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separating and shredding organic and inorganic waste. This study aims to analyze the process of shredding household waste using the Computational Fluid Dynamics–Discrete Element Method (CFD-DEM) and determine the optimal operational parameters based on variations in rotor speed. The research method uses numerical simulation with SolidWorks 2024 software for geometric modeling and Ansys Rocky 2023 R1 for CFD-DEM simulation. The rotor speed variations used are 1000 RPM, 2500 RPM, and 4000 RPM with a mass flow rate of 4 tons/hour and a simulation duration of 2 seconds. The parameters analyzed included particle mass flow rate, shredding characteristics, and power consumption. The simulation results showed that a speed of 1000 RPM produced the most optimal performance with a maximum capacity of ±4 tons/hour and a stable shredding response compared to other variations. At 2500 RPM, there were high fluctuations with low capacity (±0.6 tons/hour), while at 4000 RPM, the capacity was moderate (±1.1 tons/hour) but still did not exceed the performance of 1000 RPM. Based on these results, it can be concluded that a rotor speed parameter of 1000 RPM is the most effective condition for improving the grinding efficiency and production capacity of a hammer mill-type Depackaging machine based on CFD-DEM simulation.

The increasing integration of internet technology in educational institutions requires structured network governance to ensure that digital resources support academic activities effectively. Unrestricted access to online platforms often leads to non-academic usage such as online gaming and social media engagement during instructional hours, which may reduce learning concentration and degrade network performance. This research develops and evaluates a network access control simulation using a MikroTik RouterBoard RB951Ui-2HnD device. The system applies firewall filtering mechanisms, hotspot-based authentication, and bandwidth allocation strategies through Simple Queue configuration. Network segmentation is implemented to differentiate teacher and student access privileges. The study adopts a Research and Development (R&D) approach to design, configure, test, and evaluate the proposed system. Testing results indicate that the firewall configuration successfully restricts access to selected online games (Mobile Legends, Clash of Clans, Roblox) and social media platforms (YouTube, TikTok, Shopee, Instagram, Telegram). Furthermore, bandwidth management demonstrates effective traffic prioritization, ensuring more stable allocation for teacher accounts in accordance with configured maximum limits. The findings confirm that structured firewall and bandwidth policies can improve network discipline, enhance performance stability, and support a controlled digital learning environment in schools.

This community service activity aims to improve the First Aid Awareness of students at SMAN 5 Tegal through health education and first aid simulation for accident management. The background of this program is based on the high potential for mild to moderate emergency incidents in the school environment, such as fainting, open wounds, nosebleeds, choking, and seizures, as well as the limited knowledge and practical skills of students in providing appropriate initial assistance. The implementation method consisted of three stages: preparation, delivery of health education using presentations and demonstrations, and hands-on simulation, followed by evaluation through knowledge assessment and skills observation. The participants were 54 students representing three grade levels. The expected outcomes of this activity include an improvement in students’ conceptual understanding and practical ability to perform first aid quickly, correctly, and safely before professional medical help arrives. In addition, this program is expected to foster emergency responsiveness, increase students’ confidence in handling accident situations at school, and contribute to the development of a safer and more prepared school environment. The outputs of this activity include increased knowledge and skill scores, documented implementation, and publication of a community service article in a SINTA-indexed journal.

Plastic waste has become one of the main environmental problems due to its nature, which is difficult to decompose naturally and can cause environmental pollution. One alternative waste treatment method that can be applied is to use a plastic melter to melt and recycle plastic waste into useful products. However, the design of plastic melters often lacks consideration of structural strength and safety aspects during the operation process. This study aims to design and engineer a plastic melter using the Finite Element Analysis (FEA) simulation approach to analyze structural resistance to thermal and mechanical loads that occur during the operation process. The research method was carried out through 3D design modeling of plastic melter components using Solidworks software, followed by analysis with FEA simulation on the main component, namely the melting tube. The parameters analyzed include the distribution of von Mises stress, the amount of displacement, and the safety factor. The analysis results show that the analyzed components experience von Mises stress distribution and displacement that are still below the material tolerance limits, with safety factor values above the recommended safety limits. Thus, the resulting plastic melter design is declared safe and can proceed to the manufacturing process. Therefore, the plastic melter design is safe, strong, and feasible to be realized as an effective and sustainable plastic waste processing technology solution.

