Multistage centrifugal pumps are the critical equipment in the water injection system in oil and gas processing facilities but often fail due to abrasive and corrosive fluids. This research utilized the Computational Fluid Dynamics (CFD) approach to analyze the effect of sand particle size, produced water characteristics, and cavitation on the performance of three-stages API 610 BB3 water injection pumps. CFD simulations were performed by varying the sand particle size (10 μm, 100 μm, 100 μm) and produced water characteristics from three locations. The standard k-ε turbulence model and the Eulerian granular flow approach were utilized to model the multiphase flow. The results showed a decrease in pump efficiency of up to 10.39% dan head of up to 19.08% in 1000 μm particles. Analysis of the corrosion rate based on water characteristics showed the highest value of 0.198 mm/year at the location with the highest chloride content and conductivity. Cavitation zones were identified around the leading edge of the impeller at each stage. This study provides an in-depth understanding of the failure mechanisms of the water injection pumps. It can form the basis for developing effective mitigation strategies, such as design improvement, material selection and overhaul program.

This study aims to explore the characteristics of sago starch (Metroxylon sp.) after exposure to ultraviolet (UV) light, using a local sago variety known as Tawaro. Sago starch underwent Heat Moisture Treatment (HMT) to achieve 0% water content. Furthermore, this sago starch was used as a raw material for bioplastic production. The results of preliminary tests showed a tensile strength of 0.227 N/mm² (D0). Biodegradability testing was carried out on bioplastics exposed to UV light for 24 hours (D1UV24), 48 hours (D2UV48), and 72 hours (D3UV72). Fourier Transform Infra-Red (FTIR) analysis was used to identify the absorption patterns resulting from UV exposure. The results showed consistent absorption patterns before and after UV treatment, with no changes in functional groups or the emergence of new functional groups. However, changes detected in the intensity of the OH band broadening indicate photodegradation or oxidation. This is due to the formation of hydrogen bonds between the –OH groups of starch and glycerol. In addition, photodegradation affects mechanical properties, especially tensile strength. D1UV24 (0.406 N/mm²) and D2UV48 (0.619 N/mm²) showed an increase in tensile strength, while D3UV72 (0.538 N/mm²) decreased. This decrease was caused by prolonged oxidation, activating the polymer chain with free radicals. Contact angle testing showed that after the photodegradation process, the bioplastic became hydrophilic. These characterization data provide insight that Tawaro sago starch with 0% water content has the potential to be applied and developed as an environmentally friendly packaging product.

Soft Magnetic Composite (SMC) is a composite material made by binding iron (Fe) powder with non-magnetic materials such as epoxy resin. The main properties of SMC, which have high electrical resistance yet can efficiently conduct magnetic fields, make it a primary choice for various applications that require efficiency, reliability, and high performance. Extensive research has been conducted on SMC, making it necessary to perform a bibliometric analysis to categorize and observe developments in SMC research. The main objectives of this study are to understand patterns in scientific publications, identify the most productive research developments, determine research linkages, and identify collaboration networks related to SMC. A total of 1067 documents, 347 sources, and 2113 authors were recorded in the Scopus database between 2005 and 2024. The number of article publications has increased annually by 4.36%. China is the most productive country and also has the most extensive international collaboration networks. The majority of publications are published in journals with specific topics, primarily focusing on magnetics and magnetic materials.

The formation process of Fe3O4/EFB fiber was carried out by synthesizing FeCl3.6H2O and pineapple leaf extract using the green synthesis method. Pineapple leaf extract contains hydroxyl, carbonyl, and amine functional groups that can act as reductants and capping agents for the synthesized metal salts. Then, the in-situ impregnation was carried out to attach magnetite to the EFB fibers. The EFB fibers were then soaked in a mixture of precursor solution and pineapple leaf extract with a variation of liquor-to-good ratios of 1:40, 1:60, and 1:80 to determine the optimal ratio in forming Fe3O4/EFB fiber. In XRD testing, the three variations of samples have peak characteristics of magnetite (Fe3O4). SEM-EDX results also showed the Fe content from three samples tested. In the UV-Vis examination, the 1:80 sample has the highest percent degradation with 68.09%, and the lowest percent degradation belongs to untreated EFB with 12.44%. Visual tests showed that the 1:40, 1:60, and 1:80 variations could degrade methylene blue after 12 hours with addition of H2O2. H2O2 increases the reactivity of Fe3O4 by providing hydroxyl radicals that can attack pollutants and mineralize methylene blue into CO2 and H2O.

