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Analisis Perbandingan Kinerja ESD Untuk Tipe Mewis Duct, PBCF, Fins Pada Kapal Oil & Product Tanker 17.500 DWT Menggunakan Metode Computational Fluid Dynamics
No full textDalam rangka menanggapi regulasi efisiensi energi dan pengurangan emisi gas rumah kaca dari International Maritime Organization (IMO), penelitian ini mengevaluasi kinerja beberapa jenis Energy Saving Devices (ESD) — yaitu Mewis Duct, Propeller Boss Cap Fins (PBCF), Pre- Swirl Fins dan Twisted Fins — yang diaplikasikan pada kapal Oil & Product Tanker 17.500 DWT. Penelitian dilakukan dengan metode Computational Fluid Dynamics (CFD) menggunakan perangkat lunak ANSYS Fluent untuk mensimulasikan aliran fluida di sekitar kapal dan propeller. Simulasi terdiri dari tiga tahap utama: Open Water Test, Resistance Test, dan Self-Propulsion Test. Hasil simulasi menunjukkan bahwa setiap tipe ESD memberikan pengaruh yang berbeda terhadap efisiensi propulsi kapal, tahanan total, serta konsumsi energi. Mewis Duct menunjukkan peningkatan efisiensi tertinggi, diikuti oleh PBCF dan Twisted Fins. Temuan ini diharapkan dapat menjadi referensi dalam pemilihan teknologi ESD yang optimal untuk meningkatkan performa kapal dan mendukung pemenuhan standar efisiensi energi maritim global.
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In response to international regulations on energy efficiency and greenhouse gas emission reduction set by the International Maritime Organization (IMO), this study evaluates the performance of several types of Energy Saving Devices (ESDs) — namely Mewis Duct, Propeller Boss Cap Fins (PBCF), and Twisted Fins — applied to a 17,500 DWT Oil & Product Tanker. The research was conducted using Computational Fluid Dynamics (CFD) simulations in ANSYS Fluent to model fluid flow around the ship hull and propeller. The simulations consisted of three main stages: Open Water Test, Resistance Test, and Self-Propulsion Test. Results showed that each ESD type had a distinct impact on propulsion efficiency, total resistance, and energy consumption. Among the tested configurations, the Mewis Duct demonstrated the highest efficiency improvement, followed by PBCF and Twisted Fins. These findings can serve as a reference for selecting optimal ESD technologies to enhance ship performance and support compliance with global maritime energy efficiency standards
Integrated Geophysical Acquisition And Processing For Groundwater Exploration
No full textThis study focuses on integrating resistivity and seismic methods for groundwater exploration in Kinta Valley, Perak, specifically at Universiti Teknologi PETRONAS. Groundwater is a very important resource which require appropriate geophysical acquisition to explore. The resistivity method, using the Wenner-Schlumberger configuration, was chosen to map the variations in resistivity of the subsurface, identifying water-bearing zones. Simultaneously, seismic reflection methods were applied to delineate geological boundaries and structures. The acquisition layout and parameters for both methods were designed and optimized to improve the quality of the data, though limitations such as limited available space and noise were encountered. Appropriate data processing workflows have been conducted to improve subsurface imaging including inversion modelling for resistivity and stacking for seismic data. The resistivity pseudosection that showed low-resistivity zones indicates presence of water-saturated formations, while seismic section showed a structural feature despite weak reflections due to acoustic impedance. A reduction in velocity trend were observed during velocity picking which was interpreted due to pile of gravel. Integration of these two methods have shown their reciprocal strengths, which the resistivity method were used to validate near-surface seismic anomalies, helping in interpretation. This study highlights the implications of integrating these methods for groundwater exploration, which cross-validation can be used to improve processing workflow. However, integrated interpretation could not be conducted due to discrepancy in depth of acquisition result. Recommendations for future work in this area are minimizing seismic trigger delays, extending the resistivity survey coverage, and using higher-energy seismic sources to improve the quality of the data.
