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Potential of Cellulose Acetat Separator of Empty Palm Oil Fruit Bunches and Polyvinylidene Fluoride for Energy Storage Applications
Full text linkOne of the components that play an important role in maintaining battery security is the separator. The separator plays a role in preventing short circuits due to direct exchange between the anode and cathode in the battery cell. To avoid leakage or short circuit during the process, the separator must have good mechanical properties. For this reason, modifications are needed to improve the characteristics of the separator. The modification process was carried out by mixing Poyvinylidene Fluoride (PVDF) and cellulose acetate (CA) polymers. The CA used in this study was obtained by utilizing natural waste extracts in the form of empty oil palm fruit bunches (EFB). This study aims to see the effect of variations in the addition of CA EFB and PVDF on the characteristics of the resulting separator. Synthesized CA EFB was characterized using Fourier Transfor Infrared (FTIR) spectroscopy which showed that cellulose had been successfully synthesized into cellulose acetate.. The separator produced in this study showed good electrolyte absorption, indicated by the occurrence of an oxidation-reduction reaction process on the hysteresis curve with a wider and reversible loop upon the addition of 0.2 g CA. The mechanical characteristics of the separator also increased with the addition of CA concentration, the separator with the addition of 0.3 g CA showed the highest tensile strength value of 62.335 MPa and the highest porosity value of 89.35%. The separator with the addition of 0.3 g of cellulose acetate also decomposes more quickly, indicated by a weight loss percentage of 60%. The results of this test indicate that the addition of CA EFB and PVDF can affect the physical and mechanical characteristics of the separator which has the potential to become a battery separator
Degradasi Rhodamin B oleh Bi4Ti3O12 yang Diperoleh dari Metode Lelehan Garam Campuran NaCl/KCl
Full text linkRhodamin B adalah salah satu limbah zat warna yang berbahaya bagi ekosistem sehingga diperlukan usaha-usaha untuk menanganinya. Salah satu metode yang berpotensi digunakan dalam menangani limbah rhodamin B adalah metode fotokatalis. Salah satu senyawa yang mempunyai kemampuan aktivitas fotokatalis yang baik adalah senyawa Bi4Ti3O12 dengan partikel bermorfologi plate-like/sheets. Salah satu metode sintesis yang dapat menghasilkan Bi4Ti3O12 bermorfologi plate-like/sheets adalah metode lelehan garam. Dalam penelitian ini telah disintesis Bi4Ti3O12 dengan metode lelehan garam campuran KCl/NaCl dan selanjutnya dilakukan uji degradasi rhodamin B. Difraktogram senyawa produk menunjukkan bahwa senyawa target Bi4Ti3O12 telah berhasi disintesis akan tetapi masih ditemukan sedikit pengotor berupa TiO2 (rutil). Mikrograf menunjukkan bahwa senyawa produk mempunyai morfologi plate-like/sheets, dengan ukuran partikel pada rentang 2-6 μm. Hasil perhitungan spektrum reflektan dengan menggunakan persamaan Kubelka-Munk menunjukkan bahwa energi celah pita Bi4Ti3O12 adalah 2,88 eV. Hasil uji kemampuan degradasi menunjukkan bahwa rhodamin B mengalami penurunan konsentrasi pada rentang 39,84% sampai 50,61% dalam waktu 60 menit
Performance Analysis of Multiple Input Multiple Output (MIMO) Multi-Carrier Code-Division Multiple Access (MC-CDMA) Combined with Quasi-Orthogonal Space Time Block Coding (QO-STBC) in Rayleigh Fading Channel
Full text linkThe need for a communication system with a higher data rate and mobility grows along with information and communication technology development. Combining MC-CDMA with the MIMO system and supporting the system with a good transmit diversity technique is a promising idea to provide the needed communication system, especially in high mobility conditions. MC-CDMA can support ubiquitous communications without affecting the achievable BER and is more capable of high-speed mobility. It integrates the benefit of both OFDM and CDMA. On the other hand, QO-STBC increases the bit rate without using additional bandwidth to transmit diversity in the MIMO system. So, this study proposed a system combining the MIMO MC-CDMA system with QO-STBC. The proposed system is investigated under high mobility conditions to see the system's performance. The simulation results show that our system performs better than the MC-CDMA STBC system and the QOSTBC system but not better than the MC-CDMA multilevel coding scheme. To reach the value of BER 10−3, MC-CDMA multilevel Coding requires less power, around 5 dB, than the proposed system
The Effect of Cell Surface Area on the Effectivity and Reusability of Bixin Sensitized Solar Cells
