cover
Contact Name
Ali Khumaeni
Contact Email
khumaeni@fisika.fsm.undip.ac.id
Phone
+62247474754
Journal Mail Official
jpa@live.undip.ac.id
Editorial Address
Department of Physics Faculty of Science and Mathematics Diponegoro University Jl Prof Soedharto SH, Tembalang, Semarang, Indonesia
Location
Kota semarang,
Jawa tengah
INDONESIA
Journal of Physics and Its Applications
Published by Universitas Diponegoro
ISSN : -     EISSN : 26225956     DOI : 10.14710
Core Subject : Science,
Journal of Physics and Its Applications (JPA) (e-ISSN: 2622-5956) is open access, International peer-reviewed journal that publishes high-novelty and original research papers and review papers in the field of physics including Radiation Physics, Materials, Geophysics, Theoretical Physics, Instrumentation and Electronics, Medical Physics, Biomedical Physics, Chemical Physics, Mathematical Physics, and Applied Physics. The JPA publishes two issues annually (May and November). The journal is published by Department of Physics, Faculty of Science and Mathematics, Diponegoro University, Indonesia.
Articles 5 Documents
Search results for , issue "Vol 3, No 2 (2021): May 2021" : 5 Documents clear
Evaluation and Implementation of Otsu and Active Contour Segmentation in Contrast-Enhanced Cardiac CT Images Arvi Razanata; Prawito Prajitno; Djarwani Soeharso Soejoko
Journal of Physics and Its Applications Vol 3, No 2 (2021): May 2021
Publisher : Diponegoro University Semarang Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jpa.v3i2.10712

Abstract

The CT cardiac acquisition process is usually conducted by using an additional image with contrast medium that is injected inside the body and reconstructed by a radiologist using an integrated CT Scan software with the aim to find the morphology and volume dimension of the heart and coronary arteries. In fact, the data obtained from the hospital are raw data without segmented contour from a radiologist. For the purpose of automation, dataset is needed to be used as input data for further program development. This study is focused on the evaluation of the segmentation results of CT cardiac images using Otsu threshold and active contour algorithm with the aim to make a dataset for the heart volume quantification that can be used interactively as an alternative to integrated CT scan software. 2D contrast enhanced cardiac CT from 6 patients using image processing techniques was run on Matlab software. Of the 689 slices that was used, as many as (73.75 ± 19.41)%of CT cardiac slices have been segmented properly, (19.15 ± 19.61)%of the slices that were segmented included the spine bone, (1.36 ± 0.98)%of the slices did not include all region of the heart, (16.58 ± 15.26)%of the slices included other organs with the consistency from the measurement proven from inter-observer variability to produce r = 0,9941.The result is due to the geometry influence from the diameter of the patient’s body thickness that tends to be thin.
Identification of Landslide with Resistivity Method at Candi Industrial Area, Ngaliyan, Semarang Nuriyana Muthia Sani; Agus Setyawan; Rahmat Gernowo
Journal of Physics and Its Applications Vol 3, No 2 (2021): May 2021
Publisher : Diponegoro University Semarang Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jpa.v3i2.10674

Abstract

Landslides can be occurred in almost every natural slope or artificial slope slowly or suddenly with or without any prior signs. The main reason for slope collapse is the increase in shear stress in the landslide, the decrease in shear strength, or both. Landslide problems can result in loss of life and property, damage to the environment, infrastructure, public facilities, and disrupt livelihood generally. Landslides can be detected by exploration of the subsurface. The geoelectrical method is one of the geophysical methods to know the change of resistance of a type of rock layer below ground level. The research aims to interpret the lithology of the subsurface in the Candi Industrial Area, Ngaliyan, Semarang using Schlumberger configuration. The results of measurements are voltage and electric current to calculate the apparent resistivity value processed by IP2Win software to determine the lithology and the slip surface area. The results present that lithology in the research area consists of sand clay, clay, and sandstone. The results showed that the locations of landslide-prone areas lie at the contact between sand clay and clay with that area at a depth of between 19.95 – 31.62 m there is one difference in the resistivity value which can be assumed to be a slip surface.The result of the research can be used to make policy rules of landslide mitigation.
Characterization of Landslide geometry using Seismic Refraction Tomography in the GayoLues, Indonesia Muzakir Zainal; Badrul Munir; Marwan Marwan; Muhammad Yanis; Akmal Muhni
Journal of Physics and Its Applications Vol 3, No 2 (2021): May 2021
Publisher : Diponegoro University Semarang Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jpa.v3i2.10601

