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All Journal BERKALA FISIKA Journal of Energy, Material, and Instrumentation Technology
Hendri Widyandari
Jurusan Fisika, Fakultas Sains dan Matematika, Universitas Diponegoro, Semarang Universitas Diponegoro, Semarang
Control & Systems Engineering Electrical & Electronics Engineering Energy Materials Science & Nanotechnology Physics

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PEMBUATAN KOMPOSIT SERAT SERABUT KELAPA DAN RESIN FENOL FORMADEHIDE SEBAGAI MATERIAL PEREDAM AKUSTIK Kartikaratri, Yohana Maya; Subagio, Agus; Widyandari, Hendri
BERKALA FISIKA Vol 15, No 3 (2012): Berkala Fisika
Publisher : BERKALA FISIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (246.346 KB)

Abstract

The sound pollution due to noise is a one clasical problem in Indonesia. Theloudness can be reduced using the accoustic absorber. The composites of coconut fiberhas potential application as an environmental friendly accoustic absorber which is usingan agriculture waste. We reported the preparation of composite of coconut fiber as amatrix material and fenol formaldehide served as binder (coconut fiber/FF composite).The  immersion of coconut fibers  in the NaOH solution of 2% for 4 hours were caried outpriorly for improving the strengthness.The absorption coefficient (α) of the preparedcoconut fiber/FF composite was observed using two microphone impedance tube method(ISO 10534 – 2 dan ASTM E1050 – 08.   The value of tested absorption coefficient (α) allof composites samples have fulfilled the requirement. Requirement of acoustic absorbervalue of α is more than 0,15; and all of composites samples fulfilled the requirement onfrequency 752 Hz - 6400Hz.  Keyword : absorption coefficient, acoustic absorber, composite, coconut fiber, fenolformaldehid.
Immobilization of Tungsten Oxide (WO3) Material on Glass Substrate Using the Direct Spray Deposition (DSD) Method Firdaus, Iqbal; Widyandari, Hendri; Karo, Pulung Karo; Yuliandra, Rana; Fath, Yusril Al
Journal of Energy, Material, and Instrumentation Technology Vol 7 No 2 (2026): Journal of Energy, Material, and Instrumentation Technology
Publisher : Departement of Physics, Faculty of Mathematics and Natural Sciences, University of Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jemit.485

Abstract

Tungsten oxide (WO3) is a semiconductor material with promising potential for photocatalytic applications due to its visible-light response and good chemical stability. In this study, WO3 films were successfully immobilized on glass substrates using a combination of photodeposition and Direct Spray Deposition (DSD) methods. The precursor solution was prepared from ammonium paratungstate, followed by photodeposition under visible-light irradiation and deposition onto heated glass substrates using the DSD technique. The deposited films were annealed at temperatures of 500 degC, 600 degC, and 650 degC. Structural characterization was performed using X-Ray Diffraction (XRD), while surface morphology was analyzed using Scanning Electron Microscopy (SEM). XRD results revealed that increasing the annealing temperature improved the crystallinity of the films and induced phase transformations from W5O14 to W25O73 and W18O49 phases. SEM observations showed that higher annealing temperatures produced denser and more uniform film surfaces, with plate-like morphologies clearly observed at 650 degC. These findings demonstrate that annealing temperature strongly influences the structural and morphological characteristics of WO3 films prepared by the DSD method.
Co-Authors Agus Subagio Fath, Yusril Al Firdaus, Iqbal Karo, Pulung Karo Yohana Maya Kartikaratri Yuliandra, Rana