Full text linkDye-Sensitized Solar Cells or DSSC is the latest solar cell type generation that uses natural dyes as sensitizers. Bixin extracted from the seeds of kesumba (Bixa orellana L) is one of the natural dyes that can be used as a sensitizer. This study aims to determine the effect of the active surface area of solar cells on the effectivity and reusability of bixin-sensitized solar cells based on their open-circuit voltage (Voc), short-circuit current (Isc), and maximum energy conversion efficiency. The results of this study will provide an overview of the best surface area to produce DSSC with the highest maximum energy conversion efficiency and the lifetime of bixin sensitized solar cells. The measurement results showed that the resulting Voc for each variation of the surface area 1, 2, and 3 cm2 was 344; 719; 1002 mV under intensity 100 mW cm-2, while the Isc produced under the same intensity was 0.223; 0.471; 0.680 mA. Based on the calculation results, the maximum power generated by each surface area was 0,077; 0,338; 0,681 W. This means that the larger the active surface area of the solar cell, the greater the voltage and current generated. In this work, the highest efficiency was produced by solar cells with a surface area of 2 cm2, which is 0.085%. The solar cells fabricated in this study can be reused for five days under continuous irradiation
Water Hyacinth Utilization: A New Perspective on the Smoke-salted Duck Egg Process in Three Different Blended Fuels
Full text linkSmoke-salted duck eggs (SDEs) one of Indonesia's most well-known egg food preservation methods. It not only increases the shelf life of smoked-salted duck eggs, but it also imparts a distinguishable flavor and taste to them. The SDEs process requires a boiling/steaming process that requires fuel for about 30% of the total energy required. The water content in water hyacinth is around 90%, which provides an opportunity to be used as a fuel that eliminates the boiling/steaming process. The water hyacinth (Eichhornia Crassipes) has never been used to produce SDEs as an alternative energy source. The dry bulb's temperature was kept below 95 o C. The relative humidity was managed to keep above 40% for the first two hours and 30% for the next six hours for the three different blended fuels (TDBF) methods for smokesalted duck eggs. The TDBF smoking method has significantly benefited from water hyacinth in the smoked salted duck egg process. The high water content of water hyacinth is advantageous so that the boiling/steaming process is successfully eliminated. The smoke-salted duck eggs processed using the TDBF smoked method had an egg maturity of more than 60% after 1.5 - 2 hours and around 100% after 3 -6 hour
Seismic Site Classification Using the Multichannel Analysis of Surface Waves Method
Full text linkThe soil has a variety of qualities that affect its ability to support the weight of a structure. One of these features is soil stiffness, which can be determined using the surface wave method to prevent soil collapse. Multichannel Analysis of Surface Waves (MASW) is one of the non-invasive methodologies used in this study to investigate subsurface structures in North Sumatra, Indonesia. This method utilizes the dispersion properties of Rayleigh waves, producing a dispersion curve to get the shear wave velocity (Vs) through inversion. The shear wave velocity can be used to examine the soil stiffness qualities. The dispersion curve explains the relationship between shear wave velocity and depth, which can subsequently be used as a site class parameter. This survey uses three lines with one shot for each line which uses thirty geophones. The seismic source used is a gun with the type M16.38 Cal. Each line consists of 30 geophones with a distance of 5 m. The entire track is 160 m long and lasts for 2048 seconds with a sampling rate of 0.00025 seconds. The average shear wave velocity measured at three measurements was 372.5 m/s on line P1, 347.1 m/s on line P2A, and 311.0 m/s on line P2B, respectively. Overall, the soil classification on the P1 line is class C, and the P2A and P2B lines are class D, which is suitable for development planning areas
Optimalisasi Data Gayaberat untuk Pemodelan Struktur Geologi Bawah Permukaan Daerah Kepulauan Sabu-Raijua, Nusa Tenggara Timur, Indonesia
Full text linkKawasan Timur Indonesia (KTI) yang merupakan daerah frontier meliputi sepertiga luas cekungan sedimen di Indonesia. Namun sampai dengan saat ini hanya beberapa cekungan sedimen yang berproduksi. Kendala yang dihadapi di daerah frontier adalah ketersediaan dan kualitas data yang kurang memadai. Data gayaberat dapat dijadikan solusi alternatif dalam memberikan gambaran awal kondisi bawah permukaan di daerah frontier. Analisis lanjut dilakukan dengan mengkompilasi land gravity data (onshore) dengan topex free air gravity data yang dikoreksi menjadi anomali bouguer untuk mengungkap daerah offshore, penerapan metode Second Vertical Derivative (SVD) untuk mendelineasi struktur geologi dan metode Euler 3D Deconvolution dalam memperkirakan kedalaman sumber anomali gayaberat yang umumnya dilakukan dengan analisis spektral. Hasil penelitian menunjukkan adanya anomali gayaberat tinggi yang diinterpretasikan sebagai prismatic body di bawah Pulau Sabu – Raijua. Prismatic body diduga terbentuk karena terdapat dua arah tegasan yang hampir saling tegak lurus, yaitu