This study examines the hardness and tensile strength characterization of SS304 stainless steel welded using different electrode variations in the Shielded Metal Arc Welding (SMAW) process. The research focuses on three types of electrodes: NSN 308, NSN 309L, and NSN 312, to evaluate their influence on the mechanical properties of the weld metal. Hardness testing was conducted using the Vickers method with a 200-gf load, while tensile strength testing was performed to assess ultimate tensile strength (σu), yield strength (σy), and elongation (ε). The results indicate that the selection of electrodes significantly affects the hardness and tensile properties of the welded joints. NSN 312 exhibited the highest hardness values, particularly in the weld metal and filler areas, suggesting the formation of hard phases such as martensite or chromium-rich ferrite, making it suitable for wear-resistant applications. NSN 309L demonstrated moderate hardness, indicating a more balanced microstructure that provides good toughness and ductility. NSN 308 showed the lowest hardness values, which can be beneficial for applications requiring greater deformability. In the tensile test, NSN 309L achieved the highest ultimate tensile strength 47.77 Kg/mm² and elongation 45%, suggesting an optimal balance of strength and ductility. NSN 312 exhibited the highest yield strength 46 Kg/mm², indicating better resistance to plastic deformation. Meanwhile, NSN 308 had lower tensile properties compared to the other electrodes. Overall, electrode selection should align with specific application requirements. NSN 312 is recommended for wear-resistant applications, NSN 309L for structures requiring both strength and ductility, and NSN 308 for applications with lower mechanical stress.

Automatic Stacking Cranes are indispensable tools in modern ports that can transfer containers between the landside and the waterside. These cranes are powered by electricity and consume significant amounts of energy to meet annual production demands. This substantial electricity consumption often strains the port's power grid during voltage and current fluctuations, which can destabilize the ASC's power supply. Wind turbines offer a promising alternative energy source to address these problems. This study delves into the analysis of the optimal Axial Flux Generator structure for wind turbines and calculates the associated energy losses to determine the feasibility of a wind turbine system capable of supporting the ASC's power demands. The findings reveal that employing an AFG-based wind turbine can generate the required 88,497 Watts of power for the ASC, with an average rotational speed of 1,655 rpm. This represents an annual electricity cost saving for the port of approximately 39,701,029 Rupiah.

Over the years, technologies of 3D printing have enhanced the opportunity to ease the production of complex geometries. In particular, it further implies that the flexibility of materials is of a great importance. Therefore, the works covering studies of applicability on novel materials in rapid prototyping contribute to the development of additive manufacturing. The present work experimentally investigates a mechanical property, namely tensile strength, of 3D printing materials on the basis of the concentration of flexible-standard resins. Tensile strengths were obtained by a series of tensile tests. Here, the result reveals that the tensile strength monotonously decreases as the increase of the concentration of flexible resin’s concentration. Moreover, an ANOVA analysis strongly implies a consistent relationship between the tensile strength and the material’s mixture.

Penelitian tentang biomekanika gerak berjalan manusia memiliki posisi yang sangat penting di berbagai bidang. salah satunya adalah rehabilitasi, atletik, dan pembuatan kaki prostetik. Fokus dari penelitian ini untuk menganalisis tentang pengaruh variasi kecepatan pada treadmill terhadap parameter kinematika berjalan manusia seperti frekuensi, durasi langkah serta kecepatan dan percepatan sudut. Variasi kecepatan treadmill yang digunakan adalah 2,0; 2,5; dan 3,0 km/jam. Penelitian ini menggunakan desain studi kasus eksploratif (Single-subject case study) untuk mengevaluasi kelayakan dari sistem motion capture dengan menggunakan software Blender dan kamera GoPro Hero 9. Selanjutnya data akan dianalisa menggunakan MATLAB untuk mengetahui frekuensi, durasi langkah, serta kecepatan dan percepatan sudut setiap segmen sendi pada tubuh bagian bawah. Hasil menunjukkan bahwa peningkatan kecepatan treadmill menyebabkan durasi siklus berjalan yang lebih pendek, peningkatan frekuensi langkah, serta peningkatan kecepatan dan percepatan sudut segmen tubuh. Temuan ini memberikan wawasan tentang mekanisme adaptasi pola gerakan berjalan manusia dan kaitannya dalam rehabilitasi serta pelatihan atletik. Studi lebih lanjut sebaiknya mencakup jumlah partisipan yang lebih banyak dan mempertimbangkan faktor tambahan berupa gaya reaksi tanah untuk analisis yang lebih menyeluruh.

