Harjana Harjana
Universitas Sebelas Maret (UNS)

Published : 6 Documents
Articles

Found 6 Documents
Search

Kinerja Serapan Bunyi Komposit Ampas Tebu Berdasarkan Variasi Ketebalan dan Jumlah Quarter Wavelength Resonator terhadap Kinerja Bunyi Kristiani, Restu; Yahya, Iwan; Harjana, Harjana
Jurnal Fisika dan Aplikasinya Vol 10, No 1 (2014)
Publisher : Jurnal Fisika dan Aplikasinya

Show Abstract | Original Source | Check in Google Scholar | Full PDF (594.904 KB)

Abstract

Telah dilakukan pengujian kinerja serapan bunyi dari komposit ampas tebu dikaitkan dengan pengaruh konfigurasi ketebalan dan konfigurasi quarter wavelength resonator. Pengujian kinerja dilakukan secara eksperimen menggunakan tabung impedansi dua mikrofon mengacu kepada prosedur ASTM E-1050-98.Dalam penelitian ini dilakukan variasi tiga dan enam konfigurasi resonator serta variasi air cavity yakni 1, 2, dan 3 cm. Hasil penelitian menunjukkan bahwa komposit ampas tebu dengan konfigurasi enam resonator memiliki kinerja serapan bunyi terbaik. Adapun pengaruh ketebalan sampel adalah menggeser penyerapan bunyi efektif pada frekuensi rendah sementara penggunaan resonator efektif akan melebarkan rentang frekuensi penyerapan sehubungan dengan bertambahnya mekanisme redaman viskous bersamaan dengan mekanismeserapan resonasi.
Analisis Citra Simulator Unit Radiologi RSUD dr. Moewardi Surakarta Damaringtyas, Zening; Yunianto, Mohtar; Harjana, Harjana
Jurnal Fisika dan Aplikasinya Vol 10, No 2 (2014)
Publisher : Jurnal Fisika dan Aplikasinya

Show Abstract | Original Source | Check in Google Scholar | Full PDF (395.249 KB)

Abstract

Telah dilaksanakan penelitian tentang analisis citra simulator unit radiologi RSUD dr. Moewardi Surakarta. Citra yang dihasilkan simulator sebagai verifikasi lapangan dalam radioterapi. Citra tersebut akan ditajamkan sehingga batasan luas lapangan semakin jelas. Citra diolah dengan metode deteksi tepi yang telah diprogram melalui perangkat lunak Matlab. Tampilan program berupa GUI (Graphic User Interface) sehingga mudahdigunakan. Selain metode deteksi tepi, program juga melakukan perhitungan aksis lapangan penyinaran. Perhitungan aksis lapangan penyinaran berdasarkan informasi yang diperoleh pada citra meliputi faktor magnifikasi dan axis penyinaran. Hasil dari penelitian ini adalah suatu program yang dapat mendeteksi tepi citra secara tepat dan sesuai gambar asli dan dapat menghitung besarnya aksis lapangan penyinaran secara teliti.
Pengaruh Sisipan Resonator Celah Sempit pada Serapan dan Respon Spasial Quadratic Residue Diffuser Devitasari, Erna Y.; Chorida, Arifatul; Muqowi, Eki; Haryanti, Nining; Harjana, Harjana; Yahya, Iwan
Jurnal Fisika dan Aplikasinya Vol 10, No 1 (2014)
Publisher : Jurnal Fisika dan Aplikasinya

Show Abstract | Original Source | Check in Google Scholar | Full PDF (1025.355 KB)

