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Erratum: “Effect of dimensionality on the continuum percolation of overlapping hyperspheres and hypercubes. II. Simulation results and analyses” [J. Chem. Phys. 137, 074106 (2012)]

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The Journal of Chemical physics 2014年第15期141卷

作者： S. Torquato Y. Jiao 1Department of Chemistry Department of Physics Princeton Center for Theoretical Science and Program in Applied and Computational Mathematics Princeton University Princeton New Jersey 08544 USA 2Princeton Institute for the Science and Technology of Materials Princeton University Princeton New Jersey 08544 USA

In Table I and the caption of Fig. 8 of Ref. 1, the numerical value of the percolation threshold ηc of three-dimensional overlapping spheres as determined via t

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Rethinking CO antibiosignatures in the search for life beyond the solar system

arXiv

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arXiv 2019年

作者： Schwieterman, Edward W. Reinhard, Christopher T. Olson, Stephanie L. Ozaki, Kazumi Harman, Chester E. Hong, Peng K. Lyons, Timothy W. Department of Earth Sciences University of California RiversideCA United States NASA Postdoctoral Program Universities Space Research Association ColumbiaMD United States NASA Astrobiology Institute Alternative Earths & Virtual Planetary Laboratory Teams United States Blue Marble Space Institute of Science SeattleWA United States School of Earth and Atmospheric Sciences Georgia Institute of Technology AtlantaGA United States Department of Geophysical Sciences University of Chicago ChicagoIL United States Department of Environmental Science Toho University Tokyo Japan NASA Goddard Institute for Space Studies New YorkNY United States Department of Applied Mathematics and Applied Physics Columbia University New YorkNY United States Planetary Exploration Research Center Chiba Institute of Technology 2-17-1 Tsudanuma Narashino Chiba275-0016 Japan

Some atmospheric gases have been proposed as counter indicators to the presence of life on an exoplanet if remotely detectable at sufficient abundance (i.e., antibiosignatures), informing the search for biosignatures and potentially fingerprinting uninhabited habitats. However, the quantitative extent to which putative antibiosignatures could exist in the atmospheres of inhabited planets is not well understood. The most commonly referenced potential antibiosignature is CO, because it represents a source of free energy and reduced carbon that is readily exploited by life on Earth and is thus often assumed to accumulate only in the absence of life. Yet, biospheres actively produce CO through biomass burning, photooxidation processes, and release of gases that are photochemically converted into CO in the atmosphere. We demonstrate with a 1D ecosphere-atmosphere model that reducing biospheres can maintain CO levels of ~100 ppmv even at low H2fluxes due to the impact of hybrid photosynthetic ecosystems. Additionally, we show that photochemistry around M dwarf stars is particularly favorable for the buildup of CO, with plausible concentrations for inhabited, oxygen-rich planets extending from hundreds of ppm to several percent. Since CH4buildup is also favored on these worlds, and because O2and O3are likely not detectable with the James Webb Space Telescope, the presence of high CO (>100 ppmv) may discriminate between oxygen-rich and reducing biospheres with near-future transmission observations. These results suggest that spectroscopic detection of CO can be compatible with the presence of life and that a comprehensive contextual assessment is required to validate the significance of potential antibiosignatures. Copyright © 2019, The Authors. All rights reserved.

关键词： Free energy

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A Robust Light-Curve Diagnostic for Electron-Capture Supernovae and Low-Mass Fe-Core-Collapse Supernovae

arXiv

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arXiv 2024年

作者： Sato, Masato Tominaga, Nozomu Blinnikov, Sergei I. Potashov, Marat Sh. Moriya, Takashi J. Hiramatsu, Daichi Astronomical Science Program Graduate Institute for Advanced Studies SOKENDAI 2-21-1 Osawa Tokyo Mitaka181-8588 Japan National Astronomical Observatory of Japan National Institutes of Natural Sciences 2-21-1 Osawa Tokyo Mitaka181-8588 Japan Department of Physics Faculty of Science and Engineering Konan University 8-9-1 Okamoto Hyogo Kobe658-8501 Japan NRC Kurchatov Institute Moscow123182 Russia Moscow127055 Russia Keldysh Institute of Applied Mathematics RAS 4 Miusskaya Square Moscow125047 Russia School of Physics and Astronomy Monash University ClaytonVIC3800 Australia Center for Astrophysics | Harvard & Smithsonian 60 Garden Street CambridgeMA02138-1516 United States The NSF AI Institute for Artificial Intelligence and Fundamental Interactions United States

