Jurnal Politeknik Negeri Jakarta (PNJ)
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CONCRETE QUALITY IN SEAWATER USING GGBFS AS A CEMENT SUBSTITUTE
Get PDFIndonesia, as a maritime country, has many structures located in coastal and marine areas, which require the use of concrete with high resistance to aggressive environments. Seawater contains chloride and sulfate ions that can damage concrete structures, reduce strength, and accelerate the weathering process. On the other hand, the cement industry contributes significantly to global carbon emissions. One solution to enhance concrete durability while reducing carbon emissions is to use Ground Granulated Blast Furnace Slag (GGBFS) as a partial substitute for Portland cement. This study aims to analyze the quality of fresh concrete, including slump value, fresh concrete density, and initial setting time, as well as hardened concrete, including compressive strength, tensile strength, elastic modulus, and tensile stress, with concrete curing using seawater as the curing medium. The study was conducted by preparing concrete cylinder specimens with a water-cement ratio of 0.38. The specimens were prepared with four variations: 0%, 20%, 40%, and 60% of the cement weight. The study used Jalupang sand and Superplasticizer Nexplast N 6035 Admixture type F by PT. Nexco Indonesia. The results showed that the addition of GGBFS reduced the workability of fresh concrete but significantly increased compressive strength and elastic modulus at certain levels. The optimal composition was found at 40% GGBFS, which produced the best mechanical performance of concrete according to SNI standards. These findings indicate that GGBFS can be an effective environmentally friendly alternative material for improving concrete performance in seawater environments
Analisis Pengaruh Perubahan Beban Terhadap Nilai Turbin Heat Rate dan Efisiensi Termal Turbin pada PLTU Cilacap
Get PDFFluctuations in operating load at the Cilacap Steam Power Plant (PLTU) often cause changes in steam turbine performance that affect generation efficiency and fuel consumption. This study aims to assess the effect of load variations on turbine heat rate, measure changes in thermal efficiency, and analyse their impact on fuel consumption and generation costs. A quantitative correlational method was applied using secondary data from the December 2023 periode, including electrical load parameters, steam flow rate, inlet-outlet enthalpy, and generator output. Heat rate and thermal efficiency calculations were performed based on thermodynamic formulas, while fuel consumption and cost analysis were conducted through comparisons of values per kWh. The results show that an increase in operating load consistently reduces the heat rate and improves thermal efficiency, meaning that steam energy is utilised more optimally. Additionally, fuel consumption and generation costs tend to decrease as the load approaches optimal conditions. These findings underscore the importance of maintaining the operating load within an appropriate range to maximise energy efficiency, reduce fuel consumption, and minimise electricity production costs at the Cilacap Coal-Fired Power PlantFluktuasi beban operasi pada Pembangkit Listrik Tenaga Uap (PLTU) Cilacap sering menimbulkan perubahan kinerja turbin uap yang berpengaruh pada efisiensi pembangkitan dan konsumsi bahan bakar. Penelitian ini bertujuan untuk menilai pengaruh variasi beban terhadap heat rate turbin, mengukur perubahan efisiensi termal, serta menganalisis dampaknya pada konsumsi bahan bakar dan biaya bahan bakar. Metode kuantitatif korelasional diterapkan dengan menggunakan data sekunder dari periode Desember 2023, meliputi parameter beban listrik, laju alir uap, entalpi inlet outlet, dan output generator. Perhitungan heat rate dan efisiensi termal dilakukan berdasarkan rumus termodinamika, sedangkan analisis konsumsi bahan bakar dan biaya dilakukan melalui perbandingan nilai per kWh. Hasil menunjukkan bahwa peningkatan beban operasi secara konsisten menurunkan nilai heat rate dan meningkatkan efisiensi termal yang berarti energi uap dimanfaatkan lebih optimal. Selain itu konsumsi bahan bakar dan biaya bahan bakar cenderung menurun ketika beban mendekati kondisi optimal. Temuan ini menegaskan pentingnya menjaga beban operasi pada rentang yang tepat untuk memaksimalkan efisiensi energi, mengurangi konsumsi bahan bakar, dan menekan biaya bahan bakar di PLTU Cilaca
