Agung Bambang Setio Utomo
Departemen Fisika FMIPA Universitas Gadjah Mada

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Pengaruh Jejari Hidrolik Stack terhadap Beda Suhu Onset pada Prime Mover Termoakustik Gelombang Berdiri Murti, Prastowo; Widyaparaga, Adhika; Setiawan, Ikhsan; Utomo, Agung Bambang Setio; Nohtomi, Makoto
Jurnal Spektra Vol 16, No 2 (2015): Spektra: Jurnal Fisika dan Aplikasinya
Publisher : Jurnal Spektra

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Abstract

AbstrakPrime mover termoakustik adalah sebuah alat yang digunakan untuk mengkonversi panas menjadi kerja dalam bentuk bunyi. Panas yang digunakan dapat berasal dari sumber panas yang tak terpakai dan melimpah seperti insenerasi alat-alat rumah sakit, pabrik industri, geotermal, dan energi surya. Untuk dapat mulai menghasilkan bunyi (kondisi onset) dibutuhkan beda suhu minimum antara ujung-ujung stack yang disebut 15(∆T)onset">   Semakin kecil beda suhu onset 15(∆T)onset">  maka suhu sumber panas yang diperlukan semakin rendah. Stack merupakan jantung dari prime mover termoakustik dan tempat terjadinya osilasi paket gas akibat adanya perbedaan suhu antara kedua sisinya. Pada penelitian ini, stack yang digunakan adalah lembaran-lembaran mesh (kasa kawat) stainless-steel yang tersusun rapat dengan jejari hidrolik 0,71 mm, 0,59 mm, 0,50 mm, dan 0,34 mm dengan panjang 4 cm, 5 cm, dan 6 cm. Dalam penelitian ini, panjang resonator adalah 1,28 m dan udara digunakan sebagai medium dengan tekanan atmosfer. Telah ditemukan bahwa jejari hidrolik stack mempengaruhi beda suhu onset 15∆Tonset">  pada prime mover termoakustik. Jejari hidrolik optimum pada 0,59 mm. Selain itu, ditemukan juga bahwa stack yang lebih panjang membutuhkan waktu yang lebih lama untuk mencapai kondisi onset dibandingkan dengan stack yang lebih pendek. Untuk mendapatkan 15∆Tonset">   lebih rendah dan waktu onset lebih cepat, perlu dilakukan penelitian tambahan tentang pengaruh beberapa paramater lain seperti panjang resonator, kalor input dan tekanan gas.Kata kunci : prime mover termoakustik, Stack mesh stainless steel, jejari hidraulik, beda suhu onset 15∆Tonset"> , waktu onset AbstractThermoacoustic prime mover is a device to convert heat into work in the form of sound. The heat used here can be obtained from unused and abundant heat source such as incineration hospital equipment, geothermal, and solar energy. A minimum onset temperature difference 15∆Tonset">  between stack ends is needed to produce the sound. Low onset temperature differences are desired when we intend to utilize low quality of heat sources. Stack is the main part of thermoacoustic prime mover in where the gas parcels oscillate due to a large temperature gradient along the stack. The stack used in this research is a pile of stainless-steels wire mesh screen with various hydraulic radius of 0.71 mm, 0.59 mm, 0.50 mm, and 0.34 mm and various stack length of 4 cm, 5 cm, and 6 cm. The length of resonator is 1.28 m and air as the working medium at atmosphere pressure is used to fill the resonator. It is found that the hydraulic radius is affecting the 15∆Tonset">  in the thermoacoustic prime mover. Hydraulic radius optimum at 0,59 mm. In addition, it is also found that longer stacks need longer time to reach the onset 15 "> condition. Investigation on the influences of other parameters, such as resonator length, heat input, and gas pressure, are required in order to have low 15∆Tonset"> .Keywords: themo-acoustic prime mover, stack mesh stainless steel screen, hydraulic radius, onset  Themperature difference 15 ∆Tonset"> , onset time.
Kajian Hasil Pengujian X-Ray Diffraction (XRD) Dan Konstanta Dielektrik Membran Polimer Kitosan/PEG4000 dengan Lithium Triflat (LiCF3SO3) Kartika - Sari; Agung Bambang Setio Utomo; Parmin Lumban Toruan; Ampala Khoryanton
Sainmatika: Jurnal Ilmiah Matematika dan Ilmu Pengetahuan Alam Vol. 18 No. 2 (2021): Sainmatika : Jurnal Ilmiah Matematika dan Ilmu Pengetahuan Alam
Publisher : Universitas PGRI Palembang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31851/sainmatika.v18i2.6717

Abstract

Synthesis and testing of chitosan/PEG4000 solid electrolyte polymer membrane with LiCF3SO3 salt as a surfactant was carried out to determine crystalline size and type of structure using X-Ray Diffraction (XRD) and dielectric constant using Electrochemical Impedance Spectroscopy (EIS). The manufacture of chitosan/PEG4000 electrolyte polymer membrane with LiCF3SO3 salt using the solution casting method. The samples used in the XRD and EIS tests were in the form of solid electrolyte polymer membranes of chitosan, chitosan/PEG4000 and chitosan/PEG4000 with LiCF3SO3 salt. XRD test showed that the crystalline size of the chitosan, chitosan/PEG4000, and chitosan/PEG4000 electrolyte polymer membranes with LiCF3SO3 salt experienced a 2θ angle shift and formed a semicrystalline phase. The peak intensity increase occurred after chitosan was added with PEG4000 with LiCF3SO3 salt. The crystalline size obtained for the electrolyte polymer membrane of chitosan, chitosan/PEG4000 and chitosan/PEG4000 salt LiCF3SO3 was 4,002 nm; 2,474 nm and 4,183 nm. Meanwhile, the type of structure produced by chitosan, chitosan/PEG4000 and chitosan/PEG4000 electrolyte polymer membranes with LiCF3SO3 salt is a semicrystalline phase. The dielectric constant for solid electrolyte polymer membranes of chitosan/PEG4000, and chitosan/PEG4000 with LiCF3SO3 salt are 3,4 and 16,6 x 103. XRD and EIS test results show that chitosan/PEG4000 polymer membrane with LiCF3SO3 salt as a surfactant can be applied as an alternative to solid electrolyte polymer secondary batteries.