Coffee husk is an agro-industrial waste with significant potential to be utilized as a renewable energy source through the fast pyrolysis process. This study aims to analyze and optimize gas production from the fast pyrolysis of coffee husk biomass using a screw reactor through single-particle-based Computational Fluid Dynamics (CFD) simulations. The simulations were conducted by varying the operating temperature at 500°C, 600°C, and 700°C to examine pressure distribution, heat transfer, particle temperature, and the formation of pyrolysis products, namely bio-oil, biogas, and biochar. The modeling was performed using COMSOL Multiphysics 6.2 with a numerical approach to represent thermal phenomena and biomass decomposition reactions during the pyrolysis process. The simulation results indicate that increasing temperature significantly affects the rate of heat transfer and the temperature distribution of coffee husk particles. At 600°C, heat transfer and temperature distribution are more uniform compared to 500°C, although heating at the particle core is not yet fully optimal. The pressure distribution shows a stable flow of pyrolysis gas from the bottom to the top of the reactor. In terms of products, increasing temperature leads to a reduction in biochar and bio-oil formation due to the occurrence of secondary reactions, while biogas production increases. The highest gas production is achieved at 700°C, indicating the most optimal condition for maximizing gas yield from fast pyrolysis. Therefore, single-particle-based CFD simulation can be used as an effective tool to understand pyrolysis mechanisms and optimize process parameters in a screw reactor.

Micro, Small, and Medium Enterprises (MSMEs) play a vital role in driving economic growth; however, their production activities frequently face uncertainty in achieving predetermined targets. Such uncertainty arises from fluctuating market demand, delays in raw material supply, labor limitations, variations in processing time, and other technical constraints. Conventional deterministic production planning methods often fail to capture these real-world risks and variations, leading to less accurate and suboptimal decisions. Therefore, a more adaptive analytical approach that incorporates probability and uncertainty is required. This study aims to analyze the probability of achieving MSME production targets using the Monte Carlo Simulation method. This method models random production conditions by generating data based on probability distributions derived from historical records. Simulations are repeated through numerous iterations to estimate possible variations in production output and measure the likelihood of meeting targets. The results indicate that Monte Carlo simulation provides more realistic and comprehensive production forecasts compared to traditional planning approaches. By understanding both the probability of success and potential risks, MSMEs can design adaptive strategies, optimize resource allocation, manage inventory more effectively, and improve overall production planning accuracy to ensure long-term business sustainability in a dynamic environment.

The automotive industry requires fast and accurate sales services, particularly in vehicle credit simulation processes. At Mazda dealerships, credit simulations are still commonly conducted using conventional tools such as printed installment tables or static PDF documents, which often cause delays and calculation errors. This study aims to design and develop a mobile-based vehicle credit simulation application using the Human-Centered Design (HCD) approach and the Flutter framework. The HCD method was implemented through the inspiration, ideation, and implementation stages to ensure that the application meets the real needs of Mazda sales representatives. The application supports flexible credit calculations based on vehicle on-the-road price, down payment, loan tenor, interest rate, and insurance schemes, including All Risk and combination insurance. Usability testing results show that the proposed application significantly improves calculation speed, accuracy, and overall user experience compared to conventional methods. Therefore, the application effectively supports sales performance, minimizes human error, and enhances professionalism in automotive sales services.