Core-collapse supernovae (CCSNe) are the terminal explosions of massive stars. While most massive stars explode as iron-core-collapse supernovae (FeCCSNe), slightly less massive stars explode as electron-capture supernovae (ECSNe), shaping the low-mass end of CCSNe. ECSNe was proposed ∼ 40 years ago and first-principles simulations also predict their successful explosions. Observational identification and investigation of ECSNe are important for the completion of stellar evolution theory. To date, only one promising candidate has been proposed, SN 2018zd, other than the historical progenitor of the Crab Nebula, SN 1054. We present representative synthetic light curves of low-mass FeCCSNe and ECSNe exploding with energies in circumstellar media (CSM) estimated with theoretically or observationally plausible methods. The plateaus of the ECSNe are shorter, brighter, and bluer than those of the FeCCSNe. To investigate the robustness of their intrinsic differences, we adopted various explosion energies and CSM. Although they may have similar bolometric light-curve plateaus, ECSNe are bluer than FeCCSNe in the absence of strong CSM interaction, illustrating that multicolor observations are essential to identify ECSNe. This provides a robust indicator of ECSNe because the bluer plateaus stem from the low-density envelopes of their super-asymptotic-giant-branch progenitors. Furthermore, we propose a distance-independent method to identify ECSNe: (g − r)tPT/2 PT − 0.4, i.e., blue g − r at the middle of the plateau (g − r)tPT/2, where tPT is the transition epoch from plateau to tail. Using this method, we identified SN 2018zd as an ECSN, which we believe to be the first ECSN identified with modern observing techniques. © 2024, CC BY.

关键词： Supernovae

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Implementation of a selective mean filter algorithm to reduce noise in computed radiography images

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AIP Conference Proceedings 2021年第1期2346卷

作者： J. H. Saragih C. Anam W. S. Budi T. I. Simarmata G. Dougherty 1Postgraduate Program Department of Physics Faculty of Sciences and Mathematics Diponegoro University Jl. Prof. Soedarto SH Tembalang Semarang 50275 Central Java Indonesia 2Department of Physics Faculty of Sciences and Mathematics Diponegoro University Jl. Prof. Soedarto SH Tembalang Semarang 50275 Central Java Indonesia 3Department of Radiology Premier Jatinegara Hospital Jl. Jatinegara Timur No. 85-87 Jatinegara Kota Jakarta Timur 13310 DKI Jakarta Indonesia 4Department of Applied Physics and Medical Imaging California State University Channel Islands Camarillo CA 93012 USA

This study implements a selective mean filter (SMF) and determines its effectiveness on computed radiography (CR) images. A phantom of the Kualitas Citra Imajing (KUCING) was used. The effectiveness of the SMF was compared to the adaptive mean filter (AMF). The assessment of image quality was based on several parameters, such as the peak signal to noise ratio (PSNR), mean squared error (MSE), structural similarity index (SSIM), contrast consistency (CV), contrast linearity (CL), and modulation transfer function (MTF). The results show that the PSNR value generated by the SMF is higher than with the AMF. The MSE value generated by the SMF algorithm is lower than AMF. The SSIM values showed that SMF algorithm produces a better image similarity between the original image and the filtered image compared to the AMF algorithm. In consistency and linearity, the AMF leads to significant changes from the original image, while the SMF image is closer to the original image. The 10% MTF generated by the SMF is the same as the original image, while AMF produces a significant decrease in the 10% MTF. The SMF took 17.9 ± 0.7 seconds for denoising one CR image, while AMF took 519 ± 5 seconds. SMF decreases image noise without a significant effect on the spatial resolution of the image. SMF filtering is superior to AMF filtering in terms of spatial resolution and a shorter computational time.