arah baratdaya – timurlaut dan arah tenggara – baratlaut di sekitar Scott Plateau. Tegasan baratdaya – timurlaut mensesarkan Savu Thrust di sebelah timurlaut daerah penelitian. Metode Euler 3D Deconvolution memberikan informasi kedalaman yang mendekati hasil estimasi kedalaman analisis spektral dengan disertai informasi posisi lateralnya. Kedalaman sumber berdasarkan Euler bervariasi dari 2.4 Km – 7 Km, sedangkan kedalaman berdasarkan analisis spektral pada kisaran 2 Km – 6 Km. Pemodelan 2.5D dilakukan berdasarkan data gayaberat dengan 3 unit lapisan yaitu air laut (seabed), lapisan sedimen, dan lapisan batuan alas yang diduga berupa Thrust Fold Australian Continental Margin. Pemodelan struktur geologi bawah permukaan memperlihatkan pola struktur naik yang mendorong lapisan di atasnya (uplifted) hingga memunculkan daratan Pulau Sabu – Raijua.Kata kunci: Gayaberat, prisma akresi, sabu – raijua, struktur, uplift
Kontribusi Massa Air Tawar dari Estuari Banyuasin ke Perairan Selat Bangka pada Musim Peralihan II
Full text linkPerairan Selat Bangka banyak mendapat pasokan air tawar dari sungai-sungai di pesisir timur Provinsi Sumatera Selatan, termasuk estuari Banyuasin. Percampuran air tawar dan air laut menentukan kondisi lingkungan estuaria, khususnya pola salinitas, termasuk pembentukan habitat yang kompleks untuk komunitas tumbuhan dan hewan yang khas di dalamnya. Tujuan penelitian ini adalah mengestimasi besarnya masukan air tawar dari empat muara sungai di estuari Banyuasin ke Perairan Selat Bangka pada bulan Oktober (musim peralihan II). Pengukuran data lapangan dilakukan di 23 lokasi pada bulan Oktober 2018 menggunakan Valeport Midas CTD+ Model 606. Selanjutnya, data salinitas digunakan untuk mengetahui kisaran nilai salinitas, menganalisis nilai anomali, fraksi air tawar dan stabilitas massa air dari masing-masing sungai. Kisaran salinitas massa air di perairan Selat Bangka pada musim peralihan II adalah 2,19 sampai 31,42 psu dengan nilai anomali salinitas sebesar -30,23 sampai -1,00 psu. Masukan massa air tawar dari empat sungai adalah berbeda satu sama lain sehingga terbentuk kontur lidah salinitas di mulut estuari dan nilai salinitas bervariasi secara spasial di Selat Bangka. Fraksi air tawar yang paling dominan berasal dari Sungai Musi dengan kontribusi sebesar 31,2 %, selanjutnya diikuti Sungai Air Saleh (21,9%), Sungai Banyuasin (20,5%) dan Sungai Upang (20,3%)
Implementasi Multibeam Echosounder untuk Pengukuran dan Analisis Data Kedalaman Perairan Teluk Jakarta Berdasarkan Standar International Hydrographic Organization
Full text linkSebagian besar wilayah Indonesia adalah perairan laut dengan luas meliputi dua pertiga luas wilayah negara. Survei hidrografi menggunakan multibeam dinilai lebih efektif dan efisien dalam mengeksplorasi laut terutama kondisi dasar laut apabila dibandingkan dengan single beam echosounder. Perairan Teluk Jakarta yang dangkal dengan kegiatan maritim yang padat terutama arus lalu-lintas pelayaran memerlukan pemahaman yang kritis dan spesifik untuk menjaga keselamatan navigasi di laut. Untuk itu diperlukan standar survei dalam pengambilan dan pengolahan data multibeam yaitu aturan standar berdasarkanInternational Hydrographic Organization (IHO) yang memuat kalibrasi patch test, kalibrasi offset statik, koreksi pasang surut, dan koreksi kecepatan rambat suara dalam air dan uji kualitas data. Data multibeam yang diperoleh telah dikalibrasi dan dikoreksi dengan hasil uji kualitas pada orde spesial sebesar 97.47%. Pengukuran multibeam menghasilkan data kedalaman maksimum perairan Teluk Jakarta sebesar 10.92 m, kedalaman minimum sebesar 5.84 m, dan rata-rata kedalaman 8.26 m. Interpretasi morfologi dan topografi dasar laut membentuk alur cekungan seperti parit dengan asumsi hasil pengerukan atau erosi. Analisis data kedalaman menunjukkan terdapat area pendangkalan di sisi barat daya cekungan dengan diperoleh adanya dua titik kedangkalan
Perluasan Kinerja Akustik Limbah Kayu Batang Kelapa Sawit Termodifikasi Bahan Formaldehida
Full text linkChemical modifications for waste oil palm trunks had carried out as acoustic material. This modification was conducted in two stages. Firstly, formalization with formaldehyde solution and secondly is impregnation with melamine-formaldehyde resin. Formalization was conducted in alkaline condition (pH 10) for 3 days and 5 days. Impregnation was carried out under pressure 3 bar and 5 bar and held for an hour. For completed these modification, the samples was cured at 120oC for 10 minutes and then dried at (103±2)oC to reached moisture content of less than 6%. This modification has changed the chemical structure and the morphology of wood, as shown by the FTIR and SEM results. The samples became denser, stronger and more rigid. Furthermore, the mechanical and physical properties of modified wood are also increasing. The absorption coefficient decreases with increasing formalization time and impregnation pressure. Based on trend of absorption coefficient, BKS wood can be applicated as resonant absorber with work class from A to class B and D