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Studi ini berfokus pada integrasi metode resistivitas dan seismik untuk eksplorasi air tanah di Kinta Valley, Perak, khususnya di Universiti Teknologi PETRONAS. Groundwater merupakan sumber daya yang sangat penting dan memerlukan akuisisi geofisika yang tepat untuk dieksplorasi. Metode resistivitas, menggunakan konfigurasi Wenner-Schlumberger, dipilih untuk memetakan variasi resistivitas bawah permukaan guna mengidentifikasi water-bearing zone. Secara bersamaan, metode seismic reflection diterapkan untuk menentukan batas dan struktur geologi. Desain tata letak akuisisi dan parameter untuk kedua metode dioptimalkan untuk meningkatkan kualitas data, meskipun terdapat keterbatasan seperti ruang yang terbatas dan noise. Alur kerja pemrosesan data yang sesuai telah dilakukan untuk meningkatkan pencitraan bawah permukaan, termasuk inversion modelling untuk data resistivitas dan stacking untuk data seismik. Pseudosection resistivitas menunjukkan zona low-resistivity yang mengindikasikan keberadaan water-saturated formation, sementara seismic section menunjukkan suatu fitur struktur meskipun terdapat weak reflections akibat acoustic impedance. Teramati tren penurunan velocity selama velocity picking yang diinterpretasikan disebabkan oleh tumpukan gravel. Integrasi kedua metode ini menunjukkan keunggulan saling melengkapi, di mana metode resistivitas digunakan untuk memvalidasi anomali seismik near-surface, sehingga membantu dalam interpretasi. Studi ini menyoroti implikasi integrasi kedua metode untuk eksplorasi air tanah, di mana cross-validation dapat digunakan untuk meningkatkan workflow pemrosesan. Namun, interpretasi terintegrasi tidak dapat dilakukan karena perbedaan kedalaman hasil akuisisi. Rekomendasi untuk pekerjaan selanjutnya di area ini adalah meminimalkan seismic trigger delays, memperluas cakupan survei resistivitas, dan menggunakan seismic sources berenergi lebih tinggi untuk meningkatkan kualitas data
Pemilihan Media Co-Firing Pltu Batubara Menggunakan Metode AHP-TOPSIS: Studi Kasus Pembangkitan Listrik PT.XYZ
No full textPenilitian tesis berjudul “Pemilihan Media Co-Firing Pltu Batubara Menggunakan Metode AHP-TOPSIS: Studi Kasus Pembangkitan Listrik PT.XYZ” bertujuan untuk bertujuan untuk melakukan analisa terkait pemilihan media co-firing PLTU batu bara. Batubara, merupakan salah satu sektor unggulan dalam pembangkitan energi. Dalam proses penambangannya, perusahaan membutuhkan tenaga listrik untuk kegiatan operasional. Untuk mendukung program pemerintah terkait energi terbarukan, perusahaan berencana melakukan sistem pembakaran cofiring dengan bahan baku yang ada di daerah sekitar. Pada penilitian ini, digunakan metode MCDM (Multi-Criteria Dicision Making) dengan melakukan pengolahan data wawancara kepada PT.XYZ sebagai objek penelitian serta dilakukan telaah regulasi Provinsi Sumatra Selatan, sumber biomassa potensial sebagai media co-firing di sekitar wilayah operasi PT. XYZ. Untuk melihat telaah gap analisa
dilakukan plot dengan metode SWOT. Pada penilitian ini, bertujuan untuk membantu merumuskan sumber daya energi terbarukan potensial dan memiliki ketersediaan cukup sehingga PT. XYZ mampu melakukan program co-firing dengan tetap mencukupi kebutuhan energi listrik harian. Dari hasil penelitian didapatkan hasil wood chip kaliandra merah 84%, tandan kosong kelapa sawit 66%, sekam padi 44% dan bagasse tebu sebesar 11%
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The thesis research entitled "Selection of Coal Co-Firing Media Using AHP-TOPSIS Method: Case Study of PT XYZ Electricity Generation" aims to analyse the selection of co-firing media for coal-fired power plants. Coal is one of the leading sectors in energy generation. In the mining process, the company needs electricity for operational activities. To support government programmes related to renewable energy, the company plans to conduct a co-firing combustion system with raw materials in the surrounding area. In this research, the MCDM (Multi-Criteria Dicision Making) method is used by processing interview data to PT.XYZ as the object of research and reviewing South Sumatra Province regulations, potential biomass sources as co-firing media around the PT.XYZ operating area. To see the gap analysis, a plot was carried out using the SWOT method. In this research, it aims to help formulate potential renewable energy resources and have sufficient availability so that PT XYZ is able to carry out a co-firing programme while still
meeting daily electrical energy needs. From the results of the study, it was found that the results of red calliandra wood chips were 84%, palm empty fruit bunches were 66%, rice husks were 44% and sugar cane bagasse was 11%
