cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
-
Contact Email
-
Phone
-
Journal Mail Official
-
Editorial Address
-
Location
Kota semarang,
Jawa tengah
INDONESIA
JURNAL FISIKA
Published by Universitas Negeri Semarang
ISSN : 20881509     EISSN : -     DOI : -
Core Subject : Science,
Physics
Terbit dua kali setahun pada bulan Mei dan November. Berisi tulisan yang diangkat dari hasil penelitian dan kajian konseptual Fisika Teoritik, Fisika Material, Fisika Medik, Fisika Nuklir, Fisika Komputasi dan Fisika Bumi.
Arjuna Subject : -
Articles 5 Documents
 1 
Search results for , issue "Vol 8, No 1 (2018)" : 5 Documents clear
Karakterisasi Citra CT Scan Otak Menggunakan Analisis Fraktal Berbasis Transformasi Fourier Resi Rusmawarningsih; Nurhasanah Nurhasanah; Joko Sampurno
Jurnal Fisika Vol 8, No 1 (2018)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jf.v8i1.13645

Abstract

Citra Computerized Tomography (CT) scan otak normal dan citra CT scan otak abnormal (tumor) telah dianalisis dengan menggunakan metode fraktal berbasis transformasi Fourier. Analisis dilakukan untuk menentukan tingkat kompleksitas dan densitas citra berdasarkan nilai dimensi fraktal dan intercept dari masing-masing citra. Hasil citra CT scan otak normal memiliki dimensi fraktal antara 1,355 hingga 1,5851, dan citra CT scan otak abnormal (tumor) memiliki dimensi fraktal antara 0,66106 hingga 1,2888. Citra CT scan otak normal memiliki intercept antara 25,1434 hingga 26,5707, dan citra CT scan otak abnormal (tumor) memiliki intercept antara 27,6737 hingga 31,6697. Nilai dimensi menunjukkan tingkat kompleksitas citra dan nilai intercept citra mengindikasikan nilai densitas citra. Citra CT scan otak normal memiliki tingkat kompleksitas yang lebih tinggi dan citra CT scan otak abnormal (tumor) memiliki nilai densitas yang lebih tinggi.
Kajian Struktur Serat dan Porositas Masker Udara Handika Dany Rahmayanti; Rahmawati Rahmawati; Euis Sustini; Mikrajuddin Abdullah
Jurnal Fisika Vol 8, No 1 (2018)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jf.v8i1.13966

Abstract

There are 6 brands of air masks on the market that are Evo med, Nexcare carbon, Nexcare daily, Indomaret, Borma and Evo club. All masks on the market have 3 layers. Based on the results of microscopy testing showed that the fiber diameter image of all mask brands in layer 2 is smaller than layer 1 and 3. Generally, all brands of masks show a uniform fiber size distribution. From the surface porosity measurements, Borma masks have a larger porosity than other masks in layers 1, 2 and 3 ie 60.64%, respectively; 42.95% and 63.58%. The results show that the difference in mask price in the market does not show the quality standards of different mask filters. Furthermore, the results of this study may contribute to the development of research on masks.
Analisis Homogenitas Citra Ultrasonografi Berbasis Silicone Rubber Phantom dengan GLCM Siti Fatimah; Giner Maslebu; Suryasatriya Trihandaru
Jurnal Fisika Vol 8, No 1 (2018)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jf.v8i1.14359

Abstract

Uji homogenitas merupakan salah satu kontrol kualitas ultrasonografi (USG). Pelaksanaan kontrol kualitas USG  dibutuhkan modalitas yaitu phantom ultrasound. Telah dibuat phantom ultrasound sederhana dan murah berbahan dasar silikon rubber RTV (Room Temperature Vulcanitation)  tipe 52 dengan konsentrasi katalis 2% dan 5%. Analisis homogenitas citra dilakukan dengan metode Gray Level Co-occurrence Matrix (GLCM). Pada phantom dengan konsentrasi katalis 5% didapatkan densitas  dan pada phantom konsentrasi katalis 4% didapatkan densitas  dengan selisih densitas relatif 11,65%. Berdasarkan penelitian ini didapatkan hasil semakin tinggi nilai gain yang digunakan maka homogenitas semakin rendah. Nilai homogenitas untuk phantom ultrasound dengan konsentrasi katalis 5% didapatkan 0.9945 dan phantom konsentrasi katalis 2% didapatkan nilai homogenitas 0.9940 dengan selisih homogenitas relatif 0.0543% yang menggambarkan nilai homogenitas yang tinggi untuk masing-masing phantom. Pada phantom dengan 2 densitas berbeda didapatkan nilai homogenitas 0.9881. Jika dibandingkan terhadap katalis 2%, maka selisih homogenitas relatifnya sebesar 0.648% dan terhadap katalis 5% sebesar 0.594%.
Studi Pembentukan Scale CaCO3 dan CaSO4 pada Air Formasi Sumur Minyak di Cepu, Indonesia Dante Alighiri; Cici Fatmala; Imam Syafi’i; Ervan Bagus Haditya
Jurnal Fisika Vol 8, No 1 (2018)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jf.v8i1.14496