Optimasi Desain Jig Untuk Check Hole Pada Komponen Dudukan Shockbreaker Mobil
Get PDFPerusahaan manufaktur sangat membutuhkan perangkat untuk pengecekkan hasil produksi, perangkat tersebut dinamakan dengan JIG, JIG sendiri merupakan sebuah tatakan. Apabila barang produksi akan disambung maka dibutuhkan JIG untuk metata hasil produksi, namun pada penelitian ini JIG dibutuhkan untuk proses pengecekkan hole hasil produksi dudukan shockbreaker. Tujuan dari penelitian ini adalah melakukan optimasi desain JIG agar dilakukan pengecekkan suaian lubang duduk shockbreaker dan datum pada JIG. Urgensi penelitian ini adalah pentingnya optimasi agar produk dapat dilakukan pengecekkan yang sesuai dengan JIG yang akan digunakan sebagai alat pengecekkan. Metode penelitian yaitu melakukan pengukuran dudukan shockbreaker pada 4 bagian lubang menggunakan mistar mm dan jangka sorong digital, setelahnya dilakukan proses desain CAD. Selanjutnya pemilihan material, material yang digunakan adalah S45C. Proses manufaktur menggunakan CNC. Hasil penelitian menunjukkan pada lubang 1 tidak ada toleransi, pada lubang 2 P = +0,02 mm dan L = +0,03 mm, pada lubang 3, D = -2 mm dan pada lubang 4 P = +0,025 mm L = -0,03 mm. Penentuan toleransi tersebut agar datum untuk check hole pada dudukan suaian pas. Penelitian ini mengacu pada penelitian Abdullah et.al yang berjudul Computer-Aided Design of Traditional Jigs and Fixtures yaitu pentingnya nilai toleransi untuk medapatkan suaian hasil pembuatan JIG.Jig atau tatakan merupakan sebuah dudukan yang digunakan untuk membatu proses manufaktur dari sebuah proses, dengan adanya jig maka semua komponen dapat dipasangkan unntuk membantu suatu kerjaan proses produksi, saat ini penggunaan jig sangat membantu bagi perusahaan produksi, latar belakang dari penelitian ini membahas optimasi desain dan pembuatan jig dalam proses pengecekkan lubang pada sparepart dudukan shockbreaker dari salah satu mobil, permasalahan yang timbul adalah dalam proses pengecekkan lubang pada dudukan shockbreaker mobil memakan waktu yang lama karena terdapat 4 lubang dalam satu komponen. Oleh karena itu tujuan dari penelitian ini adalah merancan jig check hole untuk komponen dudukan shockbreaker dari sebuah mobil agar dapat mempersingkat waktu dalam proses pengecekkan hasil proses produksi dudukan shockbreaker mobil. Metode yang digunakan yaitu pengukuran, perancangan, pembuatan dan pengujian. Hasil penelitian menunjukkan ke empat titik kritis pengukuran maka pada titik 1toleransi hanya ditetapkan D = 0 mm, titik ke 2 toleransi yang diterapkan sebesar P = +0,02 mm L = +0,03 mm, titik ke 3 sebesar D = -2 mm dan titik ke 4 menunjukkan nilai toleransi sebesar P = +0,025 mm L = -0,03 mm. Toleransi tersebut diterapkan agar datum yang dirancang dapat masuk ke lubang dudukan shockbreaker pada saat proses QC
Perencanaan Layout 3D untuk Sistem Pengolahan Air Limbah di Kapal Penumpang
Get PDFAs an archipelagic nation, Indonesia relies heavily on passenger ships to maintain inter-island connectivity. However, the operation of these vessels generates domestic wastewater that may cause marine pollution if not properly managed. A vacuum based piping system offers an efficient technical solution especially suitable for limited onboard space. This study aims to design a 3D layout of a vacuum assisted sanitary wastewater collection system and to calculate the required vacuumarator capacity to transfer waste from toilets and sinks to a holding tank for further treatment by STP. The research applied an engineering design approach consisting of five stages: regulatory review, technical data collection, vacuum capacity calculation, component specification comparison, and 3D modeling. Results show that the required vacuum capacity ranges from 490 to 840 flushes per hour, depending on whether ISO or vendor calculation. The Jets 15MB-D was selected due to its compatibility with the minimum STP capacity, energy efficiency, lightweight and