Analisis Data Penggunaan Block Storage Untuk Rekomendasi Penyeimbangan Beban Kerja Aplikasi Telekomunikasi Menggunakan Klasterisasi
No full textPerkembangan industri teknologi informasi menghadirkan solusi infrastruktur penyimpanan data seperti block storage. PT XYZ, perusahaan telekomunikasi, menggunakan 32 server block storage untuk memproses data aplikasi. Pertumbuhan data dan variasi aplikasi menyebabkan server block storage beroperasi dengan kemampuan pemrosesan yang beragam. Server block storage ini krusial untuk meningkatkan mutu layanan aplikasi. Meskipun beban kerja block storage dapat diukur, PT XYZ belum memiliki alat untuk menganalisis data performanya. Oleh karena itu, diperlukan metoda analisis penggunaan server block storage untuk mengetahui beban kerja aplikasi telekomunikasi. Penelitian ini mengusulkan pendekatan klasterisasi untuk menganalisis server block storage PT XYZ berdasarkan profil kinerja, bertujuan mengkategorikannya ketingkatan beban kerja rendah, menengah, dan tinggi. Secara spesifik, dilakukan analisis komparatif antara metode K-Means dan DBSCAN. Lalu dilakukan evaluasi kinerja klasterisasi menggunakan metoda ground truth dengan membandingkan keluarannya terhadap penelitian sebelumnya. Dataset diambil dari data beban kerja 32 server block storage yang mencakup metrik IOPS (IOs/Sec), Service Time (ms), dan Bandwidth (KBs/Sec) selama periode 1.5 tahun. Metode Klasterisasi K-Means dan DBSCAN diterapkan pada dataset ini untuk membentuk klaster server. K-Means dengan algoritma partisional dan mengelompokkan server ke dalam K klaster (misal, K=3 untuk tiga tingkatan kinerja) berdasarkan kedekatan karakteristik. DBSCAN dengan algoritma berbasis kepadatan untuk mengidentifikasi klaster berbentuk fleksibel dan mendeteksi outlier. Kualitas hasil klasterisasi divalidasi secara eksternal dengan membandingkannya terhadap ground truth. Performa setiap algoritma diukur melalui tingkat akurasi, yaitu dengan memeriksa kesesuaian label klaster pada setiap ID server. Lalu dilakukan perbandingan klaster mana yang paling akurat. Hasil Perbandingan akurasi klaster menunjukkan DBSCAN yang paling akurat. Hasil analisis klusterisasi DBSCAN mampu digunakan untuk analisis kinerja server block storage dengan klasterisasi beban kerja yang terbagi menjadi 3 yaitu klaster beban kerja rendah, klaster beban kerja menengah dan klaster beban kerja tinggi. Kasterisasi ini diharapkan dapat memberikan rekomendasi terhadap penyeimbangan beban kerja guna mendukung optimalisasi penggunaan sumber daya TI secara lebih efisien. =====================================================================================================================================
The development of industrial information technology presents data storage infrastructure solutions such as block storage. PT XYZ, a telecommunications company, uses 32 block storage servers to process application data. Data growth and application variations cause block storage servers to operate with diverse processing capabilities. These block storage servers are crucial for improving application service quality. Although block storage performance can be measured, PT XYZ does not yet have tools to analyze its performance data. Therefore, it is necessary to analyze the block storage server workload for application load shifting recommendations. This research proposes a clustering approach to analyze PT XYZ's block storage servers based on performance profiles, with the aim of categorizing them into low, medium, and high workload levels. Specifically, a comparative analysis between the K-Means and DBSCAN methods was conducted. Then, the clustering performance was evaluated using the ground truth method by comparing the output with previous studies. The dataset was retrieved from 32 server block storage systems, encompassing metrics such as IOPS (IOs/s), service time (ms), and bandwidth (KBs/s), over a span of 1.5 years. The K-Means and DBSCAN clustering methods were applied to this dataset to form server clusters. K-Means uses a partitioning algorithm and groups servers into K clusters (e.g., K=3 for three performance levels) based on characteristic proximity. DBSCAN uses a density-based algorithm to identify flexible clusters and detect outliers. The quality of the clustering results was externally validated by comparing them to the ground truth. The performance of each algorithm was measured through accuracy levels, by examining the cluster label consistency for each server ID. Then do the cluster comparison. The outcomes of the cluster accuracy comparison demonstrate that DBSCAN is the most precise. The results of the DBSCAN clustering analysis can be used to analyze the performance of block storage servers with workloads divided into three clusters: low workload cluster, medium workload cluster, and high workload cluster. It is anticipated that this clustering will yield recommendations for workload balancing, thereby facilitating more efficient optimization of IT resource utilization