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Subsurface characterization of Diwak-Derekan geothermal field by HVSR analysis method based on mictrotremor data

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AIP Conference Proceedings 2020年第1期2296卷

作者： Vithya Arintalofa Gatot Yuliyanto Udi Harmoko 1Master Program of Energy School of Postgraduate Studies Diponegoro University Jl. Imam Bard}o SH No.5 Pleburan Semarang 50241 Indonesia 2Department of Physics Faculty of Science and Mathematics Diponegoro University Jl. Prof. Soedharto SH Tembalang Semarang 50275 Semarang Indonesia

The research aims to analyze the subsurface structures that are manifested in geothermal represented by using the Horizontal to Vertical Spectral Ratio (HVSR) method. The data is obtained by microtremor recording, which obtains the dominant frequency value and amplification factor that will give the value of the wave velocity P (Vp) and the wave velocity S (Vs). The results of the study at 52 measurement points were processed using Geopsy and Surfer 13. The results of microtremor data processing using the HVSR method obtained the distribution of dominant frequency values around 0.08 to 9.29 Hz, the distribution of amplification factor values around 0.03 to 7.07, the distribution of Vp values around 390 m/s to 4993 m/s and the distribution of Vs values around 190 m/s to 3054 m/s. Manifestation area of Diwak- Derekan is located on the weak zone, based on the subsurface structural analysis, a possibility of normal fault is also identified, it causes manifestation of hot water springs on the surface. The Poisson's Ratio shows subsurface lithology mostly in the form of sandy loam, and a small portion of silt and saturated clay. The analysis of Poisson's Ratio shows the geothermal manifestation area is possibly a geothermal system that the fluid type is dominated by vapor/steam. The result explains that microtremor analysis by HVSR method can be utilized to subsurface interpretation for characterization purpose of the study area.

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Physical model of discontinuity response in landslide application using geometry normalized electromagnetic system (GNES)

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AIP Conference Proceedings 2020年第1期2221卷

作者： Muhammad Syukri Surbakti Bukhari Nazli Ismail Nasrullah Idris Muhammad Isa Elin Yusibani Zakaria Muhammad Nurman Mohd Zubir Mat Jafri 1Department of Physics Faculty of Mathematics and Natural Sciences Universitas Syiah Kuala Jln. SyechAbdul Ra’uf No. 3 Darussalam 23111 Banda Aceh Aceh Indonesia 2Doctorate Program of Mathematics and Applied Science (DMAS) Postgraduate Program Universitas Syiah Kuala Banda Aceh 23111 Indonesia 3SMAN 2 Binjai Jalan Padang No. 8 Binjai 20722 Indonesia 4School of Physics UniversitiSains Malaysia Minden 11800 Penang Malaysia

The discontinuity in a fractured land in landslide application could be represented by the metal defects in the physical modeling that will usually reduce the mass of the metal. The scale factor n is important for interpreting the field data using the physical model data. In this physical modeling (n = 100), the anomaly targets are aluminum plates and aluminum plates with the discontinuities. It is assumed the nonconductive environment. In the free-air condition which has zero conductivity is become representative of this environment. In the zero conductivity, the secondary field from the medium is not presence. In this condition, there are no phase differences between transmitted electromagnetic fields and that was received by the receiver. The discontinuity in this term is any treatment or defect that causes disruption or leads to a reduction in response triggered by the eddy currents. The discontinuities used on the thin plates and flaws will interrupt or reduce the eddy current flow on the plate, thereby reducing the induced voltage on the receiving coil and increasing its effective impedance. This is the basis of eddy current measurement. The electromagnetic field response to a metal that has discontinuities will change the eddy current portion. The eddy current that changes, therefore, will change the second field so that the percent response (% Response) of the receiver in the Geometry Normalized Electromagnetic System (GNES) instrument will also change.

