Denisa Eka Febrianti, Alfi Tranggono Agus Salim, W. Rezika, Muhamad Azwar Annas, S. Suyatno
The noise pollution in residential areas adjacent to double-track railways can significantly disturb the comfort and well-being of residents. The noise originates from passing trains on these double-track railways. The research problem aims to compare the noise levels in the residential area with the standard noise threshold and evaluate the effectiveness of a noise barriers based on waste material called sustainable noise barrier. The effectiveness of reducing noise levels for communities residing near the dual railway lines. The sustainable noise barrier is constructed using waste cardboard and sawdust as sound absorbers for reducing noise from passing trains. The objective of the research is to analyze the noise levels in the residential areas near the dual railway lines, referring to the noise threshold value specified in Kep.MenLH No.48 of 1996, which is 55 dBA. Additionally, the research aims to assess the effectiveness of the sustainable noise barrier in mitigating noise pollution in these residential areas. The research employs a quantitative experimental method, following the SNI 8427 of 2017 standard for measuring residential noise pollution and determining the sustainable noise barrier's effectiveness using Insertion Loss (IL) and Sound Transmission Loss (STL) measurements in both laboratory-scale and existing conditions (alongside the double-track railways). The research findings indicate that the noise levels in residential areas adjacent to dual railway lines exceed the threshold value, reaching 78.08 dBA. However, the sustainable noise barrier proves to be effective in reducing noise pollution by 27 dB at a frequency of 1,000 Hz in the residential areas neighboring the double-track railways. This research suggests that limiting noise disturbances in residental areas bordering railway lines is one solution with noise barriers.
{"title":"Effectiveness of Noise Barriers Based on Waste Materials in Case Study of Residential Noise Due to Double-Track Railways","authors":"Denisa Eka Febrianti, Alfi Tranggono Agus Salim, W. Rezika, Muhamad Azwar Annas, S. Suyatno","doi":"10.14710/jpa.v6i1.19992","DOIUrl":"https://doi.org/10.14710/jpa.v6i1.19992","url":null,"abstract":"The noise pollution in residential areas adjacent to double-track railways can significantly disturb the comfort and well-being of residents. The noise originates from passing trains on these double-track railways. The research problem aims to compare the noise levels in the residential area with the standard noise threshold and evaluate the effectiveness of a noise barriers based on waste material called sustainable noise barrier. The effectiveness of reducing noise levels for communities residing near the dual railway lines. The sustainable noise barrier is constructed using waste cardboard and sawdust as sound absorbers for reducing noise from passing trains. The objective of the research is to analyze the noise levels in the residential areas near the dual railway lines, referring to the noise threshold value specified in Kep.MenLH No.48 of 1996, which is 55 dBA. Additionally, the research aims to assess the effectiveness of the sustainable noise barrier in mitigating noise pollution in these residential areas. The research employs a quantitative experimental method, following the SNI 8427 of 2017 standard for measuring residential noise pollution and determining the sustainable noise barrier's effectiveness using Insertion Loss (IL) and Sound Transmission Loss (STL) measurements in both laboratory-scale and existing conditions (alongside the double-track railways). The research findings indicate that the noise levels in residential areas adjacent to dual railway lines exceed the threshold value, reaching 78.08 dBA. However, the sustainable noise barrier proves to be effective in reducing noise pollution by 27 dB at a frequency of 1,000 Hz in the residential areas neighboring the double-track railways. This research suggests that limiting noise disturbances in residental areas bordering railway lines is one solution with noise barriers.","PeriodicalId":280868,"journal":{"name":"Journal of Physics and Its Applications","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139232662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In external beam radiation therapy, the percentage depth dose (PDD) is a main factor for estimation of patient’s dose and dose distribution in target volume, therefore its accurate estimation is important. The purpose of this article is to compare PDDs with the published PDDs of different authors along central axis at different depths and field sizes for cobalt-60 (Co-60) radiotherapy machine at a regional cancer hospital Pakistan. A dedicated water phantom was used for estimation of PDDs at different depths and different field sizes, for Theratron phoenix Co-60 machine. It was observed that for 10×10 cm2 filed size of Co-60 beam mean percent variation in measured PDDs and published PDDs by different authors was -0.29% to 1.13%, which was within acceptable limit of ± 2%. However, for one author who used semi-empirical equation for PDDs calculation, the mean percent variation between measured PDDs and that of the author was -3.23%, 4.69% and 5.88% for 10×10 cm2, 25×25 cm2 and 30×30 cm2 field sizes of Co-60 beam respectively, which were within acceptable limit of ±10%. A noticeable increase in PDDs was observed with increase of the field size at given depth which shows obvious contribution of secondary scattered radiation. Also measured PDDs were well matched with that of published PDDs of most of the authors i.e. ± 2%, but the measured PDDs were moderately matched with that of PDDs for only one author for some field sizes and some depths i.e. ±10%, which need to be rectified by taking more such data.