Abstract

Scale merupakan salah satu masalah besar di pertambangan minyak bumi di Indonesia yang dapat menyebabkan sistem injeksi air pada proses pengeboran minyak bumi terhambat dan menyebabkan penurunan produksi minyak bumi. Scale CaCO3 dan CaSO4 pada dua sumur minyak di Cepu, Indonesia dianalisis dengan tujuan untuk memperkirakan besar kecenderungan air formasi dalam membentuk scale. Metode Stiff Davis digunakan untuk menentukan kecenderungan terbentuknnya scale CaCO3 dan metode Skillman, McDonald Stiff untuk menentukan kecenderungan terbentuknnya scale CaSO4. Nilai indeks stabilitas (SI) pada sumur minyak X1 sebesar 1,71 dan sumur minyak X2 sebesar 1,82. Nilai SI yang positif menunjukkan bahwa kedua sumur tersebut mempunyai kecenderungan untuk membentuk scale CaCO3. Nilai konsentrasi S pada sumur minyak X1 sebesar 58,97 meq/L dan sumur minyak X2 sebesar 57,18 meq/L. Nilai konsentrasi ion Ca2+ pada sumur minyak X1 sebesar 12,03 meq/L dan sumur minyak X2 sebesar 16,04 meq/L. Nilai konsentrasi ion SO42- pada sumur minyak X1 sebesar 0,46 meq/L dan sumur minyak X2 sebesar 0,69 meq/L. Nilai S yang lebih besar dibanding nilai konsentrasi ion Ca2+ dan SO42- menunjukkan bahwa pada kedua sumur minyak air formasi tidak menunjukkan kecenderungan terbentuknya scale CaSO4.
Optimization of Trial Wave Function in Determining the Ground State Energy of Helium Atom Yacobus Yulianto; Zaki Su'ud
Jurnal Fisika Vol 8, No 1 (2018)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jf.v8i1.14614

Abstract

The atomic ground state properties of helium, especially with regard to the ground state energy, can be studied by using various methods. One such method is the variational method. In this study, the atomic ground state energy for helium was calculated by using the trial wave function with four various parameters. The optimization process was performed by using Nelder-Mead method implied in script-code of Fortran. From calculation results, the symmetry new wave function, which meets both Pauli exclusion principle and Hund’s rule, was obtained. This obtained wave function can be written as $\Psi=0.3891exp(-1.9240r_1-0.9301r_2)+0.3891exp(-0.9301r_1-1.9240r_2)$. The atomic ground state energy obtained by this trial wave function is in good agreement with experimental energy, i.e.  eV (with discrepancy of  from experimental result). It can be indicated that the obtained trial wave function is quite good in explaining the atomic ground state properties of helium. In addition, the Nelder-Mead method used in this study is quite good in optimizing the equation with four variation parameters.The atomic ground state properties of helium, especially with regard to the ground state energy, can be studied by using various methods. Such method is the variational method. In this study, the atomic ground state energy for helium was calculated by using the trial wave function with four various parameters. The optimization process was performed by using Nelder-Mead method implied in script-code of Fortran. From calculation results, the symmetry new wave function, which meets both Pauli exclusion principle and Hund’s rule, was obtained. This obtained wave function can be written as . The atomic ground state energy obtained by this trial wave function is  eV (with discrepancy of  from the experimental energy), where this result is in good agreement with the experimental energy. It can be inferred that the obtained trial wave function is quite good in explaining the ground state properties of helium atom. In addition, the Nelder-Mead method used in this study has good capability in optimizing the equation with four variation parameters.

Page 1 of 1 | Total Record : 5

 1 

Filter by Year

2018 2018


Reset
Filter By Issues
All Issue Vol 13, No 1 (2023) Vol 12, No 2 (2022) Vol 12, No 1 (2022) Vol 11, No 2 (2021) Vol 11, No 1 (2021) Vol 10, No 2 (2020) Vol 10, No 1 (2020) Vol 9, No 2 (2019) Vol 9, No 1 (2019) Vol 8, No 2 (2018) Vol 8, No 1 (2018) Vol 7, No 2 (2017) Vol 7, No 1 (2017) Vol 5, No 2 (2015) Vol 5, No 1 (2015) Vol 4, No 2 (2014) Vol 4, No 1 (2014) Vol 3, No 2 (2013) Vol 3, No 1 (2013) Vol 1, No 2 (2011) Vol 1, No 1 (2011) More Issue