compact, and suitability with DN40 pipe connections. The 3D layout places the vacuumarator near the STP to minimize pressure loss and simplify maintenance. The proposed design complies with MARPOL Annex IV and BKI rules and can serve as a reference for retrofitting sanitary systems on domestic passenger ships.Indonesia sebagai negara kepulauan sangat bergantung pada kapal penumpang untuk konektivitas antarpulau. Operasional kapal ini menghasilkan limbah domestik yang berpotensi mencemari laut jika tidak dikelola dengan baik. Sistem perpipaan berbasis vakum menjadi solusi teknis yang efisien dan sesuai untuk ruang sempit di kapal. Penelitian ini bertujuan merancang layout secara 3D sistem pengumpulan dan pengolahan limbah sanitasi berbasis vakum serta menghitung kapasitas vacuumarator yang dibutuhkan agar limbah dari toilet dan wastafel dapat dialirkan ke holding tank dan diproses oleh STP. Metode yang digunakan adalah rekayasa desain dengan lima tahap: kajian regulasi, pengumpulan data teknis, perhitungan kapasitas vakum, komparasi spesifikasi komponen, dan pemodelan 3D. Hasil menunjukkan bahwa kebutuhan kapasitas vakum berkisar 490–840 flushes/jam tergantung perhitungan ISO atau vendor. Jets 15MB-D dipilih karena memenuhi kapasitas minimum STP, hemat energi, ringan, dan kompatibel dengan pipa DN40. Model layout 3D menunjukkan penempatan vacuumarator berdekatan dengan STP untuk meminimalkan rugi tekanan dan memudahkan perawatan. Desain yang dihasilkan memenuhi ketentuan MARPOL Annex IV dan BKI, serta dapat menjadi acuan retrofit sistem sanitasi kapal penumpang domestik
Evaluasi Produktivitas Mesin Web Offset Berbasis Overall Equipment Effectiveness (OEE) dan Failure Mode and Effects Analysis (FMEA)
Get PDFPenelitian ini bertujuan untuk menganalisis tingkat produktivitas mesin Web Offset dengan menggunakan metode Overall Equipment Effectiveness (OEE) dan Failure Mode and Effects Analysis (FMEA). Mesin Web Offset merupakan salah satu mesin produksi utama dalam industri percetakan yang dituntut memiliki tingkat efektivitas tinggi untuk memenuhi kebutuhan produksi. Hasil perhitungan OEE menunjukkan bahwa nilai efektivitas mesin masih berada di bawah standar ideal 85%, yang disebabkan oleh rendahnya nilai performance serta tingginya tingkat kerusakan (breakdown). Analisis FMEA dilakukan untuk mengidentifikasi potensi kegagalan pada komponen mesin dan menilai tingkat risiko melalui perhitungan Risk Priority Number (RPN). Hasil analisis menunjukkan bahwa komponen seperti sistem feeder, unit tintaan, dan sistem penarikan kertas memiliki nilai RPN tertinggi sehingga perlu mendapat prioritas perbaikan. Kombinasi metode OEE dan FMEA memberikan gambaran menyeluruh mengenai sumber-sumber kerugian serta titik kritis pada mesin, sehingga dapat digunakan sebagai dasar strategi peningkatan produktivitas melalui tindakan korektif dan preventif yang lebih terarah.
Kata kunci: Overall Equipment Effectiveness, Failure Mode and Effects Analysis, Machine Productivity, Web Offset Printing, Risk Priority Numbe
Identifikasi Faktor Penyebab Penurunan Produktivitas Mesin Lithrone S40 Menggunakan OMAX–FTA
Get PDFABSTRAK
CV XYZ mengalami fluktuasi produktivitas pada proses cetak menggunakan mesin offset Lithrone S40. Penelitian ini bertujuan mengidentifikasi faktor penyebab penurunan produktivitas menggunakan metode Objective Matrix (OMAX) dan Fault Tree Analysis (FTA). Hasil pengukuran OMAX selama 19 periode menunjukkan produktivitas berfluktuasi, dengan indeks tertinggi sebesar 116,5% dan terendah –90,9%. Rasio dengan skor terendah adalah efisiensi produksi terhadap tenaga kerja, sehingga dianalisis lebih lanjut melalui FTA. Analisis FTA mengungkap enam akar penyebab utama, yaitu ketidaktelitian operator dalam pemasangan plat, mesin tidak dikalibrasi, daya hisap dan hembusan tidak optimal, pengaturan sistem penghisap kertas tidak tepat, tinta cepat mengering, serta kertas yang saling menempel. Usulan perbaikan meliputi pelatihan operator, kalibrasi rutin mesin, perbaikan sistem udara, pengaturan tekanan penghisap, pengendalian suhu–kelembapan, serta penanganan kertas yang lebih baik. Temuan ini diharapkan dapat membantu meningkatkan produktivitas proses cetak secara konsisten.