{"title":"Comparison of Percentage Depth Doses with the Published Data for Co-60 Radiotherapy Machine at a Regional Cancer Hospital","authors":"Javaid Ali, Muhammd Sohail, Abdul Samad, Israr Ahmad, Hafeezullah Soomro, Ghufran Biradar, Irum Naz, Imadullah Tariq","doi":"10.14710/jpa.v6i1.20537","DOIUrl":"https://doi.org/10.14710/jpa.v6i1.20537","url":null,"abstract":"In external beam radiation therapy, the percentage depth dose (PDD) is a main factor for estimation of patient’s dose and dose distribution in target volume, therefore its accurate estimation is important. The purpose of this article is to compare PDDs with the published PDDs of different authors along central axis at different depths and field sizes for cobalt-60 (Co-60) radiotherapy machine at a regional cancer hospital Pakistan. A dedicated water phantom was used for estimation of PDDs at different depths and different field sizes, for Theratron phoenix Co-60 machine. It was observed that for 10×10 cm2 filed size of Co-60 beam mean percent variation in measured PDDs and published PDDs by different authors was -0.29% to 1.13%, which was within acceptable limit of ± 2%. However, for one author who used semi-empirical equation for PDDs calculation, the mean percent variation between measured PDDs and that of the author was -3.23%, 4.69% and 5.88% for 10×10 cm2, 25×25 cm2 and 30×30 cm2 field sizes of Co-60 beam respectively, which were within acceptable limit of ±10%. A noticeable increase in PDDs was observed with increase of the field size at given depth which shows obvious contribution of secondary scattered radiation. Also measured PDDs were well matched with that of published PDDs of most of the authors i.e. ± 2%, but the measured PDDs were moderately matched with that of PDDs for only one author for some field sizes and some depths i.e. ±10%, which need to be rectified by taking more such data.","PeriodicalId":280868,"journal":{"name":"Journal of Physics and Its Applications","volume":"77 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139232396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sasirangan Liquid Waste (SLW) contains heavy metals and chemicals with BOD and COD concentrations exceeding the waste water quality standards in accordance with the Minister of Environment and Forestry Regulation Number P.16 of 2019. The aim of this research is to design and develop a SLW processing system using filter media and composite ceramics made from water chestnut (Eleocharis dulcis). Based on previous research, using the filtration method; filtration and adsorption; filtration, adsorption, sedimentation and ozonization. Filtration method can remove solid particles and sediment from water, so the water appears clearer. The water purification process that involves a filtration method using slow sand filter (SSF), which additional processes are needed either before or after the SSF is carried out. Meanwhile, the use of water chestnut has been carried out by several researchers due to its high active carbon content, namely 50.68%. In this research, we combine several methods including filtration, sedimentation, and ozonization. Water chestnut has a bound carbon content of 84.53% after being activated with an H2SO4 activator, where the largest porosity is found in ceramics with activated charcoal composite materials with variations of the H2SO4 activator. Apart from that, chestnut also has a cellulose content of 35.32% so it has the potential to be effective as a ceramic composite material in sasirangan liquid waste processing filters, especially as an adsorbent. The benefits obtained from the results of this research can be a scientific reference for the use of water chestnut as a filter media and composite ceramic.
