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Effects of The Addition of Carbon on Abaca Fiber and PVA Composite Materials Based on Mechanical and Acoustic Properties
Get PDFAbaca is a kind of banana that grows in Indonesia. Abaca banana product utilized in this research is a fiber that obtained from the midrib of the stem. Henceforth, abaca fiber is processed to be the form of membranes. The purpose of the study are to determine the physical, mechanical and acoustic properties of abaca fiber composite materials as fillers and polyvinyl acetate (PVA) as a matrix. The ratio of composite materials of abaca fibers and PVA is 1:10. The variations used in producing membranes are the addition of carbon powders by 0%, 2%, 4%, 6% and 8%. The characteristics carried out include testing of density, morphology, tensile strength and sound absorption coefficient. The results reveal that the highest density is obtained from the sample of 0% carbon, i.e., 1.026 gr/cm3. Furthermore, the mechanical properties testing shows the highest yield stress value in samples with 4% carbon of 476.8 MPa and the highest Young modulus in samples with 8% carbon is 7905.1 MPa. Therefore, the addition of carbon could improve the mechanical properties of composites materials. Based on the measurement of sound absorption coefficient using an impedance tube with 1 microphone, the highest value can be attained from the sample of 4% carbon, namely 0.211 which shows the sample is more reflective. The material is reflective because the amount of abaca fiber used is less than PVA. The diameter of pores formed between the fiber and PVA are very small which could cause the absorption coefficient value to be lower. Therefore, further research will focus on the addition of abaca fiber content in composite materials. The positive point in this study is that the addition of carbon with 4% and 8% provides optimal mechanical ability
Fatigue Life Analysis of FSO Anchor Chain with Corrosion Effect
Get PDFIn this study, the authors analyze the fatigue life of the anchor chain used to secure the Gamkonora FSO to the seabed. The objective is to determine the operational lifespan of the anchor chain by considering its fatigue life. The research begins with an analysis of the movement of the Gamkonora FSO under environmental loads in both free-floating and moored conditions to determine the tension in each anchor chain. Next, the anchor chain tension is calculated for various corrosion levels, namely 0%, 5%, 10% and 15%. Subsequently, the tension range and damage ratio values are determined using the T-N curve method based on Palmgren Miner’s failure law, with failure estimation carried out using the rainflow counting method. The numerical modeling results reveal that the largest translational motion behavior of the FSO occurs during heave motion, reaching 1.409 m/m, while the largest rotational motion is observed during roll motion, with a value of 3.463 deg/m when the FSO is fully loaded. The maximum tension recorded in the anchor chain is 1,695.14 kN at heading 90 under 0% corrosion conditions, with a safety factor of 4.53. Furthermore, the cumulative damage value from the T-N curve is obtained, with the largest value recorded as 0.0702. Based on the cumulative damage, the fatigue life of the anchor chain is estimated to be 14.25 years during its operational lifespan
Leading Edge Modification of NACA 0015 and NACA 4415 Inspired by Beluga Whale
Get PDFThis research modifies the leading-edge structure of NACA 0015 and NACA 4415 to resemble the nose of a beluga whale. The focus of this modification is to improve the airfoil's aerodynamic performance and investigate the changing fluid flow patterns. Numerical equation used is RANS combined with the k-ε turbulence model. Mesh independence test shows that mesh with 200 elements is the best mesh. Validation results reveal that CFD data can follow the trend of experimental data, especially on the AoA before the stall. There was a significant increase in Cl from NACA 0015 and NACA 4415 at AoA>9°. On the other hand, the modification also had a positive effect by lowering the Cd value. The modification also provides an advantage by increasing the maximum Cl/Cd value. Furthermore, the separation point data shows that the modification can delay the separation of the fluid flow in the airfoil. Modifications can cause an increase in pressure on the lower side and a decrease in pressure on the upper side. Through velocity contours and streamlines, the modifications can reduce the recirculation area. Overall, modifying the leading edge has positive impacts on the NACA 0015 and NACA 4415 airfoils
Bilangan Kromatik Lokasi Pada Graf Amalgamasi Kipas Berekor
Get PDFMisalkan = (, ) graf terhubung dan suatu -pewarnaan dari . Misalkan = {1, 2, . . . , } merupakan partisi terurut dari () ke dalam kelas warna yang dihasilkan. Berdasarkan pewarnaan titik, maka representasi titik terhadap disebut kode warna dari , dinotasikan dengan (). Kode warna () dari suatu titik ∈ () didefinisikan sebagai k-pasang terurut, yait
Analisa Uses & Activities pada Placemaking Gedung Filateli Jakarta
Get PDFBangunan cagar budaya memuat identitas budaya dan merupakan saksi perkembangan peradaban. Namun pada tatanan kehidupan modern bangunan cagar budaya tidak lagi memiliki fungsi yang sama dengan mulanya. Adanya perbedaan fungsi tersebut merupakan salah satu upaya untuk mempertahankan keberadaan bangunan tersebut melalui melahirkan fungsi baru yang menyesuaikan dengan kebutuhan kehidupan sosial budaya saat ini. Siasat tersebut juga merupakan salah satu upaya melaksanakan pembangunan minim emisi dengan cara mengoptimalkan fungsi dari bangunan yang sudah ada. Prinsip yang erat kaitannya dengan praktik optimasilasi bangunan cagar budaya dikenal dengan adaptive reuse. Pada objek bangunan cagar budaya strategi adaptive reuse dijalankan dengan pendekatan placemaking. Gedung Filateli merupakan bangunan cagar budaya yang direvitalisasi dengan pendekatan placemaking. Artikel ini bertujuan untuk mengidentifikasi indikator uses dan activities pada placemaking fase I Gedung Filateli, khususnya area great hall. Identifikasi indikator uses dan activitiy bertujuan untuk mengetahui terpenuhi atau tidaknya kebutuhan masyarakat melalui pendekatan placemaking yang dilakukan pada Gedung Filateli. Metoda yang digunakan dalam penulisan artikel ini adalah observasi dan deskriptif. Berdasarkan penelitian yang telah dilakukan pada placemaking Gedung Filateli khususnya area great hall , area tersebut berhasil mewadahi beragam aktivitas dan program kegiatan sehingga indikator uses dan activities sudah teridentifikasi dan terpenuhi.
Reliability and Risk Analysis of Lubrication System on Sabuk Nusantara 43
Get PDFThis study aims to present a systematic approach to evaluating the reliability of the lubrication system on the Sabuk Nusantara 43. The methods used in conducting risk assessments are quantitative methods and qualitative methods or semi-quantitative methods. In the quantitative method, the approach taken is more to the value (number) approach. Meanwhile, in the semi-quantitative method, the approach used is a qualitative approach and a quantitative approach. This method can identify potential events that not only cause disruption to pipeline operations but also events related to safety and the environment. The results showed that the biggest risk in the installation of Sabuk Nusantara 43 lubricant was found in the filter section with damage levels reaching five times in one year with risk matrix plotting in the major category (Not Acceptable) and risk control options (recommendation). Selection of filter components that are better and fulfill standards of existing rules, regular maintenance and checking, and avoiding the use of lubricating oil that is too old and used