Serat rami dipilih karena memiliki sifat mekanik yang baik dan ramah lingkungan, sementara UHMWPE memiliki ketahanan yang tinggi terhadap abrasi dan benturan, serta sifat biokompatibilitas yang baik. Penggunaan kedua material ini diharapkan mampu menghasilkan komposit yang kuat, ringan, dan murah sebagai alternatif implan tulang. Penelitian ini untuk menganalisis pengaruh variasi panjang serat rami yang diperkuat dengan matriks UHMWPE terhadap sifat mekanik dan fisik komposit sebagai potensi biomaterial untuk aplikasi bone implan. Material yang digunakan yaitu serat rami dan serbuk UHMWPE. Menggunakan metode eksperimen dengan perlakuan serat rami yang direndam dengan cairan natrium hidroksida 5% dengan waktu perndaman selama 1 jam dengam panjang serat rami 3 mm, 5 mm, dan 7 mm dan perbandingan komposisi yang digunkan serat rami 5% dan UHMWPE 95%. Komposit dibuat menggunakan proses hot press pada suhu 215°C dan tekanan 370 kgf. Pengujian yang dilakukan meliputi uji tarik dan foto makro. Hasil penelitian menunjukkan bahwa variasi panjang serat memberikan pengaruh signifikan terhadap kekuatan tarik. Panjang serat 7 mm menyatakan nilai tegangan tarik tertinggi sebesar 17,53 Mpa, regangan tarik tertinggi sebesar 0,411, dan Modulus elastisitas tertinggi diperoleh pada variasi panjang serat 3 mm sebesar 61,86 MPa. Dari pengamatan foto makro tersebut dapat diketahui kegagalan yang terjadi pada patahan uji tarik yaitu adanya serat yang terlepas (fiber pull out), terdapat retakan kecil yang di sebabkan tegangan rendah saat diuji tarik (microcracking), terdapat rongga yang di sebabkan adhesi antara serat dan matriks tidak cukup kuat sehingga komponen tersebut terpisah (debonding).

Pemulihan patah tulang menggunakan fiksasi internal pelat yang berfungsi mempertahankan pengurangan retak selama penyembuhan tulang. Fiksasi internal pelat direkomendasikan bersifat biodegradasi secara biologis yang terbuat dari biokomposit polylactide/poly ɛ-caprolactone/nano hidroksiapatit (PLA/PCL/nHA). Material ini memiliki kekuatan mekanik tinggi, namun susah mengontrol waktu laju degradasi. Tujuan penelitian ini menciptakan fiksasi internal pelat dari biokomposit PLA/PCL/nHA dengan laju degradasi dapat diprediksi. Metode pembuatan spesimen dengan Cold Isostatic Pressing (CIP) dengan variasi penambahan prosentase komposisi nHA. Tekanan kompaksi 40 MPa, temperatur sintering 150oC dan waktu penahanan 3 jam. Bertambahnya komposisi nHA mempercepat laju degradasi dan hilangnya berat spesimen. Penambahan komposisi nHA semakin besar untuk erosi permukaan semakin tinggi. Hasil ini untuk rencana implementasi spesimen pada tingkatan umur pasien. Spesimen penambahan 10 wt% nHA untuk pasien diatas umur 50 tahun atau lansia. Spesimen penambahan 20 wt% nHA untuk pasien dewasa, sedangkan spesimen penambahan 30 wt% nHA untuk pasien bayi dan anak-anak.