{"title":"Development of Sasirangan Liquid Waste Treatment System Using Ozonization Method Using Composite Ceramic Filter Media Based on Water Chestnut (Eleocharis Dulcis)","authors":"Raida Salsabila Khalis, Margareta Margareta, Hasbullah Hasbullah, Eka Suarso, Syifa Fitriana, Ulya Farisa","doi":"10.14710/jpa.v6i1.20582","DOIUrl":"https://doi.org/10.14710/jpa.v6i1.20582","url":null,"abstract":"Sasirangan Liquid Waste (SLW) contains heavy metals and chemicals with BOD and COD concentrations exceeding the waste water quality standards in accordance with the Minister of Environment and Forestry Regulation Number P.16 of 2019. The aim of this research is to design and develop a SLW processing system using filter media and composite ceramics made from water chestnut (Eleocharis dulcis). Based on previous research, using the filtration method; filtration and adsorption; filtration, adsorption, sedimentation and ozonization. Filtration method can remove solid particles and sediment from water, so the water appears clearer. The water purification process that involves a filtration method using slow sand filter (SSF), which additional processes are needed either before or after the SSF is carried out. Meanwhile, the use of water chestnut has been carried out by several researchers due to its high active carbon content, namely 50.68%. In this research, we combine several methods including filtration, sedimentation, and ozonization. Water chestnut has a bound carbon content of 84.53% after being activated with an H2SO4 activator, where the largest porosity is found in ceramics with activated charcoal composite materials with variations of the H2SO4 activator. Apart from that, chestnut also has a cellulose content of 35.32% so it has the potential to be effective as a ceramic composite material in sasirangan liquid waste processing filters, especially as an adsorbent. The benefits obtained from the results of this research can be a scientific reference for the use of water chestnut as a filter media and composite ceramic.","PeriodicalId":280868,"journal":{"name":"Journal of Physics and Its Applications","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139234588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. T. Sugiarto, Nursidik Yulianto, W. P. Tresna, I. Lewa, Isnaeni Isnaeni
Carbon nanodots (Cdots) are a type of semiconductor carbon-based nanomaterial that is gaining popularity due to its excellent characteristics (e.g., biocompatibility, unique optical properties, low cost, eco-friendly, and high stability). In terms of physicochemical properties for an environmentally friendly sensor application, this material also has an excellent ability to detect heavy metal ions in the biosphere. In this study, we proposed a comprehensive optical characterization to examine the sensitivity of the Cdots probe for three heavy metal ions (i.e., Mn, Pb, and Cr ions) and compare the performance. The results of the experiment revealed that each heavy metal ion reacted differently to the physical properties of Cdots. With the addition of Cr, Mn, and Pb metal ions from the original Cdot solution, which is only 1.45 ns, the lifetime of quenched Cdots is 2.55 ns, 3.15 ns, and 2.15 ns, respectively, according to the TRPL experiments. With additional Cr, Mn, and Pb discovered, the intensity of PL dropped by 5.7%, 14.2%, and 21.4%, respectively. Among these various heavy metal ions, Pb ions show the most affected by the quenching effect in Cdots-based photoluminescence, FTIR, and ultraviolet-visible light absorption characterization. Based on the results of three heavy metal ion experiments, this study can be implemented as the heavy metal ion sensor-based luminescence quenching effect of Cdots.
{"title":"Optical Response of Various Heavy Metal Ions-Based Carbon Dots Photoluminescent Quenching Effect","authors":"I. T. Sugiarto, Nursidik Yulianto, W. P. Tresna, I. Lewa, Isnaeni Isnaeni","doi":"10.14710/jpa.v6i1.18755","DOIUrl":"https://doi.org/10.14710/jpa.v6i1.18755","url":null,"abstract":"Carbon nanodots (Cdots) are a type of semiconductor carbon-based nanomaterial that is gaining popularity due to its excellent characteristics (e.g., biocompatibility, unique optical properties, low cost, eco-friendly, and high stability). In terms of physicochemical properties for an environmentally friendly sensor application, this material also has an excellent ability to detect heavy metal ions in the biosphere. In