Kata kunci: OMAX, FTA, produktivitas, mesin offset, Lithrone S40
Analisis Interaksi Audiens terhadap Konten Berita Internasional di Instagram ANTARA News: Pendekatan Mixed Methods pada Strategi Engagement Digital
Get PDFThis study aims to analyze audience interaction patterns toward international news content published on the official Instagram account of ANTARA News. Unlike previous studies focusing on distribution strategies, this research emphasizes engagement analysis using a mixed-methods approach that combines quantitative data (likes, comments, hashtags) and qualitative data (caption and visual content analysis). The study employs a mixed-methods design, collecting quantitative data from posts uploaded in June 2025 and qualitative insights from five top-engagement posts. The results indicate that audience engagement levels positively correlate with the relevance of themes, visual clarity, and narrative depth in captions. These findings support Social Media Engagement Theory (van Doorn) and Media Convergence (Jenkins), highlighting the importance of interaction-based content management in shaping editorial direction and optimizing international news distribution strategies on digital platforms.Penelitian ini bertujuan untuk menganalisis pola interaksi audiens terhadap konten berita internasional yang dipublikasikan di akun Instagram resmi ANTARA News. Berbeda dengan studi sebelumnya yang berfokus pada strategi distribusi berita, penelitian ini menitikberatkan pada analisis engagement berbasis data kuantitatif (likes, komentar, tagar) dan kualitatif (analisis isi caption dan visual). Metode yang digunakan adalah mixed methods, dengan data kuantitatif diperoleh melalui observasi unggahan periode Juni 2025 dan data kualitatif melalui analisis konten mendalam terhadap lima unggahan dengan tingkat interaksi tertinggi. Hasil penelitian menunjukkan bahwa tingkat interaksi audiens berkorelasi positif dengan relevansi tema, kejelasan visual, dan kedalaman narasi pada caption. Temuan ini mendukung teori Social Media Engagement (van Doorn) dan Media Convergence (Jenkins), serta menegaskan pentingnya pemanfaatan data interaksi dalam menentukan arah editorial dan strategi distribusi berita internasional di platform digital
Beyond the 'Right Answer': A Synthesis of Process-Oriented and Authentic Assessment in English Language Education
Get PDFAssessment in English Language Teaching (ELT) is at a critical juncture, moving away from traditional, product-focused evaluation towards more holistic, learner-centered paradigms. This article synthesizes conceptual and empirical literature to argue for an integrated assessment framework grounded in sociocultural learning theory. Traditional assessment methods, often characterized by standardized tests and factual-recall questions, promote a narrow conception of learning, create negative washback effects, and can perpetuate systemic inequities. In response, this article examines an alternative paradigm rooted in Assessment for Learning (AfL), which emphasizes process-oriented, authentic, and performance-based approaches. A systematic review of the literature was conducted, focusing on key pillars of alternative assessment, including performance-based tasks, portfolio assessment, and the mediational roles of feedback, interaction, and scaffolding. The findings indicate that these alternative methods, when unified under a Vygotskian framework of the Zone of Proximal Development (ZPD), are more effective at fostering communicative competence, critical thinking, and learner autonomy. The discussion addresses the pedagogical implications of this framework across the four language skills, confronts the significant implementation challenges, including the need for enhanced teacher assessment literacy and the reality of standardized testing, and considers the ethical dimensions of assessment. The article concludes that a thoughtful integration of process and authentic assessment is not merely a pedagogical choice but a necessary step toward empowering students as confident, lifelong language learners
Pengaruh Kualitas Pelayanan Terhadap Kepuasan Nasabah pada PT Bank BTN Cabang Panakkukang Kota Makassar: Pengaruh Kualitas Pelayanan Terhadap Kepuasan Nasabah
No full textThis research aims to analyze the influence of service quality on customer satisfaction at PT Bank BTN Panakkukang Branch, Makassar City. Data was collected through questionnaires distributed to 120 respondents. Data analysis was carried out using the Statistical Package for the Social Sciences.SPSS version 29 software, with a simple linear regression method to identify the relationship between service quality variables and consumer satisfaction. The results of descriptive analysis show that the average service quality score is 4.12, and consumer satisfaction is 4.16. Simple regression analysis shows that these variables simultaneously have a significant effect on consumer satisfaction (F=215.328; p<0.05F= 215.328; p<0.05. Partially, the service quality variable has an influence coefficient of 0.809