Pemetaan Sentimen Media dan Hubungan Entitas dalam Berita Teknologi Pertanian
No full textDigitalisasi pertanian memiliki perkembangan yang begitu pesat dengan adanya dukungan teknologi seperti Big Data, Internet of Things, dan Artificial Intelligence yang didorong oleh peran media sebagai pembentuk opini publik. Penelitian ini mengintegrasikan Machine Learning, dan Knowledge Graph untuk memetakan sentimen dan relasi antar entitas dalam 1.295 artikel oleh BBC, The Guardian, The Independent, dan Reuters, pada publikasi 2013-2025. Hasil klasifikasi menunjukan model BERT dengan Random Forest unggul dengan hasil akurasi 92% dan F1-macro rata-rata 87.2% menjadi baseline terbaik dibanding dengan BERT + SVM (91%), dan BERT+XGBoost (91%). Pada tahap pemetaan relasi, triples hasil NER dan Relation Extraction dibangun pada Knowledge Graph, kemudian dieksplorasi menggunakan Graph Convolutional Network. Klaster K-Means menunjukkan lebih dari 70% relasi masih berupa open triad, menandakan celah koneksi. Enrichment diikuti pemisahan komunitas Louvain meningkatkan modularitas menjadi 0,45 dan membentuk empat komunitas yang sejalan dengan enam topik utama: Food Security & Risk Management, Economic & Family Farming, Supply Chain & Trade, Technology Adoption, Climate & Environment, serta Investment & Market. Sentimen Pro mendominasi 70% pada topik ketahanan pangan, sedangkan komunitas perdagangan memuat porsi Contra tertinggi, yakni 40%. Secara keseluruhan, pendekatan gabungan KG–GCN–ML efektif memperkaya analisis sentimen berita teknologi pertanian, mengungkap pola topik sentimen sekaligus peluang perluasan relasi antar entitas untuk riset kebijakan dan strategi adopsi teknologi pertanian.
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Agricultural digitalization propelled by IoT, AI, and Big Data, and amplified by media influence is rapidly evolving. This study combines Knowledge Graphs (KG) and Machine Learning to map sentiment across 1,295 articles news from BBC, The Guardian, The Independent, and Reuters published between 2013 and 2025. The best classifier, a BERT model paired with a Random Forest, attains 92% accuracy and an 88 %F1-macro, outperforming BERT-SVM and BERT-XGBoost. For relation mapping, NER- and RE-derived triples are built into a KG and explored with a Graph Convolutional Network. Initial k-means clustering shows that over 70 % of the triads are open, revealing connectivity gaps; community enrichment with Louvain raises modularity to 0.45 and yields four communities aligned with six key topics Food Security and Risk Management; Economic and Family Farming; Supply Chain and Trade; Technology Adoption; Climate and Environment; and Investment and Market. Pro sentiment dominates food-security coverage at roughly 70 %, while trade-focused articles carry the highest Contra share, at 40 %. Overall, the integrated KG–GCN–ML framework enriches agritech sentiment analysis, unveiling topic–sentiment patterns and opportunities for expanding entity relations in policy and technology-adoption research
Fabrikasi Mixed Matrix Membran P84/Cuo@AK-ZEOLIT-Y Untuk Aplikasi Pemisahan CO2 / CH4
No full textPenelitian ini mengembangkan membran Mixed Matrix Membrane (MMM) berbasis P84 ko-poliimida dengan filler CuO@AK-Zeolit-Y (CuO@AKZY) untuk aplikasi pemisahan gas CO₂/CH₄. Polimer P84 ko-poliimida dipilih karena selektivitas gasnya yang tinggi, namun sifat mekaniknya perlu ditingkatkan melalui variasi suhu fabrikasi. Filler CuO@AK-Zeolit-Y disintesis dengan variasi loading Cu sebesar 15, 20, 25, dan 30%. Membran neat difabrikasi pada suhu 35, 50, dan 65°C, sedangkan seluruh membran MMM difabrikasi pada suhu 35°C dengan komposisi filler sebesar 1,5% b/b. Karakterisasi dilakukan menggunakan X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy–Energy Dispersive X-Ray (SEM-EDX), Brunauer–Emmett–Teller (BET) surface area analysis, serta uji kinerja adsorpsi gas. Hasil karakterisasi XRD dan FTIR menunjukkan bahwa membran Neat-35°C memiliki struktur yang lebih amorf dan permeabel dibandingkan Neat-50°C akibat terjadinya thermally induced relaxation. Uji adsorpsi menunjukkan bahwa filler dengan penambahan 20% Cu memiliki kapasitas adsorpsi tertinggi dan dispersi Cu yang merata. Material ini memiliki luas permukaan BET sebesar 386,58 m²/g. Namun, kinerja pemisahan gas terbaik diperoleh pada membran MMM dengan penambahan Cu 25%, yang menunjukkan selektivitas H2/CO2 sebesar 3,25 dan 1,53 untuk CH4/CO2. Hasil ini menunjukkan bahwa kombinasi rasio Cu yang tepat dan pengaturan suhu fabrikasi dapat meningkatkan efisiensi dan stabilitas membran untuk aplikasi pemisahan gas.