this study, we proposed a comprehensive optical characterization to examine the sensitivity of the Cdots probe for three heavy metal ions (i.e., Mn, Pb, and Cr ions) and compare the performance. The results of the experiment revealed that each heavy metal ion reacted differently to the physical properties of Cdots. With the addition of Cr, Mn, and Pb metal ions from the original Cdot solution, which is only 1.45 ns, the lifetime of quenched Cdots is 2.55 ns, 3.15 ns, and 2.15 ns, respectively, according to the TRPL experiments. With additional Cr, Mn, and Pb discovered, the intensity of PL dropped by 5.7%, 14.2%, and 21.4%, respectively. Among these various heavy metal ions, Pb ions show the most affected by the quenching effect in Cdots-based photoluminescence, FTIR, and ultraviolet-visible light absorption characterization. Based on the results of three heavy metal ion experiments, this study can be implemented as the heavy metal ion sensor-based luminescence quenching effect of Cdots.","PeriodicalId":280868,"journal":{"name":"Journal of Physics and Its Applications","volume":"314 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139278534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Totok Nugroho, Bambang Prajoko, G. Suryawan, Wayan Sukadana
Analysis of minerals and microfabric changes during the burning process of clay in Plambik village, Central Lombok has been carried out using 2 methods: X-Ray Diffraction and Scanning Electron Microscope. A brick of dimension (10 x 20 x 5) mm was prepared which was formed through a gypsum mould. After drying it is burned using an electric furnace with temperatures: 800oC, 1000oC and 1100oC. The results show that using the X-ray diffraction method when burned at 800oC there are quartz minerals with several illite peaks, at 1000oC there is only quartz, the illite peaks disappear while at 1100oC the quartz mineral peaks remain accompanied by the appearance of mullit peaks. Then the effect of the firing temperature on the clay microfabric was analyzed by observing the sample with a Scanning Electron Microscope. This test aims to obtain information about the changes in structure and texture that develop during the combustion process and more specifically on the morphology of the particles and their interaction with the development of the vitrification process and the distribution of the shape and size of the pores. The results showed that before burning, the kaolinite and illite particles were randomly distributed with porous aggregates and the grain size was between 1 – 5 microns. During firing at 800oC some parts have undergone melting and welding phases with the development of secondary porosity. Meanwhile, when burning with a temperature of 1100oC, it appears that the welding and smelting processes that occur are wider and the emergence of mullite crystals from the glass matrix.
龙目岛中部普兰比克村粘土燃烧过程中的矿物和微结构变化分析采用了两种方法：X 射线衍射和扫描电子显微镜。制备的砖块尺寸为（10 x 20 x 5）毫米，由石膏模具成型。干燥后用电炉灼烧，温度分别为 800 摄氏度、1000 摄氏度和 1200 摄氏度：800摄氏度、1000摄氏度和1100摄氏度。结果表明，使用 X 射线衍射法，在 800 摄氏度灼烧时，会出现石英矿物和几个伊利石峰；在 1000 摄氏度灼烧时，只有石英，伊利石峰消失了；而在 1100 摄氏度灼烧时，石英矿物峰仍然存在，同时出现了莫来石峰。然后，用扫描电子显微镜观察样品，分析烧制温度对粘土微织物的影响。该测试旨在获取燃烧过程中结构和质地变化的信息，更具体地说，是颗粒的形态及其与玻璃化过程发展的相互作用，以及孔隙形状和大小的分布。结果表明，在燃烧前，高岭石和伊利石颗粒呈随机分布的多孔聚集体，粒度在 1 - 5 微米之间。在 800 摄氏度的焙烧过程中，一些部分经历了熔化和焊接阶段，并出现了二次孔隙。同时，在 1100 摄氏度的焙烧过程中，出现的焊接和熔融过程似乎更为广泛，玻璃基质中出现了莫来石晶体。
{"title":"Analysis of Clay Mineral Transformation in Plambik Village, Central Lombok Using X-Ray Diffraction and Scanning Electron Microscope Methods","authors":"Totok Nugroho, Bambang Prajoko, G. Suryawan, Wayan Sukadana","doi":"10.14710/jpa.v6i1.19011","DOIUrl":"https://doi.org/10.14710/jpa.v6i1.19011","url":null,"abstract":"Analysis of minerals and microfabric changes during the burning process of clay in Plambik village, Central Lombok has been carried out using 2 methods: X-Ray Diffraction and Scanning Electron Microscope. A brick of dimension (10 x 20 x 5) mm was prepared which was formed through a gypsum mould. After drying it is burned using an electric furnace with temperatures: 800oC, 1000oC and 1100oC. The results show that using the X-ray diffraction method when burned at 800oC there are quartz minerals with several illite peaks, at 1000oC there is only quartz, the illite peaks disappear while at 1100oC the quartz mineral peaks remain accompanied by the appearance of mullit peaks. Then the effect of the firing temperature on the clay microfabric was analyzed