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Microwave Effects on Microstructure of Ceramics Sudianaa, I Nyoman Sudianaa; Mitsudob, Seitaro; Inagakib, Shunsuke; Sakob, Katsuide
Majalah Ilmiah Pendidikan Matematika dan Ilmu Pengetahuan Alam Vol 1, No 1 (2014)
Publisher : Universitas Halu Oleo

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Abstract

The sintering and microstructure evolution of alumina ceramic sintered by a wide range microwave were investigated. Bulk density were calculated by using Archimedes method while the grain size measurements were used to correlate sintering with grain growth was observed by electron microscope. The microwave effects such as an enhancement of densification and shorter time of processing of microwaves compared to conventional case have been found and reported in previous paper. There was also showed microwave frequency dependency of alumina`s densification.  Unfortunately there is no satisfactory theory to explain the phenomena. However the electric field inside sample during electromagnetic heating is believed as the main factor. In this paper further investigation of microwave effect on alumina properties was reported. The effect of microwave on microstructure of alumina is evaluated.  Grain evolution for each sintering methods were evaluated by using image processing on the scanning electron microscopy’s photos of fracture and grinded surfaces of samples. There showed that microstructure of sintered alumina is dependent on the microwave frequencies. Some possible mechanisms were also discussed.
Identifikasi Gugus SiHx (x=1, 2 dan 3) pada Silikon Berpori dari Substrat Si (111) Tipe-P Sudiana, I Nyoman
Jurnal Fisika FLUX Vol 7, No 2 (2010): Jurnal Fisika Flux Edisi Agustus 2010
Publisher : Lambung Mangkurat University Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/flux.v7i2.3084

Abstract

The study of identification of functional group SiHx (x=1, 2, 3) to typepSi (111) made by anodizatied silicon wafer in 0,3 ohm-cm hydrofluoric (HF) hasbeen conducted. The objective of the research is to determine the effects of HFconcentrations and anodization time on PS functional groups. HF concentrationwas varied to 10%, 20%, 30% and 40% the anodization time was varied to 10,20, 40 and 60 minutes respectly. While the anodization it was used a magneticstirrer to keep the homogenity of the solution. The existence of SiH groups ischaracterized by FTIR spectrofotometer. The results shows that SiH groupfunctional appears around absorbtion area of 2112-2100 cm-1, 920-890 cm-1and 856 cm-1. Where as the longer time anodization the fewer of SiH groupsformed.
Efek Microwave pada Proses Deasetilasi Kitin dari Limbah Cangkang Udang Zaeni, Muhammad; Fuadah, Badrotul; Sudiana, I. N.
Jurnal Aplikasi Fisika Vol 13, No 2 (2017): JURNAL APLIKASI FISIKA
Publisher : Jurusan Fisika FMIPA UHO

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Abstract

A research about “Microwave Effect on the Chitin Deacetylation Process of Shrimp-Shell Waste (Panaeus merguensis) “ is done. This research aims to decrease the reaction time of acetyl group determination and to get glucosamine hydrochloride that fit the standard. In this research, NaOH 50% is used, while the radiation duration is varied. Microwave radion durations are under 30 minute i.e. 3,7,11,15 minutes with 450 watt power to examine the effectivity of microwave technology compared to conventional method. FTIR  (Fourier Transform Infrared)  test results show that the highest Deacetylation Degree (DD) of chitosan 62,72%, is reached at 15 minutes of microwave radiation duration, that equivalent with deacetylased chitosan by conventional method that is 61,78%. Chitosan then undergoes the making process of glucosamine hydrochloride by using HCl 37%. The characterization result show that glucosamine hydrochloride has a good solubility in water, melting point of 190ºC, FTIR spectrum of glucosamine hydrochloride shows  absorption bands that fit the standard glucosamine hydrochloride and XRD test result show that theb synthesized crystal still has a low crystalinity. Keyword: microwave, chitin, chitosan, deacetylation degree, glucosamine hydrochloride.
POROSITAS MIKROSTRUKTUR SILIKA KERAMIK HASIL EKSTRAKSI DARI LIMBAH SEKAM PADI YANG DISINTERING DENGAN MICROWAVE Endang S, Prima; Trisnawati, Trisnawati; Sudiana, I. N.
Jurnal Aplikasi Fisika Vol 13, No 2 (2017): JURNAL APLIKASI FISIKA
Publisher : Jurusan Fisika FMIPA UHO

