16 results
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2. INDIAN INITIATIVES TO ESTABLISH 'WESTERN' ASTRONOMICAL OBSERVATORIES PRIOR TO INDEPENDENCE. 2: COLLEGES AND UNIVERSITIES.
- Author
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Orchiston, Wayne and Kapoor, R. C.
- Subjects
ASTRONOMICAL observatories ,UNIVERSITIES & colleges ,METEOROLOGICAL services ,INDIANS (Asians) ,LOCAL government - Abstract
This paper outlines the efforts to establish Western-style astronomical observatories in India made by colleges and universities over the last century prior to Indian independence in 1947. The focus is therefore on the nineteenth-century emergence of the Presidency College Observatory in Calcutta, St. Xavier's College Observatory in Calcutta, Takhtasinghji Observatory in Poona, and Langat Singh College Observatory in Muzaffarpur. Three of these observatories were established either to aid educated Indians in gaining a realistic knowledge of Western astronomy, or so that India itself could contribute to that body of research knowledge. The fourth observatory, at the Presidency College in Calcutta, was a local government initiative founded primarily to provide a local time service and meteorological data. Unlike the observatories discussed in the first paper in this series, none of the observatories reviewed in this paper was set up primarily to further Britain's colonial ambitions. All were local Indian initiatives, but the critical involvement of Western astronomers or academics at three of the four observatories reveals that a colonial link was still there, albeit as an underlying element. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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3. THE BULLETIN OF THE VILNIUS ASTRONOMICAL OBSERVATORY: A COMPREHENSIVE OVERVIEW (1960-1992).
- Author
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Poškienė, Agnė, Vázquez, Carlos Viscasillas, and Mikolaitis, Šarūnas
- Subjects
ASTRONOMICAL observatories ,WORLD War II ,REINCARNATION ,ASTRONOMERS ,SCIENTIFIC community ,HISTORY of astronomy ,HISTORY of libraries - Abstract
During the eighteenth century professional astronomy started in Lithuania, and over time the first extensive astronomical publications appeared. The tradition of publishing a periodical astronomical Bulletin started in 1921, when Vilnius Astronomical Observatory was led by Polish astronomer Professor Władysław Dziewulski. The outbreak of the Second World War stopped the publication of Bulletins, and 1960 was a crucial year in the rebirth of astronomy in Lithuania. The revitalization of the Bulletin was very important for the Observatory's research and the expansion of the library. During the Soviet occupation, Lithuanian astronomers had limited links abroad. Thus, the Bulletin served as a way to disseminate astronomical research and establish links with international research institutions. This paper examines the history, personalities, contributions and importance to the scientific community of the Bulletin of the Vilnius Astronomical Observatory. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. A deep investigation of the poorly studied open cluster King 18 using CCD VRI, Gaia DR3 and 2MASS.
- Author
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Ahmed, Nasser M., Bendary, R., Samir, R. M., and Elhosseiny, E. G.
- Subjects
STAR clusters ,ASTRONOMICAL observatories ,DATA release ,PARALLAX ,LUMINOSITY ,OPEN clusters of stars - Abstract
In this paper, we re-estimate the astrometric and photometric parameters of the young open star cluster King 18 based on Gaia Data Release 3 (DR3), Two Micron All-sky Survey (2MASS) and VRI CCD observations using the f/4.9 Newtonian focus of 74-inch telescope at Kottamia Astronomical Observatory (KAO) in Egypt. King 18 is a poorly studied open star cluster, for which new results are found in the current study. In order to estimate the membership and determine all the astrophysical parameters of the cluster, we have used data from Gaia DR3 and KAO. The center, cluster radius, radial density distribution, color-magnitude diagrams, distance, age, and reddening of King 18 are calculated. Also, the luminosity and mass functions, the total mass and the relaxation time of the cluster are estimated. The slope value of the mass function (α ) of King 18 is found to be 2.27± 0.17, which is comparable with Salpeter value. Our estimates for the average cluster age and the relaxation time are 224 ± 6.3 and 28.92 Myrs, respectively. This indicates that King 18 is dynamically stable and a relaxed cluster. The cluster distance modulus from Gaia, 2Mass and VRI observations has been determined to be 12.380 ± 1.320, 12.320 ± 0.107 and 12.280 ± 0.290 mag respectively, which corresponds to distances of 2992.26, 2910.72 and 2857.59 pc, respectively. These results are in good agreement within the error. Moreover the color excesses E(V–I), E(J– K s ) and E( G BP – G RP ) are 0.850 ± 0.087, 0.380 ± 0.091 and 0.980 ± 0.130 respectively. Finally, the proper motions ( μ α cos δ , μ δ ), and parallaxes (ϖ ) are - 2.603 ± 0.018 , - 2.106 ± 0.013 and 0.324 ± 0.040, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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5. Timing the stars: Clocks and complexities of precision in eighteenth-century observatories.