by observing the sample with a Scanning Electron Microscope. This test aims to obtain information about the changes in structure and texture that develop during the combustion process and more specifically on the morphology of the particles and their interaction with the development of the vitrification process and the distribution of the shape and size of the pores. The results showed that before burning, the kaolinite and illite particles were randomly distributed with porous aggregates and the grain size was between 1 – 5 microns. During firing at 800oC some parts have undergone melting and welding phases with the development of secondary porosity. Meanwhile, when burning with a temperature of 1100oC, it appears that the welding and smelting processes that occur are wider and the emergence of mullite crystals from the glass matrix.","PeriodicalId":280868,"journal":{"name":"Journal of Physics and Its Applications","volume":"184 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139320521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Weni Antari Putri, R. Riyatun, D. Darmanto, S. Suharyana, Fajar Arianto
Computational simulations of proton therapy with a pencil beam collimator for craniopharyngioma have been done using MCNP6. A pencil beam was radiated towards cube shaped tumor cells in size 1.2 cm, located at a 5.4 cm depth from the surface of the scalp. A 0.1 cm pencil beam was radiated from the left 19.6 cm from the scalp. The cube of tumor cell is divided into the front layer, middle layer, and back layer. Each layer of the tumor cell is divided into 9 cubicles, thus there are 27 cubicles. Using various energy from 108 MeV to 115 MeV and various intensity of energy for each irradiation, it produces the dose for each cubicle in unit MeV/gram per proton. The best isodoses occurred in 5 variations of energy which is 108.2; 111.2; 113.4; 114.7 and 115 MeV. The healthy organ that received the largest dose of the proton is the brain, it is (7.38±0.01)×10-2 MeV/gram per proton, or only 0.412% compared to the tumor cell dose.
{"title":"Optimization of Energy for Proton Therapy with Pencil Beam Collimator Model in Craniopharyngioma Tumor Using MCNP6 Code","authors":"Weni Antari Putri, R. Riyatun, D. Darmanto, S. Suharyana, Fajar Arianto","doi":"10.14710/jpa.v6i1.18100","DOIUrl":"https://doi.org/10.14710/jpa.v6i1.18100","url":null,"abstract":"Computational simulations of proton therapy with a pencil beam collimator for craniopharyngioma have been done using MCNP6. A pencil beam was radiated towards cube shaped tumor cells in size 1.2 cm, located at a 5.4 cm depth from the surface of the scalp. A 0.1 cm pencil beam was radiated from the left 19.6 cm from the scalp. The cube of tumor cell is divided into the front layer, middle layer, and back layer. Each layer of the tumor cell is divided into 9 cubicles, thus there are 27 cubicles. Using various energy from 108 MeV to 115 MeV and various intensity of energy for each irradiation, it produces the dose for each cubicle in unit MeV/gram per proton. The best isodoses occurred in 5 variations of energy which is 108.2; 111.2; 113.4; 114.7 and 115 MeV. The healthy organ that received the largest dose of the proton is the brain, it is (7.38±0.01)×10-2 MeV/gram per proton, or only 0.412% compared to the tumor cell dose.","PeriodicalId":280868,"journal":{"name":"Journal of Physics and Its Applications","volume":"80 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139321549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. C. Verona, A. De los Reyes, H. Bardolaza, E. Estacio
We report on a terahertz quasi-time domain spectroscopy (QTDS) system based on a low-cost continuous wave multimode diode laser. Commercially available low-temperature grown gallium arsenide (LT-GaAs) based photoconductive antennas (PCAs) with spiral and dipole configurations were used as emitter and detector, respectively. Terahertz pulses spaced at approximately 55 ps with a bandwidth of 400 GHz were obtained. Parametric measurements of the terahertz peak-to-peak intensity were performed by varying the injection current and temperature while maintaining incident laser power. The highest peak-to-peak intensity was obtained at 170mA injection current and 20° C temperature settings. The change in the THz peak-to-peak intensity is attributed to the mode hopping characteristics of the device which in turn, is dependent on injection current and temperature.