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=This study developed a Mixed Matrix Membrane (MMM) based on P84 co-polyimide with CuO@AK-Zeolite-Y (CuO@AKZY) filler for CO₂/CH₄ gas separation applications. P84 co-polyimide polymer was chosen due to its high gas selectivity, but its mechanical properties need to be improved through variations in fabrication temperature. CuO@AK-Zeolite-Y filler was synthesized with variations in Cu addition of 15, 20, 25, and 30%. The pure membrane was fabricated at 35, 50, and 65°C, while all MMM membranes were fabricated at 35°C with a filler composition of 1.5% w/w. Characterization was performed using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy–Energy Dispersion X-ray (SEM-EDX), Brunauer–Emmett–Teller (BET) surface area analysis, and gas adsorption performance tests. The XRD and FTIR characterization results showed that the Neat-35°C membrane had a more amorphous and permeable structure than the Neat-50°C membrane due to thermally induced relaxation. The adsorption test showed that the filler with 20% Cu addition had the highest adsorption capacity and uniform Cu dispersion. This material had a BET surface area of 386.58 m²/g. However, the best gas separation performance was obtained in the MMM membrane with 25% Cu addition, which showed a selectivity of 3.25 for H2/CO2 and 1.53 for CH4/CO2. These results indicate that the combination of appropriate Cu ratio and fabrication temperature settings can improve the efficiency and stability of the membrane for gas separation applications
Implementasi Kontrol PID Untuk Mengatur Suhu Tangki Penampung Gelatin
No full textKetidakstabilan suhu dalam proses penyimpanan gelatin dapat menurunkan viskositas dan kekuatan gel, yang berdampak langsung terhadap mutu kapsul farmasi. Penelitian ini mengusulkan sistem pengendalian suhu berbasis mikrokontroler ESP32 dengan metode kontrol Proportional-Integral-Derivative (PID) sebagai solusi terhadap kelemahan sistem on-off sederhana yang digunakan di PT Kimia Farma Tbk Plant Watudakon. Sistem dirancang menggunakan sensor thermocouple type-K dan modul MAX6675 untuk pembacaan suhu, driver PWM berbasis MOSFET ME15N10G untuk penguatan sinyal, serta Solid State Relay (SSR) 3 fasa yang berfungsi sebagai saklar elektronik untuk mengatur penyambungan arus 3 fasa ke immersion heater berdaya 6000 W secara otomatis berdasarkan sinyal dari ESP32. Parameter PID ditentukan menggunakan metode Ziegler–Nichols tipe 1 dan disempurnakan melalui tuning manual, dengan nilai akhir Kp = 2,20, Ki = 0,003, dan Kd = 106,5. Sistem dilengkapi antarmuka HMI Nextion, indikator LED suhu, alarm buzzer, proteksi suhu tinggi, serta pencatatan suhu otomatis ke Google Spreadsheet melalui Wi-Fi sebagai bagian dari sistem IoT. Hasil pengujian menunjukkan sistem mampu menjaga kestabilan suhu pada berbagai setpoint. Pada setpoint 55 °C, diperoleh overshoot sebesar +1,39 °C , rise time sekitar 2710 detik, waktu stabil (settling time) pada detik ke-6990, serta error steady-state maksimum sebesar 2,53%. Dibandingkan sistem on-off yang menghasilkan overshoot +5,13 °C, fluktuasi suhu ±8,88 °C, dan tidak pernah mencapai kestabilan selama 8200 detik pengujian, sistem PID memberikan peningkatan signifikan dalam hal kecepatan, akurasi, dan stabilitas. Dengan demikian, sistem ini layak diterapkan pada proses industri yang memerlukan kendali suhu yang presisi, andal, dan terintegrasi secara digital.