Abstract

Landslides are the most common geological phenomenon in Indonesia.The event is damage to public infrastructure, and fatalities was a big impact. Therefore, mapping the geometry of landslides is a part of the mitigation effort possible by geophysical methods. In this research, we applied seismic refraction tomography (SRT) to study the geometry of the sliding zone from the landslide event.TheNational Disaster Management Authority reported that the area was frequently occurring landslide disaster, i.e. 2018, 2019 and 2020 which caused the public infrastructure and obstructed the road access from the central to the west of Aceh. The SRT was measured in two profileslong the road.Data measurements were conducted on the side of the Babahrot - GayoLues road section that had experienced landslides.Measurements were made using the Seismograph PASI 16S24-P and 24 geophones to obtain a 92-meterlong profile with 2 meter spacing between the geophones. P-wave velocity data modeling is done using ZondST2D software.The results of modeling profiles 1 and 2 describe three different subsurface layers.The SRT profile 1 model consists of slate (0.2 - 0.7 km/s), clay (0.8 - 1.3 km/s), and sandy clay (1.4 - 1.9 km/s).While, the model of profile 2 consists of slate (0.5 - 1.0 km/s), clay (1.1 - 1.6 km/ s), and sandy clay (1.7 - 2.5 km/s).The contrasting wave velocity model shows that the SRT method can be used in landslide studies as a reference in determining the mechanism of the landslide system.
Comparison of I-V Curves Between the Experiment of Corona Discharge on Gradient Line-To-Plane (GL-P) Configuration and The Mathematical Approach Susilo Hadi; Asep Yoyo Wardaya; Zaenul Muhlisin; Jatmiko Endro Suseno; Pandji Triadyaksa; Ali Khumaeni; Muhammad Nur
Journal of Physics and Its Applications Vol 3, No 2 (2021): May 2021
Publisher : Diponegoro University Semarang Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jpa.v3i2.10491

Abstract

Research has been conducted on the comparison of the I-V characteristic curve between mathematical study and experiment of the generation of negative DC corona discharge in the Gradient Line-to-Plane (GL-P) electrode configuration. The reason for this research is to calculate the suitability of the corona discharge electrical current between the mathematical and experimental study. The active electrode used has length 2 cm and height 4 cm. This research is conducted with variations in the sharpness angle of the active electrode (θ) 300, 450, and 600 and variations in the distance between the electrodes () 2 cm, 3 cm, and 4 cm. The mathematical formulation of the value of the corona discharge electrical current in the configuration of the GL-P electrode is obtained by using the geometric concept approach, which is the formulation of the capacitance value of the ordinary electrical circuit, with the addition of the multiplication factor value k in the sharp area of the active electrode, because in that area the greatest plasma flow distance is obtained. The value of the multiplication factor  is obtained by fitting the curve between mathematical study and experiments. The I-V curve between the mathematical study and the corona discharge generation experiment has a high degree of similarity with the smallest percentage contacting point of 37.50%.The value of the multiplication factor  is influenced by the sharpness angle of the active electrode shape and the distance between the electrodes.
Improving water absorption time and the natural silk strength (Bombyx Mori) using atmospheric dielectric barrier discharge plasma Zaenul Muhlisin; Muhammad Adrian Lathif; Fajar Arianto; Pandji Triadyaksa
Journal of Physics and Its Applications Vol 3, No 2 (2021): May 2021
Publisher : Diponegoro University Semarang Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jpa.v3i2.10658

Abstract

This researchaimed to obtain Dielectric Barrier Discharge plasma discharge characteristics with and without the placement of natural silkBombyx Mori on one of the electrodes. Furthermore, the strength and the water absorption time of the irradiated silk samples will be analyzed.  Plasma discharge is generated by connecting electrodes of point-to-plane configuration with a sheet of glass inserted on the plane electrode at atmospheric conditions. The characterization of plasma discharge, either with or without the natural silk samples' placement on the plane electrode, was performed by increasing A.C.'s high voltage power source to reach arch discharge. Theelectrode spacing varied from 0.7 cm to 2.5 cm with a 0.3 cm increment. Sample irradiation was performed using cold plasma for 5, 15, and 30 minutes respectively. Placing or not placing the natural silk samples on the plane electrode will increase the plasma's discharge current and increase the high voltage. Moreover, increasing the distance between the electrodes and placing the sample on the plane electrode decreases the discharge current. Using Scanning Electron Microscopy, it was found that increasing plasma irradiation time on samples decreases the silk thread'sdiameterand shortening its water absorption time. The strength of irradiated fabric was reduceduntil 15 minutes of irradiation. However, at 30 minutes of irradiation, there was an increase in sample thickness compared to control samples.

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