{"title":"Terahertz Quasi-Time Domain Spectroscopy using a 808nm multimode diode laser","authors":"I. C. Verona, A. De los Reyes, H. Bardolaza, E. Estacio","doi":"10.14710/jpa.v5i2.17945","DOIUrl":"https://doi.org/10.14710/jpa.v5i2.17945","url":null,"abstract":"We report on a terahertz quasi-time domain spectroscopy (QTDS) system based on a low-cost continuous wave multimode diode laser. Commercially available low-temperature grown gallium arsenide (LT-GaAs) based photoconductive antennas (PCAs) with spiral and dipole configurations were used as emitter and detector, respectively. Terahertz pulses spaced at approximately 55 ps with a bandwidth of 400 GHz were obtained. Parametric measurements of the terahertz peak-to-peak intensity were performed by varying the injection current and temperature while maintaining incident laser power. The highest peak-to-peak intensity was obtained at 170mA injection current and 20° C temperature settings. The change in the THz peak-to-peak intensity is attributed to the mode hopping characteristics of the device which in turn, is dependent on injection current and temperature.","PeriodicalId":280868,"journal":{"name":"Journal of Physics and Its Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130978206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Anam, A. Naufal, K. Matsubara, Tosgioh Fujibuchi, G. Dougherty
In computed tomography (CT), the noise is sometimes non-uniform, i.e. the noise magnitude may vary with the gradient level within the image. The purpose of this study was to quantify the noise non-uniformity in CT images using appropriate 1D and 2D computational phantoms, and to validate the effectiveness of the proposed concept in images filtered by the bilateral filter (BF), as an example of a non-linear filter. We first developed 1D and 2D computational phantoms, and Gaussian noises with several noise levels were then added to the phantoms. In addition, to simulate the real form of noise from images obtained in a real CT scanner, a homogeneous water phantom image was used. These noise levels were referred to as ground truth noise (σG). The phantoms were then filtered by the bilateral filter with various pixel value spreads (σ) to produce non-uniform noise. The original gradient phantoms (G) were subtracted from both the noisy phantoms (IN) and the filtered noisy phantoms (IBF), and the magnitudes of the resulting noise for each gradient were computed. The noise-gradient dependency (NGD) curve was used to display the dependency of noise magnitude on image gradient in the non-uniform noise. It is found that for uniform noise, the magnitude of noise was constant for all gradients. However, for non-uniform noise, the measured noise was dependent on the gradient levels and on the strength of the BF for every ground truth noise (σG). It was found that the noise magnitude was large for the large gradients and decreased with the magnitude of the image gradient.
{"title":"A method for quantification of noise non-uniformity in computed tomography images: A computational study","authors":"C. Anam, A. Naufal, K. Matsubara, Tosgioh Fujibuchi, G. Dougherty","doi":"10.14710/jpa.v5i2.17615","DOIUrl":"https://doi.org/10.14710/jpa.v5i2.17615","url":null,"abstract":"In computed tomography (CT), the noise is sometimes non-uniform, i.e. the noise magnitude may vary with the gradient level within the image. The purpose of this study was to quantify the noise non-uniformity in CT images using appropriate 1D and 2D computational phantoms, and to validate the effectiveness of the proposed concept in images filtered by the bilateral filter (BF), as an example of a non-linear filter. We first developed 1D and 2D computational phantoms, and Gaussian noises with several noise levels were then added to the phantoms. In addition, to simulate the real form of noise from images obtained in a real CT scanner, a homogeneous water phantom image was used. These noise levels were referred to as ground truth noise (σG). The phantoms were then filtered by the bilateral filter with various pixel value spreads (σ) to produce non-uniform noise. The original gradient phantoms (G) were subtracted from both the noisy phantoms (IN) and the filtered noisy phantoms (IBF), and the magnitudes of the resulting noise for each gradient were computed. The noise-gradient dependency (NGD) curve was used to display the dependency of noise magnitude on image gradient in the non-uniform noise. It is found that for uniform noise, the magnitude of noise was constant for all gradients. However, for non-uniform noise, the measured noise was dependent on the gradient levels and on the strength of the BF for every ground truth noise (σG). It was found that the noise magnitude was large for the large gradients and decreased with the magnitude of the image gradient.","PeriodicalId":280868,"journal":{"name":"Journal of Physics and Its Applications","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115582224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The light propagation in optical waveguide must be able to maintain low propagation loss, low coupling loss and scattering loss condition, especially in the junction. In this research, a spot size converter is proposed to preserve the lowest coupling loss. This optical converter is composed of a single mode optical fiber (SiO2) including inversed taper. The optical input signal from the optical fiber is launched into photonic integrated circuits and then coupled into the Si-Slab waveguide. Furthermore, linear form with the length dependence has been studied to obtain the optimal position of optical fiber and the chip and analyzed the coupling efficiency of it. The purpose of this research is to procure the optimal form of spot size converter. The simulation result shows the coupling loss of linear form is 0.62 dB and 0.24 dB on TE and TM mode condition respectively. Along with the increase in the taper length, the coupling loss obtained tends to decrease as well. So that, it can be assumed the design of a linear form with 100 μm taper length provides the highest coupling efficie ncy.