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Erratum: “Stabilization of orthorhombic phase in single-crystal ZnSnN2 films” [AIP Advances 6, 075019 (2016)]

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AIP Advances 2018年第12期8卷

作者： Nancy Senabulya Nathaniel Feldberg Robert. A. Makin Yongsoo Yang Guangsha Shi Christina M. Jones Emmanouil Kioupakis James Mathis Roy Clarke Steven M. Durbin 1Applied Physics Program University of Michigan Ann Arbor Michigan 48109 USA 2Department of Physics University at Buffalo Buffalo New York 14260 USA 3Department of Electrical and Computer Engineering Western Michigan University Kalamazoo Michigan 49008-5329 USA 4Department of Physics University of Michigan Ann Arbor Michigan 48109 USA 5Department of Materials Science and Engineering University of Michigan Ann Arbor Michigan 48109 USA

Both these corrections are typographical errors that do not affect the validity of results in the original article.

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EEG channels reduction using PCA to increase XGBoost’s accuracy for stroke detection

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AIP Conference Proceedings 2017年第1期1862卷

作者： N. Fitriah S. K. Wijaya M. I. Fanany C. Badri M. Rezal 1Biomedical Engineering Study Program Universitas Indonesia Jl. Salemba Raya No. 4 Jakarta 10430 DKI Jakarta Indonesia 2Department of Physics Faculty of Mathematics and Natural Sciences (FMIPA) Universitas Indonesia Depok 16424 Indonesia 3Faculty of Computer Science Universitas Indonesia Depok 16424 Indonesia

In Indonesia, based on the result of Basic Health Research 2013, the number of stroke patients had increased from 8.3 ‰ (2007) to 12.1 ‰ (2013). These days, some researchers are using electroencephalography (EEG) result as another option to detect the stroke disease besides CT Scan image as the gold standard. A previous study on the data of stroke and healthy patients in National Brain Center Hospital (RS PON) used Brain Symmetry Index (BSI), Delta-Alpha Ratio (DAR), and Delta-Theta-Alpha-Beta Ratio (DTABR) as the features for classification by an Extreme Learning Machine (ELM). The study got 85% accuracy with sensitivity above 86 % for acute ischemic stroke detection. Using EEG data means dealing with many data dimensions, and it can reduce the accuracy of classifier (the curse of dimensionality). Principal Component Analysis (PCA) could reduce dimensionality and computation cost without decreasing classification accuracy. XGBoost, as the scalable tree boosting classifier, can solve real-world scale problems (Higgs Boson and Allstate dataset) with using a minimal amount of resources. This paper reuses the same data from RS PON and features from previous research, preprocessed with PCA and classified with XGBoost, to increase the accuracy with fewer electrodes. The specific fewer electrodes improved the accuracy of stroke detection. Our future work will examine the other algorithm besides PCA to get higher accuracy with less number of channels.

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Physical properties of Gd3+ ion doped fluorotellurite glass and their radiation shielding parameter

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AIP Conference Proceedings 2023年第1期2540卷

作者： L. Yuliantini M. B. Sari M. Djamal K. Boonin P. Yasaka J. Kaewkhao 1Department of Physics Faculty of Military Mathematics and Natural Sciences The Republic of Indonesia Defense University Bogor 16810 Indonesia 2Department of Physics Faculty of Mathematics and Natural Sciences Bandung Institute of Technology Bandung 46132 Indonesia 3Center for Underground Physics Institute for Basic Science 55 Expo-ro Yuseong-gu Daejeon 34126 Republic of Korea 4Physics Study Program Department of Science Sumatera Institute of Technology Lampung 35365 Indonesia 5Center of Excellence in Glass Technology and Materials Science (CEGM) Nakhon Pathom Rajabhat University Nakhon Pathom 73000 Thailand 6Physics Program Faculty of Science and Technology Nakhon Pathom Rajabhat University Nakhon Pathom 73000 Thailand