Penelitian ini bertujuan untuk merancang dan merealisasikan antena mikrostrip patch berbentuk segitiga (triangular) yang bekerja pada frekuensi 1800 MHz, sebagai penguat jaringan internet di kawasan Kebun Raya Balikpapan. Lokasi tersebut diketahui memiliki kualitas sinyal yang kurang baik untuk beberapa provider. Antena yang dirancang menggunakan dua konfigurasi, yaitu MIMO 8x8 dengan teknik pencatuan langsung dan array 8x1, yang kemudian disimulasikan menggunakan CST Studio Suite 2019 dan diuji performansinya menggunakan metode Speedtest. Hasil simulasi menunjukkan bahwa antena 8x8 memiliki nilai VSWR sebesar 1,50, return loss -12,96 dB, dan gain 4,06 dBi dengan pola radiasi omnidirectional. Sementara itu, konfigurasi 8x1 array menunjukkan nilai VSWR 1,24, return loss -19,21 dB, dan gain 6,46 dBi, juga dengan pola radiasi omnidirectional. Hasil pengujian di lapangan dengan tiga kondisi tanpa antena eksternal, antena MIMO dan antena array 8x1 didapatkan hasil bahwa antena array 8x1 memberikan kecepatan unduh tertinggi mencapai 17,227 Mbps, unggah 4,072 Mbps, Jitter 34,9 ms  dan packet loss 14,18 % sedangkan antena MIMO 8x8 memberikan kecepatan unduh tertinggi mencapai 13,77 Mbps, unggah 2,462 Mbps, Jitter 49,9 ms  dan packet loss 18,43%. Kesimpulannya, kedua jenis antena eksternal yakni MIMO 8x8 dan array 8x1 mampu meningkatkan performa jaringan secara signifikan dan dapat menjadi solusi efektif untuk daerah dengan sinyal lemah. Antena ini diharapkan dapat memberikan kontribusi terhadap akses internet yang lebih stabil di area public yang sangat luas.

The oil and gas industry plays a crucial role in meeting global energy needs, with crude oil from production wells being the primary product of upstream operations. Prior to further processing, crude oil requires pretreatment at the production site, one of the key stages being phase separation using a flash separator. This study examines the effect of variations in cooling temperature on the performance of liquid phase separation and energy requirements in the flash separation process of light hydrocarbons. The analysis was conducted through process simulation using Aspen HYSYS version 14.2 with the Peng Robinson property package. The feed stream had a mass rate of 10,000 kg per hour, a temperature of 50°F, and atmospheric pressure, with compositions of ethane, propane, isobutane, and normal butane. The process configuration included compression, cooling, and phase separation in a flash separator at a constant pressure of 50 psia. Variations in cooling temperature were applied at 20, 10, and 0°C. The simulation results indicated a thermodynamic critical point at 10°C. At 20°C, no liquid phase was formed, while at 10°C, significant liquid yield was obtained with moderate energy consumption. Lowering the temperature to 0°C dramatically increases liquid recovery, but the cooling energy requirement also increases sharply. Sensitivity analysis confirms a strong inverse relationship between temperature and condensation yield, as well as a surge in energy consumption at low temperatures. The optimal operating condition is set at 10°C, providing a balance between separation efficiency and energy efficiency in accordance with sustainable manufacturing principles.

The disparity in the quality of rehabilitation services across regional work units presents a significant challenge to effective public management. This study aims to bridge the gap between problem diagnosis and policy prediction by proposing a hybrid, data-driven approach. We integrate K-Means Clustering to map the current state of service quality and Stochastic Simulation to predict the impact of strategic interventions. Using the 2024 Public Satisfaction Index (IKM) dataset from the National Narcotics Agency (BNN), the K-Means algorithm initially identified 26 work units (15.7%) in the "Red Zone" (critical performance), highlighting urgent areas for improvement. Next, a stochastic simulation modeling a "Directed Priority Intervention" scenario was run. The results predicted a significant structural shift in the distribution of service quality, characterized by an 80.8% decrease in critical units (down to 5 units) and a 71.8% increase in excellent performing units (up to 67 units). These findings validate that the integration of clustering and simulation provides a comprehensive framework for evidence-based decision-making, enabling policymakers to optimize resource allocation and efficiently accelerate national service standardization.

This study aims to simulate the M/M/1 queueing system using Python through a Modeling and Simulation approach supported by the Discrete-Event Simulation (DES) method. The objective of the research is to analyze key performance indicators of queueing behavior, including arrival time, service time, waiting time, queue length, and server utilization. The methodology employs DES, which models system behavior based on discrete events such as customer arrivals, service initiation, and service completion. The simulation generates stochastic arrival and service times using Poisson and exponential distributions, respectively. The results indicate that the DES-based M/M/1 simulation accurately reflects theoretical queueing behavior, showing increases in waiting times and queue lengths when arrival rates approach service rates, while server utilization corresponds to system load intensity. The findings demonstrate that DES is an effective approach for analyzing queue performance and can be extended to more complex models such as multi-server systems, priority queues, and predictive simulations using artificial intelligence.