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Temperature instability during gelatin storage can reduce viscosity and gel strength, which directly affects the quality of pharmaceutical capsules. This study proposes a microcontroller-based temperature control system using the ESP32 microcontroller with Proportional-Integral-Derivative (PID) control as a solution to the limitations of the simple on-off system currently used at PT Kimia Farma Tbk's Watudakon Plant. The system is designed using a Type-K Thermocouple sensor and MAX6675 module for temperature reading, a MOSFET-based PWM driver ME15N10G for signal amplification, and a 3-phase Solid State Relay (SSR) functioning as an electronic switch to automatically regulate the connection of 3-phase current to a 6000 W immersion heater based on signals from the ESP32. The PID parameters were determined using the Ziegler–Nichols Type 1 method and refined through manual tuning, with final values of Kp = 2.20, Ki = 0.003, and Kd = 106.5. The system is equipped with a Nextion HMI interface, LED temperature indicators, buzzer alarms, high temperature protection, and automatic temperature recording to Google Spreadsheet via Wi-Fi as part of the IoT system. Test results show that the system is capable of maintaining temperature stability at various setpoints. At a setpoint of 55°C, an overshoot of +1.39°C was observed, with a rise time of approximately 2710 seconds, a settling time at the 6990th second, and a maximum steady-state error of 2.53%. Compared to an on-off system that produced an overshoot of +5.13°C, temperature fluctuations of ±8.88°C, and never achieved stability during the 8200-second test, the PID system provides significant improvements in terms of speed, accuracy, and stability. Therefore, this system is suitable for industrial processes requiring precise, reliable, and digitally integrated temperature control
Pengaruh Loading Logam dan Rasio Komposisi Ni-Co Terhadap Karakteristik Katalis Bimetal Ni-Co/γ-Al2O3
No full textKatalis memiliki peran penting dalam bidang kimia dan industri karena dapat meningkatkan efisiensi reaksi kimia. Salah satu jenis katalis yang banyak digunakan adalah katalis berbasis nikel karena memiliki aktivitas yang tinggi dan mudah diperoleh. Namun, katalis berbasis nikel memiliki masalah utama yaitu dapat mengalami deaktivasi akibat leaching sisi aktif logam nikel dan proses sintering. Salah satu logam yang dapat digunakan untuk memodifikasi katalis berbasis nikel adalah logam kobalt. Penambahan kobalt pada katalis berbasis nikel dapat membantu mengatasi masalah deaktivasi katalis. Namun, kinerja katalis bimetal tidak hanya ditentukan oleh kehadiran logam kedua tetapi juga oleh faktor lain seperti loading logam dan rasio komposisi logam. Maka dari itu, penelitian ini dilakukan dengan tujuan untuk menganalisis pengaruh variasi loading Ni-Co dan rasio komposisi Ni-Co terhadap karakteristik katalis bimetal Ni-Co/γ-Al₂O₃ yang disintesis dengan metode wetness impregnation. Sintesis katalis ini divariasikan dengan loading 2,5; 5; 10 dan 15% b/b serta rasio komposisi Ni-Co 1:1, 3:1, dan 1:3. Analisis karakteristik dari katalis ini dilakukan dengan beberapa teknik pengujian yaitu FTIR, XRD, SEM-EDX, dan XRF. Hasil karakterisasi FTIR menunjukkan bahwa penambahan loading Ni-Co dapat mengurangi intensitas gugus -OH yang terdapat pada katalis. Kemudian, hasil karakterisasi XRD menunjukkan bahwa peningkatan loading Ni-Co pada katalis dapat ikut meningkatkan kristalinitas dan ukuran kristal pada katalis. Hasil SEM-EDX menunjukkan tekstur permukaan katalis cenderung semakin kasar dan adanya peningkatan ukuran partikel seiring dengan bertambahnya loading Ni-Co, khususnya loading kobalt. Terakhir, hasil XRF mengonfirmasi hasil analisis dengan EDX terkait rasio komposisi Ni-Co pada katalis, di mana rasio komposisi Ni-Co pada katalis Ni-Co/γ-Al2O3 sesuai dengan rasio komposisi Ni-Co yang ditargetkan pada saat sintesis. Dengan demikian, dapat disimpulkan bahwa loading dan rasio komposisi Ni-Co memiliki pengaruh pada karakteristik katalis bimetal Ni-Co/γ-Al2O3. Hasil penelitian ini menunjukkan peluang aplikasi katalis bimetal Ni-Co/γ-Al2O3 untuk beberapa reaksi seperti pada deoksigenasi biodiesel.