Currently, the utilization of X-ray and Gamma-ray have been widely increased due to their applications such as in the medical (Roentgen, PET, MRI, etc.), industrial and scientific fields. As we know, they have high energy and exposure to X-ray and Gamma-ray will be dangerous for the human body. People who work in the radiation field need protection. In the present work, we have developed glass material for radiation protection. The glass composition was (90-x)TeO2+10ZnF2+xGd2O3 where x is 2, 4, 6, 8, and 10 mol%. The glasses were fabricated using the conventional melt and quenching technique. The mixed material was melted at T=1050 0C for 1.5 hours and annealed at T=500 0C for 1.5 hours. Afterwards, they can be treated at room temperature for characterizations including physical, optical, and the simulation of radiation shielding properties. The physical properties of glass consist of density and molar volume. The glass density laid between 4.15 to 4.75 g/cm3 where the glass density increased by increasing Gd2O3 concentration in the glass system. Meanwhile, the molar volume of glass was found between 36.69 to 38.07 cm3/mol where the molar volume decreased with increasing of Gd2O3 content. The radiation shielding parameter such as mass attenuation coefficient (μm) and effective atomic number (Zeff) have been simulated using Photon Shielding and Dosimetry (PSD) software that is available at https://***/PSD. The response of glass material in the energy range of 0.28 – 0.66 MeV has been studied to understand their radiation shielding properties.

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The EB-correlation in Resolved Polarized Images: Connections to Astrophysics of Black Holes

arXiv

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arXiv 2023年

作者： Emami, Razieh Doeleman, Sheperd S. Wielgus, MacIek Chang, Dominic Chatterjee, Koushik Smith, Randall Liska, Matthew Steiner, James F. Ricarte, Angelo Narayan, Ramesh Tremblay, Grant Finkbeiner, Douglas Hernquist, Lars Chan, Chi-Kwan Blackburn, Lindy Prather, Ben S. Tiede, Paul Broderick, Avery E. Vogelsberger, Mark Alcock, Charles Roelofs, Freek Center for Astrophysics Harvard & Smithsonian 60 Garden Street CambridgeMA02138 United States Black Hole Initiative Harvard University 20 Garden Street CambridgeMA02138 United States Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 BonnD-53121 Germany Steward Observatory Department of Astronomy University of Arizona 933 N. Cherry Ave. TucsonAZ85721 United States Data Science Institute University of Arizona 1230 N. Cherry Ave. TucsonAZ85721 United States Program in Applied Mathematics University of Arizona 617 N. Santa Rita TucsonAZ85721 United States CCS-2 Los Alamos National Laboratory P.O. Box 1663 Los AlamosNM87545 United States Perimeter Institute for Theoretical Physics 31 Caroline Street North WaterlooONN2L 2Y5 Canada Department of Physics and Astronomy University of Waterloo 200 University Avenue West WaterlooONN2L 3G1 Canada Department of Physics Kavli Institute for Astrophysics and Space Research Massachusetts Institute of Technology CambridgeMA02139 United States

We present an in-depth analysis of a newly proposed correlation function in visibility space, between the E and B modes of the linear polarization, hereafter the EB-correlation, for a set of time-averaged GRMHD simulations compared with the phase map from different semi-analytic models as well as the Event Horizon Telescope (EHT) 2017 data for M87∗source. We demonstrate that the phase map of the time-averaged EB-correlation contains novel information that might be linked to the BH spin, accretion state and the electron temperature. A detailed comparison with a semi-analytic approach with different azimuthal expansion modes shows that to recover the morphology of the real/imaginary part of the correlation function and its phase, we require higher orders of these azimuthal modes. To extract the phase features, we propose to use the Zernike polynomial reconstruction developing an empirical metric to break degeneracies between models with different BH spins that are qualitatively similar. We use a set of different geometrical ring models with various magnetic and velocity field morphologies and show that both the image space and visibility based EB-correlation morphologies in MAD simulations can be explained with simple fluid and magnetic field geometries as used in ring models. SANEs by contrast are harder to model, demonstrating that the simple fluid and magnetic field geometries of ring models are not sufficient to describe them owing to higher Faraday Rotation depths. A qualitative comparison with the EHT data demonstrates that some of the features in the phase of EB-correlation might be well explained by the current models for BH spins as well as electron temperatures, while others may require a larger theoretical surveys. © 2023, CC BY.

关键词： Polarization

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