, water absorption, and abrasion resistance. The results demonstrate a clear trend in which higher plastic content leads to improved mechanical performance. The 75% plastic composition exhibited the best overall results, achieving a compressive strength of 11.64 MPa, low water absorption of 1.32%, and an abrasion rate of 0.098 mm/min. The 100% plastic variation also performed well, with a compressive strength of 10.82 MPa and the lowest abrasion values ranging from 0.037 to 0.062 mm/min. In contrast, the low-plastic mixture (25%) showed a marked decline in performance, indicated by a compressive strength of 8.91 MPa, water absorption of 3.78%, and abrasion rates of 0.201–0.226 mm/min. Based on SNI 03-0691-1996, PB100 and PB75 meet Class A quality standards, PB50 is categorized as Class C, and PB25 falls into Class D. Overall, the findings confirm that plastic waste can serve as an effective binder, producing paving blocks with low porosity, high abrasion resistance, and enhanced mechanical properties. These results highlight the promising potential of plastic waste as a sustainable construction material, contributing to both waste reduction and the development of environmentally friendly building products.
MATHEMATICAL MODELING AND THERMAL ANALYSIS OF A THERMOELECTRIC COOLER BOX USING A WATER-COOLING BLOCK AND HEATSINK–FAN SYSTEM I Nyoman Agus Adi Saputra; Adi Winarta; I Wayan Sutina
Logic : Jurnal Rancang Bangun dan Teknologi Vol. 26 No. 1 (2026): March
Publisher : Unit Publikasi Ilmiah, P3M, Politeknik Negeri Bali

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31940/logic.v26i1.29-38

Abstract

This study presents a mathematical modeling and thermal performance analysis of a Thermoelectric Cooler Box (TEC) equipped with two hot-side heat rejection systems: a Water Cooling Block (WCB) and a Heatsink–Fan (HSF). Thermoelectric cooling offers an environmentally friendly alternative to vapor-compression refrigeration because it operates without refrigerants and requires only low-voltage DC power. The objective of this work is to evaluate the influence of electrical current on temperature distribution, cooling capacity (Qc), and the coefficient of performance (COP) of a TEC1-12706 module under both cooling configurations. The mathematical model is formulated based on the energy balance between the cold and hot sides, incorporating the Peltier effect, thermal conduction, and Joule heating losses. Numerical simulations were performed in Python for currents ranging from 1 to 7 A. The results show that the WCB reduces the hot-side temperature (Tₕ) by 6–8 °C compared with the HSF, indicating superior heat rejection. However, the HSF system achieves a slightly higher COP (about 5–7%) due to the lower cold-side temperature (Tc) obtained in the WCB configuration, which reduces the effective Peltier cooling term. The maximum COP for both systems occurs at 3–4 A, corresponding to a temperature difference (ΔT) of approximately 28 °C. Although the cooling capacity of the WCB is slightly lower (<10%) due to increased back-conduction, it offers better thermal stability and long-term performance consistency. Overall, the developed mathematical model accurately represents the TEC’s thermal behavior and provides a reliable foundation for optimizing water-cooled thermoelectric designs.
NUMERICAL STUDY ON THERMAL PERFORMANCE OF MINI-CHANNEL COOLING ON CYLINDRICAL LITHIUM-ION BATTERY COOLING SYSTEM Elvi Ermadani; James Julian; Bima Rakha Adhitama; Fitri Wahyuni; Riki Hendra Purba; Fathin Muhammad Mahdhudhu; Adi Winarta
Logic : Jurnal Rancang Bangun dan Teknologi Vol. 26 No. 1 (2026): March
Publisher : Unit Publikasi Ilmiah, P3M, Politeknik Negeri Bali