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Abstract

An experiments have been conducted on the characterization of ceramic silica microstructures extracted from rice husks. The aim of this research is to observe the change of ceramic silica microstructure extracted from rice husk ash after sintered by using microwave. Rice husk ash first extracted using HCl 1M and NaOH 2M, then drying and molding. Ceramic silica is sintered by using microwave and electric furnace at temperature range 1000˚C-1600˚C. Characterization of ceramic silica using scanning electron microscope (SEM). The results of scanning electron microscope (SEM) show that in the sintering process using microwave the surface of silica ceramic sample is form solid granulars and  pores rapidly reduced. While the results of scanning electron microscope (SEM) using the furnace along with rising temperature, showing microstructure ceramic silica samples at each temperature is almost the same but slower pore reduction. Keywords: rice husk, extraction, sintering, microwave, imageJ software, microstructure. 
Simulasi Efek Microwave Pada Pemanasan Beberapa Komponen Dasar Bio-Oil Wayan Trimawiasa; I Nyoman Sudiana; La Aba
BULETIN FISIKA Vol 23 No 1 (2022): BULETIN FISIKA February Edition
Publisher : Departement of Physics Faculty of Mathematics and Natural Sciences, and Institute of Research and Community Services Udayana University, Kampus Bukit Jimbaran Badung Bali

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/BF.2022.v23.i01.p05

Abstract

An investigation of the microwave effect has been carried out by simulating heating the basic components of bio oil. This research aims to produce a heating model and energy distribution of oleic acid and stearic acid component materials. The cylindrical material is placed in a cavity-shaped heating applicator using a microwave excitation frequency of 2.45 GHz through a single waveguide TE10 mode. Numerical solution using time-domain solver and transient solver succeeded in simulating the heating model of the dielectric material with the results of the energy distribution depending on the complex permittivity of the material.
A Prototype Fabrication of Sensitive Porous Silicon NOx (x=1,2) Gas Sensor Nyoman Sudiana; Muhammad Anas; Muhammad Jahiding Hafid
Jurnal ILMU DASAR Vol 11 No 1 (2010)
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Jember

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Abstract

A prototype of (porous silicon (PS) based) NO(x=1.2) gas sensor based on porous silicon (PS) (operated at room temperature) has been fabricated. The sensor could be operated at room temperature. The (PS) basic material for the material sensor ( i.e. PS) was fabricated in the previous research by varying (parameter of the HF concentrations) concentrations of HF (what is HF?) and (the anodization time) time of anodizations. Its structure, as well as its optic, has been characterized. In this research, we did electrical characterization of PS to find its conductivity. The conductivity of PS is important because PS, as a sensor, utilizes the changes of conductivity when it is passed by NO(x=1.2). (The influence of these parameters on I-V characteristics of the PS and on the sensor performances has been studied in detail) The changes of electrical current because of the varying NO concentrations with time were measured using a current measuring system, then plotted. The result (shows) showed that the sensor could detect NO (and NO) gasses ranging from 16 ppb to 200 ppb and NO gas ranging from 12 ppb to 200 ppb, respectively at room temperature (28C) and at adjusted currents ranging from 20 to 800 μA. The result also showed that the sensor was not completely reversible for NO. xxx22ox 
MICROWAVE PROCESSING OF SILICA FROM RICE HUSK I Nyoman Sudiana
Jurnal Aplikasi Fisika Vol 11, No 1 (2015): JURNAL APLIKASI FISIKA
Publisher : Universitas Halu Oleo

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Abstract

Penelitian ini untuk membuat silica keramik dengan menggunakan energi mikrowave. Silika diproduksi dari sekam padi yang diperoleh di persawahan di Sulawesi Tenggara. Silika yang diperoleh memiliki kemurnian rata-rata 93.8 %. Silika ini di buat pellet lalu disinterring sampai suhu 1100 oC untuk mendapatkan keramik dengan kualitas tinggi. Mikrowave yang digunakan dari hasil modifikasi oven microwave komersial. Hasilnya dibandingkan dengan pemanasan biasa (dengan tanur listrik). Hasil ekperimen menunjukkan perbedaan yang signifikan dibandingkan keramik hasil pemanasan biasaterhadap sifat-sifat keramik. Ini menunjukkan bahwa ada ‘microwave effect’ terhadap silika selama sintering.
Kristalisasi Silika Xerogel dari Sekam Padi M. Zamrun F; I. N. Sudiana
Jurnal Aplikasi Fisika Vol 12, No 1 (2016): JURNAL APLIKASI FISIKA
Publisher : Universitas Halu Oleo