Proyek Trade Mall di Jabodetabek sebagai bagian dari bisnis properti merupakan proyek yang memiliki tingkat penyerapan pasar tertinggi diantara proyek properti komersial lainnya seperti apartemen, hotel, perumahan, kantor, dan industri. Tujuan dari penelitian ini untuk mengevaluasi strategi pra pengembangan proyek trade mall dalam rangka meningkatkan profitabilitas dan daya saing developer di wilayah Jabodetabek serta mengidentifikasi variabel-variabel yang menentukan tingkat profitabilitas dari pra pengembangan proyek Trade Mall, menyusun model system dynamics yang dapat menggambarkan pengaruh dari supply dan demand pengembangan proyek Trade Mall terhadap kinerja daya saing developer, membuat rekomendasi tindakan perbaikan terhadap penyebab terjadinya penurunan tingkat profitabilitas dan kinerja daya saing developer. Metode penelitian yang digunakan adalah analisis arsip dan survei. Kemudian data yang telah diperoleh dianalisa dengan menggunakan analisa statistik dan system dynamics. Hasil penelitian menunjukkan ada dua faktor utama yang berpengaruh terhadap tingkat profitabilitas proyek, yaitu harga jual dan tingkat penjualan, gap pertumbuhan Trade Mall yang diperoleh dari simulasi supply & demand. Serta rekomendasi tindakan perbaikan yang dilakukan terhadap penyebab penurunan profitabilitas dan daya saing developer.

Air bersih merupakan kebutuhan pokok yang sangat penting bagi kehidupan manusia. Seiring dengan pertambahan dan perkembangan penduduk kebutuhan akan air bersih juga semakin meningkat, untuk itu perlu dilakukan analisis terhadap sistem jaringan perpipaan eksisting. Penelitian ini dilakukan dengan bantuan Pamsimas Sendang Lumintu Desa Sendangkulon Kecamatan Kangkung yang bertujuan untuk mengetahui kondisi eksisting sistem jaringan perpipaan Pamsimas Sendang Lumintu untuk tahun 2024 , mengetahui berapa besar kebutuhan air yang dibutuhkan untuk memenuhi pertumbuhan penduduk sampai dengan tahun 2039,  dan menganilisi kondisi eksisting sistem jaringan perpipaan Pamsimas Sendang Lumintu untuk tahun 2039. Metode yang digunakan dalam penelitian ini adalah dengan mengumpulkan data sekunder lalu menganalisis data tersebut dengan program EPANET 2.0 sehingga didapatkan hasil simulasi. Hasil simulasi menunjukan bahwa pada tahun 2024 besar debit kebutuhan rata-rata yaitu sebesar 16,27 liter/detik, kebutuhan harian maksimum 17,90 liter/detik dan kebutuhan jam puncak 24,40 liter/detik. Sedangkan untuk tahun 2039 besar debit kebutuhan rata-rata yaitu sebesar 20,92 liter/detik, kebutuhan harian maksimum 23,01 liter/detik dan kebutuhan jam puncak 31,38 liter/detik. Kondisi hidrolis eksisting sistem jaringan Pamsimas Sendang Lumintu Kecamatan Sendangkulon masih ada yang tidak sesuai kriteria. Kriteria yang dianalisa adalah sisa tekan dan kecepatan air. Pada jam puncak terdapat beberapa titik yang menghasilkan sisa tekan kurang dan kecepatan dibawah kriteria