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31940/logic.v26i1.86-94

Abstract

This study investigates how a liquid-based cooling configuration influences the thermal behavior of a cylindrical lithium-ion (Li-ion) battery pack through numerical analysis. The work underscores the crucial role of proper thermal regulation to maintain operational safety and prolong battery lifespan in high-demand applications such as electric vehicles (EVs). Three cooling-channel diameters—4, 6, and 8 mm—were examined under a 5C discharge condition. The findings indicate that the 8 mm channel offers the most advantageous performance, delivering the lowest maximum temperature, quicker thermal stabilization, and improved temperature uniformity. Conversely, the 4 mm channel resulted in elevated peak temperatures and a temperature gradient (ΔT) of 8.3 °C, which may intensify hotspot formation and accelerate cell degradation. Overall, the results emphasize the importance of selecting an appropriate cooling-channel diameter to effectively mitigate thermal stress.
EXPERIMENTAL AND CFD ANALYSIS OF A LABORATORY-SCALE PARALLEL FLOW SHELL AND TUBE HEAT EXCHANGER Alviani Hesthi Permata Ningtyas; Siti Duratun Nasiqiati Rosady; Ilham Arifin Pahlawan; Rilo Chandra Muhamadin
Logic : Jurnal Rancang Bangun dan Teknologi Vol. 26 No. 1 (2026): March
Publisher : Unit Publikasi Ilmiah, P3M, Politeknik Negeri Bali

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31940/logic.v26i1.39-47

Abstract

A heat exchanger is a device that functions to change the temperature of a fluid by utilizing the heat transfer mechanism from a high-temperature fluid to a lower-temperature fluid. This study was conducted to design and analyze the performance of a shell and tube heat exchanger with a parallel flow configuration on a laboratory scale. The design process focused on determining the main dimensions and components, such as tube length and the ratio between shell and tube diameters, to ensure optimal operation for laboratory experiments. After the device was successfully fabricated, experiments were carried out to obtain temperature data of the hot and cold fluids at both the inlet and outlet. These experimental data were then compared with the results of numerical simulations using ANSYS Fluent software based on the Computational Fluid Dynamics (CFD) method. The simulation was used to visualize the flow pattern and temperature distribution within the heat exchanger, as well as to calculate heat transfer efficiency. The results showed good agreement between the simulation and experimental data, with only a 1% deviation, where the inlet temperature of the hot fluid was 65°C and the outlet temperature was 38°C, indicating the validity of the numerical model used. From this study, it can be concluded that the combination of experimental design and CFD simulation analysis provides a more comprehensive understanding of the temperature distribution and efficiency of a shell and tube heat exchanger with a parallel flow configuration.
A NUMERICAL STUDY OF CORRUGATED SIERPINSKI CARPET ON SOLAR DRYER Lohdy Diana Diana; Arrad Ghani Safitra; Eli Novita Sari; Firman Yunan Saputra; Muhammad Yusuf Febrian Putra; Mutia Ayu Agustina; Ar Rayyan Ikhsan Syahputra
Logic : Jurnal Rancang Bangun dan Teknologi Vol. 26 No. 1 (2026): March
Publisher : Unit Publikasi Ilmiah, P3M, Politeknik Negeri Bali

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31940/logic.v26i1.71-78

Abstract

Solar dryers have problems with low heat transfer performance and uneven temperature distribution, resulting in low efficiency. The efficiency of solar dryers depends on the design of the absorber plate, namely how much it can absorb solar heat. This study applies a Siepinski carpet with a complex structure and large dimensions, resulting in iterations called fractals. This study aims to improve the efficiency of solar dryers as an alternative to the negative impact of falling tomato prices, to determine the effect of the Siepinski Carpet Corrugated fractal distance on the performance of solar dryers in terms of heat transfer, to compare corrugated absorber plates with 3 siepinski carpet corrugated based on variations in the fractal ratio (RF), namely the ratio of the fractal center distance to the fractal length RF = 1, RF = 0.75, and RF = 0.6, on the performance of solar dryers, as well as to determine the distribution of temperature, pressure, and air flow velocity in the collector using the Computational Fluid Dynamics (CFD) simulation method. This study used simulation methods that was conducted in a laboratory. In conclusion, the fractal ratio strongly influences airflow behavior and temperature distribution, where overly dense or overly open configurations enhance heat transfer, while intermediate obstruction can reduce thermal performance. Among the cases studied, RF = 1 and RF = 0.6 provide more effective and consistent heat transfer compared to RF = 0.75.