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Catalysts play an important role in chemistry and industry because they can increase the efficiency of chemical reactions. One type of catalyst that is widely used is a nickel-based catalyst because it has high activity and is easy to obtain. However, nickel-based catalysts have a major problem of deactivation due to nickel leaching and the sintering process. One of the metals that can be used to modify nickel-based catalysts is cobalt metal. The addition of cobalt to nickel-based catalysts can help overcome the problem of catalyst deactivation. However, the performance of bimetallic catalysts is not only determined by the presence of the second metal but also by other factors such as metal loading and metal composition ratio. Therefore, this study was conducted to analyze the effect of variations in Ni-Co loading and Ni-Co composition ratio on the characteristics of the Ni-Co/γ-Al₂O₃ bimetallic catalyst synthesized using the wetness impregnation method. The synthesis of this catalyst was varied with loading 2.5; 5; 10 and 15% b/b and Ni-Co composition ratios of 1:1, 3:1, and 1:3. Analysis of the characteristics of this catalyst was carried out using several testing techniques, namely FTIR, XRD, SEM-EDX, and XRF. The results of FTIR characterization showed that the addition of Ni-Co loading could reduce the intensity of the -OH group contained in the catalyst. Then, the results of XRD characterization showed that increasing Ni-Co loading on the catalyst could also increase the crystallinity and crystal size of the catalyst. The results of SEM-EDX showed that the surface texture of the catalyst tended to be rougher and there was an increase in particle size along with increasing Ni-Co loading, especially cobalt loading. The XRF results confirm the results of the EDX analysis about the Ni-Co composition ratio in the catalyst, which the Ni-Co composition ratio in the Ni-Co/γ-Al2O3 catalyst is in accordance with the Ni-Co composition ratio targeted during synthesis. Thus, it can be concluded that Ni-Co loading and composition ratio affect the characteristics of the Ni-Co/γ-Al2O3 bimetallic catalyst. The results of this study indicate the potential application of the Ni-Co/γ-Al2O3 bimetallic catalyst for several reactions such as biodiesel deoxygenation
Pengendalian Banjir Di Desa Jati Kecamatan Jati Kabupaten Kudus
No full textPada awal tahun 2023, Kabupaten Kudus, Jawa Tengah mengalami banjir besar yang berdampak pada 16 desa di tiga kecamatan: Jati, Undaan, dan Mejobo. Banjir ini merupakan yang terparah dibanding tahun-tahun sebelumnya, disebabkan oleh hujan deras dan topografi yang datar (0–8%). Kecamatan Jati mengalami banjir disebabkan oleh ketidakmampuan saluran drainase menampung limpasan air hujan, diperparah oleh sedimentasi, topografi datar, dan pesatnya pembangunan kawasan yang mengurangi daerah resapan air. Oleh karena itu, diperlukan penanganan terhadap saluran – saluran sekunder yang ada di kecamatan Jati untuk mengurangi risiko banjir secara efektif di kawasan ini. Sebagai upaya penanganan, Balai Besar Pemali Juana pada 2024 telah melakukan normalisasi Kali Kencing sepanjang 2,5 km, dan pembangunan kolam retensi seluas 4,8 ha. Namun, banjir masih terjadi karena pembangunan yang dapat mengurangi daerah resapan dan dapat meningkatkan limpasan permukaan.
Metode yang dilakukan pada pengendalian banjir yaitu dengan normalisasi dan kombinasi dengan Kolam Retensi, Penelitian ini bertujuan untuk mengevaluasi sistem drainase Kecamatan Jati menggunakan analisis hidrologi untuk mengetahui debit banjir rencana dan hidraulika untuk simulasi kapasitas saluran dan mengevaluasi kemampuan penampang dengan bantuan software HEC-RAS. Hasil perhitungan debit banjir rencana 10 tahun menunjukkan: LS 1 (Q = 14,884 m³/s), LS 2 (Q = 6,414 m³/s), Kota (Q = 4,162 m³/s), DK (Q = 6,821 m³/s), LS 3 (Q = 1,358 m³/s), LS 4 (Q = 1,287 m³/s), dan LS 5 (Q = 3,194 m³/s). Simulasi menunjukkan bahwa setelah normalisasi untuk peningkatan kapasitas saluran dan dari kombinasi kolam retensi, luas genangan menurun hingga ±30,07% dibandingkan kondisi eksisting.
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At the beginning of 2023, Kudus Regency in Central Java experienced a major flood that affected 16 villages across three districts: Jati, Undaan, and Mejobo. This flood was the most severe in recent years, primarily caused by heavy rainfall and the region’s flat topography (0–8%). In Jati District, flooding occurred due to the drainage system’s inability to accommodate surface runoff, worsened by sedimentation, flat terrain, and rapid urban development that reduced water infiltration areas. Therefore, it is essential to manage the secondary drainage channels in Jati District to effectively reduce the risk of flooding in this area. As part of the mitigation efforts, the Pemali Juana River Basin Organization (BBWS Pemali Juana) carried out river normalization of Kali Kencing along 2.5 km and constructed a 4.8-hectare retention pond in 2024. However, flooding still occurs due to ongoing development that reduces infiltration areas and increases surface runoff.