Salah satu bentuk pengolahan limbah menjadi energi yang berasal dari limbah padat perkotaan adalah sampah bahan bakar turunan atau Refuse Derived Fuel (RDF). Terdapat berbagai teknologi pengeringan yang biasanya digunakan untuk pengeringan RDF. Contoh penerapannya adalah oil tube rotary dryer sebagai alternatif dari steam tube rotary dryer karena sejumlah alasan utama. Pertama, penggunaan oil engine sebagai material penghantar panas tidak membutuhkan tekanan tinggi seperti pada steam tube rotary dryer sehingga komposisi desain yang tidak serumit steam tube rotary dryer. Penelitian ini dilakukan untuk mengetahui perancangan dan analisis kekuatan struktur mesin oil tube rotary dryer yang dilakukan melalui software Solidworks. Cara kerja mesin dimulai dari pemanasan thermal oil di unit pemanas hingga mencapai suhu operasi yang diinginkan. Oil panas kemudian disirkulasikan secara tertutup ke dalam tube di dalam drum pengering. Pada saat yang sama, RDF dengan kadar air awal 55% dimasukkan melalui inlet housing ke dalam shell. Suhu yang bekerja pada oil untuk memanaskan sekitar 150°C, jumlah total tube 65 buah berdiameter 1,25 inch, dan panjang pipa 10 m yang tersusun di dalam shell. Hasil analisis struktur mesin oil tube rotary dryer berdasarkan simulasi didapatkan stress (von mises) dengan nilai tertinggi 9,371 × 108 N/m^2. Sedangkan nilai terendah 9,628 × 103 N/m^2. Nilai tertinggi dari hasil simulasi tersebut terjadi pada sudut tajam bagian support roller yang tidak terdapat kontak, sehingga hal ini dapat diabaikan karena merupakan stress singularity. Hasil simulasi displacement  dengan  nilai tertinggi 1,026 × 101 N/m^2. Sedangkan nilai terendah 1,000 × 10-30 N/m^2. Nilai tertinggi dari hasil simulasi tersebut merupakan penerapan dari gaya centrifugal yang terjadi pada drum/shell rotary. Hasil simulasi Safety factor yaitu mengacu pada rata-rata probe result adalah 2,3. Sehingga dari hasil simula

Oil spills in port waters are one of the serious threats to the marine environment and port operations. This study aims to simulate the level of preparedness of oil spill response equipment available at the Oil Base Jetty of PT Pertamina Port Panjang Lampung. Simulations were conducted based on three scenarios, namely a medium-scale spill at Jetty 1 (10,000 liters), a large spill at Jetty 2 (50,000 liters), and a combined maximum spill (60,000 liters). Evaluation was conducted on three main types of equipment: oil boom, skimmer, and dispersant, by considering their effectiveness and adequacy based on the Minister of Transportation Regulation No. PM 58 Year 2013 and guidelines from the International Maritime Organization (IMO). The simulation results show that the oil boom has high effectiveness in all scenarios, demonstrating maximum readiness in the initial containment of the spill. However, the effectiveness of skimmer and dispersant is still low, especially in large-scale scenarios, so they are not able to handle the spill volume optimally. From these results, it can be concluded that although the containment aspect is adequate, there is still a need for improvement in spill recovery facilities, both in terms of the number of units and equipment capacity. This research is expected to be a reference in planning the strengthening of the oil spill emergency response system in the port area.

This study aims to design a blanking die used for mass-producing mobile phone holders while prioritizing efficiency and dimensional accuracy. The die set developed includes key components such as the punch, die, stripper, guide post, and fastening bolts. The product produced has dimensions of 138 × 63 × 2 mm and uses ST 37 steel as the raw material. Based on calculations, the required blanking force is 129,000 kN, which is considered safe for the production process. The design also accounts for an optimal clearance of 0.083 mm and a die thickness of 35 mm to effectively withstand the working load. Simulations using stress analysis methods reveal that the von Mises stress distribution on both the punch and die remains below the elastic limit of SKD11 material. The maximum stress on the punch is recorded at 2.437 × 10⁵ N/m², while on the die it reaches 5.153 × 10⁵ N/m², both well below the yield strength of SKD11, which is 2.918 × 10⁸ N/m², indicating that these components operate safely without the risk of plastic deformation. To strengthen the construction, the stripper is designed with a thickness of 12 mm, and the addition of four SCM435 bolts is recommended to improve system stability. This die design is verified through manual calculations and Finite Element Analysis (FEA) to ensure its reliability. Overall, the findings of this study demonstrate that the designed blanking die can support mass production with high precision, optimal structural strength, and long-term durability.