Abstract

Telah dilakukan analisis pengaruh sisipan resonator celah sempit terhadap perubahan kinerja serapan danrespon spasial quadratic residue diffuser (QRD). Pengujian serapan elemen diffuser dilaksanakan denganmenggunakan teknik tabung impedansi dua mikrofon, sementara simulasi respon spasial dikerjakan denganmenggunakan perangkat lunak AFMG Reflex pada tiga kondisi sisipan berbeda. Hasil pengujian menunjukkanbahwa sisipan resonator celah sempit pada rancangan standar QRD dapat memicu peningkatan koefisen serapanyang bersifat akumulatif dan berdampak pada peningkatan respon spasial omnidireksional pada bentangfrekuensi tinggi di atas 800Hz. Sifat yang demikian menunjukkan bahwa modifikasi QRD standar dengansisipan resonator celah sempit memiliki potensi yang sangat baik untuk aplikasi pada ruangan dimana terdapatkebisingan yang bersumber dari mesin atau piranti yang mengandung komponen yang berputar (rotatingmachinery).
Development of Three-Tier Diagnostics Instruments on Students Misconception Test in Fluid Concept Irwansyah, Irwansyah; Sukarmin, Sukarmin; Harjana, Harjana
Jurnal Ilmiah Pendidikan Fisika Al-Biruni Vol 7, No 2 (2018): Jurnal Ilmiah pendidikan Fisika Al-Biruni
Publisher : UIN Raden Intan Lampung, Indonesia

Show Abstract | Original Source | Check in Google Scholar | Full PDF (267.179 KB)

Abstract

The purpose of this research was to know the validity and reliability of instrument three-tier diagnosis to identify the students’ misconception in fluid concept. The stages of development research that used in this research were (1) The first research and collecting information, (2) planning and designing of development (3) validity and product evaluation. The instrument of the test was tested on 98 students of 3 schools. The instrument has been developed and categorized effectively because it has a valid category with the Aiken validity index value> from table V (0.75) and the reliability of the instrument has a value of 0.96 with a high category. The instrument of three-tier test that developed was able to identify the students' comprehension in students' concept and students' misconception. There are 27,58% students comprehend the concept, 45,29% students did not comprehend the concept, 24,74% students showed that misconception and 2,36% students experienced errors
Development of Three-Tier Diagnostics Instruments on Students Misconception Test in Fluid Concept Irwansyah, Irwansyah; Sukarmin, Sukarmin; Harjana, Harjana
Jurnal Ilmiah Pendidikan Fisika Al-Biruni Vol 7, No 2 (2018): Jurnal Ilmiah pendidikan Fisika Al-Biruni
Publisher : UIN Raden Intan Lampung, Indonesia

Show Abstract | Original Source | Check in Google Scholar | Full PDF (267.179 KB)

Abstract

The purpose of this research was to know the validity and reliability of instrument three-tier diagnosis to identify the students’ misconception in fluid concept. The stages of development research that used in this research were (1) The first research and collecting information, (2) planning and designing of development (3) validity and product evaluation. The instrument of the test was tested on 98 students of 3 schools. The instrument has been developed and categorized effectively because it has a valid category with the Aiken validity index value> from table V (0.75) and the reliability of the instrument has a value of 0.96 with a high category. The instrument of three-tier test that developed was able to identify the students comprehension in students concept and students misconception. There are 27,58% students comprehend the concept, 45,29% students did not comprehend the concept, 24,74% students showed that misconception and 2,36% students experienced errors
Development of Three-Tier Diagnostics Instruments on Students Misconception Test in Fluid Concept Irwansyah, Irwansyah; Sukarmin, Sukarmin; Harjana, Harjana
Jurnal Ilmiah Pendidikan Fisika Al-Biruni Vol 7, No 2 (2018): Jurnal Ilmiah pendidikan Fisika Al-Biruni
Publisher : UIN Raden Intan Lampung, Indonesia

Show Abstract | Original Source | Check in Google Scholar | Full PDF (267.179 KB)

Abstract

The purpose of this research was to know the validity and reliability of instrument three-tier diagnosis to identify the students’ misconception in fluid concept. The stages of development research that used in this research were (1) The first research and collecting information, (2) planning and designing of development (3) validity and product evaluation. The instrument of the test was tested on 98 students of 3 schools. The instrument has been developed and categorized effectively because it has a valid category with the Aiken validity index value> from table V (0.75) and the reliability of the instrument has a value of 0.96 with a high category. The instrument of three-tier test that developed was able to identify the students' comprehension in students' concept and students' misconception. There are 27,58% students comprehend the concept, 45,29% students did not comprehend the concept, 24,74% students showed that misconception and 2,36% students experienced errors