The flood control method applied involves a combination of river normalization and retention pond construction. This study aims to evaluate the drainage system in Jati District using hydrological analysis to determine the design flood discharge and hydraulic analysis to simulate channel capacity and assess the cross-sectional capability using HEC-RAS software. The calculated 10-year return period flood discharges are as follows: LS 1 (Q = 14.884 m³/s), LS 2 (Q = 6.414 m³/s), Kota (Q = 4.162 m³/s), DK (Q = 6.821 m³/s), LS 3 (Q = 1.358 m³/s), LS 4 (Q = 1.287 m³/s), and LS 5 (Q = 3.194 m³/s). The simulation results show that after normalization and the implementation of the retention pond, the inundated area decreased by approximately 30.07% compared to the existing conditions
Usulan Kebijakan Pengendalian Persediaan Material Untuk Kegiatan Pemeliharaan Dan Pasang Baru: Studi Kasus Di Unit Layanan Pelanggan PLN Hitu
No full textEnergi listrik merupakan kebutuhan primer bagi masyarakat sehingga keberhasilan PT PLN melalui Unit Layanan Pelanggan (ULP) dalam memenuhi layanan kebutuhan listrik pelanggan menjadi indikator ketercapaian unit. ULP Hitu merupakan satuan kerja di bawah naungan UP3 Ambon yang memberikan pelayanan pelanggan di wilayah Leihitu hingga Larike di mana kegiatan Pemeliharaan dan Pasang Baru menjadi salah satu kegiatan pelayanannya. Ketersediaan material menjadi aspek penting dalam melayani pelanggan sehingga diperlukannya pengendalian persediaan. Pada kondisi eksisting belum terdapat parameter dalam melakukan pengedalian persediaan sehingga terdapat kondisi material overstock yang menyebabkan potensi kerusakan material dan kondisi stockout yang menyebabkan pelanggan tidak dapat terlayani dengan cepat sehingga ULP mengalami potensi penjualan energi listrik yang tertunda. Penelitian ini menggunakan Analisis Fast, Slow, Nonmoving (FSN) dan Average Demand Interval (ADI) - Coefficient of Variation (CV) untuk mengetahui karakteristik dan pola permintaan material. Hasil klasifikasi material terpilih akan dilakukan perhitungan parameter persediaan dengan metode Min Max dan Simulasi Monte Carlo untuk memperoleh jumlah pemesanan material, titik pemesanan ulang, dan jumlah persediaan maksimum sehingga diperoleh total biaya persediaan dan tingkat service level. Hasil simulasi pada tiga material terpilih yaitu kWh Meter Prabayar, kWh Meter Pascabayar, dan MCB 4A menunjukkan hasil bahwa terdapat penurunan total biaya dan peningkatan service level yang cukup signifikan. Penurunan total biaya dan peningkatan service level tertinggi terdapat pada material MCB 4A yaitu penurunan total biaya sebesar 77% dan peningkatan service level sebesar 100% dari kondisi eksisting. Usulan kebijakan dengan metode Min Max dan Simulasi Monte Carlo untuk kondisi eksisting ULP saat ini memberikan keuntungan dari aspek penurunan total biaya persediaan, pengurangan biaya stockout, dan peningkatan service level.
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Electrical energy is a primary need for the community so that the ability of PT PLN Customer Service Unit (ULP) to fulfill customer electricity needs is a key performance indicator of the unit's achievement. Under the supervision of UP3 Ambon, ULP Hitu is a work unit that provides customer services in the Leihitu to Larike area where Maintenance and New Installation activities are one of its service activities. To fulfill the customer’s needs, material availability is an important aspect so that inventory control is needed. In the existing condition there is currently no parameter for inventory control, which results in overstock conditions that could lead to material damage and stockout conditions that could delay the ULP’s electricity sales by preventing customers from receiving prompt service. This study uses Fast, Slow, Nonmoving (FSN) Analysis and Average Demand Interval (ADI) - Coefficient of Variation (CV) to determine the characteristics and patterns of material demand. The results of the selected material classification will be calculated using the Min Max method and Monte Carlo Simulation to obtain the number of material orders, reorder points, and maximum inventory amounts to obtain the total inventory cost and service level. The simulation results on three selected materials, namely Prepaid kWh Meter, Postpaid kWh Meter, and MCB 4A, show that there is a significant decrease in total costs and an increase in service levels. The highest decrease in total costs and improvement in service levels are found in MCB 4A material, with a 77% decrease in total costs of 77% and 100% rise in service levels compared to the existing conditions. The proposed material inventory policy using the Min Max method and Monte Carlo Simulation for the current existing conditions of ULP provides benefits in terms of lower total inventory costs, lower stockout costs, and higher service levels