{"title":"Coupling Efficiency of a Spot Size Converter for Optical Fiber-Chip Connections","authors":"W. P. Tresna, Dedi Riana, Reza Septiawan","doi":"10.14710/jpa.v5i2.17980","DOIUrl":"https://doi.org/10.14710/jpa.v5i2.17980","url":null,"abstract":"The light propagation in optical waveguide must be able to maintain low propagation loss, low coupling loss and scattering loss condition, especially in the junction. In this research, a spot size converter is proposed to preserve the lowest coupling loss. This optical converter is composed of a single mode optical fiber (SiO2) including inversed taper. The optical input signal from the optical fiber is launched into photonic integrated circuits and then coupled into the Si-Slab waveguide. Furthermore, linear form with the length dependence has been studied to obtain the optimal position of optical fiber and the chip and analyzed the coupling efficiency of it. The purpose of this research is to procure the optimal form of spot size converter. The simulation result shows the coupling loss of linear form is 0.62 dB and 0.24 dB on TE and TM mode condition respectively. Along with the increase in the taper length, the coupling loss obtained tends to decrease as well. So that, it can be assumed the design of a linear form with 100 μm taper length provides the highest coupling efficie ncy.","PeriodicalId":280868,"journal":{"name":"Journal of Physics and Its Applications","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124314123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ruben Cornelius Siagian, L. Alfaris, Aldi Cahya Muhammad, Ukta Indra Nyuswantoro, G. T. Rancak
This research explores the concept of black holes in the physics of general relativity, including its formation and properties. The study focuses on the relationship between the orbital velocity and orbital distance of objects around a black hole, which is measured in units of the speed of light (c) and kiloparsecs (kpc), respectively. Using observational techniques, the study produces a plot showing the relationship between orbital velocity and orbital distance, which follows Kepler's law modified by the Newtonian theory of gravity and general relativity. The study also highlights the effective potential of particles in orbit around a black hole, which combines the effects of kinetic energy and gravitational potential. The effective potential shows the gravitational and relativistic properties of black holes, such as the photon orbit radius, ISCO, and the spin parameter. The resulting plot demonstrates the characteristics of the Milky Way black hole and how its spin parameter and Schwarzschild radius affect the orbital properties of surrounding particles. The study concludes that the closer the orbital distance is to the black hole, the more the orbital velocity increases, and particles with high spin parameters and small Schwarzschild radii are unlikely to escape the black hole's gravity.
{"title":"The Orbital Properties of Black Holes: Exploring the Relationship between Orbital Velocity and Distance","authors":"Ruben Cornelius Siagian, L. Alfaris, Aldi Cahya Muhammad, Ukta Indra Nyuswantoro, G. T. Rancak","doi":"10.14710/jpa.v5i2.17860","DOIUrl":"https://doi.org/10.14710/jpa.v5i2.17860","url":null,"abstract":"This research explores the concept of black holes in the physics of general relativity, including its formation and properties. The study focuses on the relationship between the orbital velocity and orbital distance of objects around a black hole, which is measured in units of the speed of light (c) and kiloparsecs (kpc), respectively. Using observational techniques, the study produces a plot showing the relationship between orbital velocity and orbital distance, which follows Kepler's law modified by the Newtonian theory of gravity and general relativity. The study also highlights the effective potential of particles in orbit around a black hole, which combines the effects of kinetic energy and gravitational potential. The effective potential shows the gravitational and relativistic properties of black holes, such as the photon orbit radius, ISCO, and the spin parameter. The resulting plot demonstrates the characteristics of the Milky Way black hole and how its spin parameter and Schwarzschild radius affect the orbital properties of surrounding particles. The study concludes that the closer the orbital distance is to the black hole, the more the orbital velocity increases, and particles with high spin parameters and small Schwarzschild radii are unlikely to escape the black hole's gravity.","PeriodicalId":280868,"journal":{"name":"Journal of Physics and Its Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134529758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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