The manufacturing industry in Indonesia has experienced significant growth. This increase has also impacted the demand for motorcycle spare parts. Currently, brake pads are composed of asbestos, which makes them prone to overheating and failure when reaching high friction temperatures. Therefore, an alternative brake pad material is an organic material mixed with coconut shell powder and bamboo fiber. This study aims to analyze the wear and hardness levels of motorcycle brake pads made from coconut shell powder and bamboo fiber. The study used varying ratios of coconut shell powder, bamboo fiber, and epoxy resin: 40:30:30, 35:35:30, and 30:40:30. Eighteen specimens were tested. Wear testing was performed using an Ogoshi Wear Tester, while hardness testing was performed using a Brinell hardness tester. The test results showed that the smallest wear rate on brake pads with variations of 40% coconut shell powder, 30% bamboo fiber and 30% epoxy resin was 0.001107984 mm3/kg.m. The highest hardness level was also in the variation of 40% coconut shell powder, 30% bamboo fiber and 30% epoxy resin at 63,0024 kg/. So it can be concluded that the greater the percentage of coconut shell powder and the smaller the percentage of bamboo fiber, the lower the wear rate. If the greater the percentage of coconut shell powder and the smaller the percentage of bamboo fiber, the higher the hardness level. So it can be concluded that a good brake pad variation is a variation of 40% coconut shell powder, 30% bamboo fiber and 30% epoxy resin.

The use of buck converters as DC step-down voltage regulators is increasingly important in various power electronics applications. However, the quality of the output voltage is often disturbed by the presence of ripple, which is influenced by variations in the duty cycle. This study aims to analyze the effect of duty cycle variations on the output voltage and ripple of a buck converter using MATLAB/Simulink simulation. The method used is quantitative simulation by varying the duty cycle from 10% to 90% in a buck converter circuit with fixed parameters: input voltage 30 V, switching frequency 40 kHz, inductor 176.25 μH, and capacitor 44.33 μF. The simulation results show that the output voltage is proportional to the duty cycle, increasing from 3.245 V at D=10% to 26.82 V at D=90%. The highest ripple occurred at D=40% with a value of 0.07 V, while the lowest ripple was at D=50% with a value of 0.0003 V. These findings indicate the existence of an optimal operating point where the system works most stably. This study provides practical guidance in designing efficient and stable buck converters for applications such as battery charging and renewable energy systems.

Kegiatan pengabdian ini bertujuan untuk meningkatkan literasi dan keterampilan perencanaan keuangan bagi pelaku industri rumahan, khususnya penjahit perempuan dan ibu rumah tangga di sentra konveksi Desa Kalitengah, Kecamatan Wedi, Klaten. Permasalahan rendahnya literasi keuangan, tidak adanya pencatatan keuangan, serta tumpang tindih antara keuangan pribadi dan usaha menjadi hambatan utama dalam pengambilan keputusan finansial dan keberlanjutan usaha. Program ini dilaksanakan melalui pendekatan edukatif dan partisipatif yang meliputi penyuluhan interaktif, pelatihan pencatatan keuangan, simulasi perencanaan anggaran, diskusi kelompok, serta pendampingan individual. Materi disampaikan secara kontekstual menggunakan bahasa sehari-hari dan narasi kehidupan nyata, serta mengintegrasikan nilai kearifan lokal seperti prinsip “kembali ke akar”. Hasil evaluasi menunjukkan peningkatan pemahaman peserta terhadap pentingnya pencatatan pemasukan-pengeluaran, penyusunan anggaran rumah tangga, serta perubahan sikap terhadap konsumsi dan manajemen keuangan keluarga. Kegiatan ini terbukti efektif dalam mendorong transformasi perilaku keuangan yang lebih bijak dan dapat direplikasi dalam pemberdayaan ekonomi rumah tangga berbasis komunitas

Breast milk (ASI) is the primary and natural food for newborns, providing the necessary energy and nutrients from birth to six months of life, promoting optimal growth and development. However, according to information obtained, about 30% of mothers face challenges in breastfeeding, particularly during the first few days after delivery. To address this issue, interventions such as breast care and oxytocin massage can stimulate breast milk production and prevent issues like mastitis. Oxytocin massage helps stimulate the milk ejection reflex, while breast care ensures the cleanliness of the breasts, making it easier for the baby to latch. The aim of this community service activity is to enhance mothers' knowledge through an educational program focused on oxytocin massage and breast care to improve milk production in postpartum mothers. The method used for this activity is an interactive educational session using tools like PowerPoint and leaflets, followed by a Q&A session and discussion. The evaluation was conducted through oral questioning, as well as by observing participants' enthusiasm during the session. The expected outcome of this activity is to provide mothers with practical knowledge and skills on breast care and stimulating breast milk production, ultimately supporting successful exclusive breastfeeding.