Keywords: Service quality, customer satisfactionPenelitian ini bertujuan untuk menganalis pengaruh kualitas pelayanan terhadap kepuasan nasabah PT Bank BTN Cabang Panakkukang Kota Makassar. Data dikumpulkan melalui kuesioner yang disebarkan kepada 120 responden. Analisis data dilakukan menggunakan perangkat lunak Statistical Package for the Social Sciences.SPSS versi 29, dengan metode regresi linier sederhana untuk mengidentifikasi hubungan antara variabel kualitas pelayanan dan kepuasan nasabah. Hasil analisis deskriptif menunjukkan bahwa rata-rata skor kualitas pelayanan adalah 4.12, dan kepuasan nasabah 4.16. Analisis regresi sederhana menunjukkan bahwa variabel tersebut secara simultan berpengaruh signifikan terhadap kepuasan nasabah (F=215.328 ;p<0,05F= 215.328; p<0,05. Secara parsial, variabel kualitas pelayanan memiliki koefisien pengaruh sebesar 0,809
Kata kunci: Kualitas pelayanan, Kepuasan nasaba
EVALUATION OF THE IMPLEMENTATION OF PERMENDAGRI NO. 20 OF 2018 IN VILLAGE FINANCIAL MANAGEMENT: A CASE STUDY OF PEMUDA VILLAGE
Get PDFThis study aims to evaluate the financial management of Desa Pemuda based on Permendagri No. 20 of 2018 concerning village financial management. The regulation outlines five key stages: planning, implementation, administration, reporting, and accountability. Financial management in villages must be carried out in a transparent, accountable, participatory manner, and in accordance with budget discipline. This study was conducted to determine whether the financial management practices in Desa Pemuda align with the provisions of the regulation. This research uses a qualitative descriptive method. Data were collected through interviews with village officials, analysis of supporting documents, and field observations. The evaluation indicators were developed based on the regulatory framework and were used to assess compliance at each stage. The results show that the financial management of Desa Pemuda has generally complied with the applicable regulations. The planning, administration, and reporting stages are mostly in accordance with the rules, supported by relevant documents and procedures. However, there are still shortcomings at the implementation and accountability stages, such as the absence of several official documents like the 2024 DPA and the unavailability of a complete SK for task assignments to village officials. Additionally, public involvement and transparency in delivering information still need improvement. These findings suggest the importance of strengthening documentation management and increasing the capacity of village officials through training and technical assistance.This study aims to evaluate the financial management of Desa Pemuda based on Permendagri No. 20 of 2018 concerning village financial management. The regulation outlines five key stages: planning, implementation, administration, reporting, and accountability. Financial management in villages must be carried out in a transparent, accountable, participatory manner, and in accordance with budget discipline. This study was conducted to determine whether the financial management practices in Desa Pemuda align with the provisions of the regulation. This research uses a qualitative descriptive method. Data were collected through interviews with village officials, analysis of supporting documents, and field observations. The evaluation indicators were developed based on the regulatory framework and were used to assess compliance at each stage. The results show that the financial management of Desa Pemuda has generally complied with the applicable regulations. The planning, administration, and reporting stages are mostly in accordance with the rules, supported by relevant documents and procedures. However, there are still shortcomings at the implementation and accountability stages, such as the absence of several official documents like the 2024 DPA and the unavailability of a complete SK for task assignments to village officials. Additionally, public involvement and transparency in delivering information still need improvement. These findings suggest the importance of strengthening documentation management and increasing the capacity of village officials through training and technical assistanc