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Abstract

The study to determine crystallinity of silica derived from rice husk ash during sintering by electric furnace and microwave was successfully performed. The crystallinity was determined by using X-Ray Diffraction for every sintering temperature step. The XRD analysis revealed that crystallinity of microwave sintered silica faster than that of electric furnace sintered ones. It indicates that the microwaves have affected atomic diffusion during sintering which result in enhancement of silica crystallization.
Efek Microwave terhadap Karakteristik Fisis Briket dari Sekam Padi Asmijar Nurlette; I Nyoman Sudiana; Wa Ode Sitti Ilmawati
Jurnal Aplikasi Fisika Vol 14, No 1 (2018): JAF, Februari 2018
Publisher : Universitas Halu Oleo

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Abstract

Telah dilakukan penelitian tentang efek microwave terhadap karakteristik fisis briket dari sekam padi. Pengujian ini menggunakan analisis nilai kalor dan uji nyala. Tujuan dari penelitian ini adalah untuk menentukan pengaruh microwave terhadap karakteristik fisis. Briket sekam padi dibuat dengan menambahkan tepung tapioca sebagai bahan perekatnya dengan komposisi 10% dari total massa sampel. Ukuran butiran sekam padi yang digunakan sebesar 60 mesh. Sampel dicetak dengan menggunakan cetakan silinder dengan diameter 1,8 cm dengan kekuatan pressing alat kompaksi sebesar 100 kg/cm³. Briket dikeringkan dalam microwave dengan variasi daya microwave 150W, 300W, 500W, 600W dan 800W dengan waktu pemanasan masing-masing selama 30 detik. Pengujian kualitas bahan briket meliputi penentuan analisis nilai kalor dan uji nyala briket. Hasil penelitian menunjukkan bahwa semakin besar daya microwave mengakibatkan perubahan nilai kalor briket sekam padi, dimana nilai kalor optimum diperoleh pada daya 150W sebesar 2122,712 kal/gram  dan terendah sebesar 380,507 kal/gram pada daya 800W. Demikian pula apa bila daya microwave yang semakin besar mengakibatkan temperatur pembakaran/nyala yang semakin kecil, dimana temperatur pembakaran optimum diperoleh pada daya microwave 150W sebesar 5450C dan temperatur pembakaran/nyala terendah sebesar 4680C diperoleh pada daya microwave 800W.
EFEK MICROWAVE PADA PADUAN SILIKA (SiO2) DARI SEKAM PADI DAN ALPHA ALUMINA (-Al2O3) I Nyoman Sudiana; Muhammad Zamrun Firihu; La Aba; Lina Lestari; Prima Endang Susilowati
Jurnal Aplikasi Fisika Vol 13, No 2 (2017): JURNAL APLIKASI FISIKA
Publisher : Universitas Halu Oleo

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Abstract

Research on the effects of microwave on the composite of silica (SiO2) from rice husk and alpha alumina (α-Al2O3) had been conducted. This study aims to determine the effect of microwave on the density and pore volume percent of silica alumina ceramic. Alpha alumina powder silica powder was mixed with a variation of 75%:25%, 85%:15% and 95%:5%, then added  with PVA as gluten as much as 3% wt. Each sample was compacted with a pressure of 4 tons and sintering with temperature variations of 900, 1000 and 1100 oC. The results of characterization using microwave sintering was better than using a sintering furnace. Shown by the increase in density and decrease in percent pore volume faster in the microwave was at a ratio of 85%:15% and temperatures 1100oC microwave sintering has the density of 3.241 g /cm3 and a percent pore volume of 9.892% while the sintering furnace has a density value of 3.013 g /cm3 and the pore volume and percent of 16.238%. Keywords : microwave sintering, alumina, silica, density, pore.