- Author
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Gluch, Sibylle
- Subjects
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ASTRONOMICAL observatories , *EIGHTEENTH century , *ORDER picking systems , *PENDULUMS , *TIMEKEEPING - Abstract
In the eighteenth century, the sciences and their applications adopted a new attitude based on quantification and, increasingly, on a notion of precision. Within this process, instruments played a significant role. However, while new devices such as the micrometer, telescope, and pendulum clock embodied a formerly unknown potential of precision, this could only be realized by defining a set of practices regulating their application and control. The paper picks up the case of pendulum clocks used in eighteenth-century observatories in order to show the process of learning in the course of which the pendulum clock first became a precision instrument. By examining the results of an especially developed statistical analysis, conducted to compare the performance of eighteenth-century clocks, it highlights the diversity of conditions, attitudes, and manners of handling that are characteristic for the epoch. In this way, it underlines the necessity of standardization of timekeeping practices rather than exclusively focusing on the technological development of clocks. Ultimately, the paper discusses the role of makers and users in order to show the evolution of a "precision instrument." [ABSTRACT FROM AUTHOR]
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- 2024
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6. Experience deploying an analysis facility for the Rubin Observatory's Legacy Survey of Space and Time (LSST) data.
- Author
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Mainetti, Gabriele, Hernandez, Fabio, Jammes, Fabrice, and Le Boulc'h, Quentin
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ASTRONOMICAL surveys ,ASTRONOMICAL observatories ,HIGH resolution imaging ,ASTRONOMICAL catalogs ,SURVEYS - Abstract
The Vera C. Rubin Observatory is preparing for the execution of the most ambitious astronomical survey ever attempted, the Legacy Survey of Space and Time (LSST). Currently in its final phase of construction in the Andes mountains in Chile and due to start operations in 2025 for 10 years, its 8.4-meter telescope will nightly scan the southern sky and collect images of the entire visible sky every 4 nights using a 3.2 Gigapixel camera, the largest imaging device ever built for astronomy. Automated detection and classification of celestial objects will be performed by sophisticated algorithms on high-resolution images to progressively produce an astronomical catalog eventually composed of 20 billion galaxies and 17 billion stars and their associated physical properties. In this paper, we briefly present the infrastructure deployed at the French Rubin data facility (operated by IN2P3 computing center, CC-IN2P3) to deploy the Rubin Science Platform, a set of web-based services to provide effective and convenient access to LSST data for scientific analysis. We describe the main services of the platform, the components that provide those services and our deployment model. We also present the Kubernetes-based infrastructure we are experimenting with for hosting the LSST astronomical catalog, a petabyte-scale relational database developed for the specific needs of the project. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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7. The high energy X-ray probe (HEX-P): constraining supermassive black hole growth with population spin measurements.
- Author
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Piotrowska, J. M., Garcia, J. A., Walton, D. J., Beckmann, R. S., Stern, D., Ballantyne, D. R., Wilkins, D. R., Bianchi, S., Boorman, P. G., Buchner, J., Chen, C.-T., Coppi, P., Dauser, T., Fabian, A. C., Kammoun, E., Madsen, K., Mallick, L., Matt, G., Matzeu, G., and Nardini, E.
- Subjects
BLACK holes ,X-rays ,X-ray spectra ,ASTRONOMICAL observatories ,SUPERMASSIVE black holes - Abstract
Constraining the primary growth channel of supermassive black holes (SMBHs) remains one the most actively debated questions in the context of cosmological structure formation. Owing to the expected connection between SMBH spin parameter evolution and the accretion and merger history of individual black holes, population spin measurements offer a rare observational window into the cosmic growth of SMBHs. As of today, the most common method for estimating SMBH spin relies on modeling the relativistically broaden atomic profiles in the reflection spectrum observed in X-rays. In this paper, we study the observational requirements needed to confidently distinguish between the primary SMBH growth channels based on their distinct spin-mass distributions predicted by the Horizon-AGN cosmological simulation. Indoing so, we characterize outstanding limitations associated with the existing measurements and discuss the landscape of future observational campaigns which could be planned and executed with future X-ray observatories. We focus our attention on the High-Energy X-ray Probe (HEX-P), a proposed probe-class mission designed to serve the high- energy community in the 2030s. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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8. Nonlinear Characteristics of Radio Variability in Quasar 3C 446.
- Author
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Jie, Tang
- Subjects
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HILBERT-Huang transform , *TIME series analysis , *COLLEGE radio stations , *RADIO astronomy , *ASTRONOMICAL observatories - Abstract
Quasars are characterized by violent and large amplitude variability in all the observation wavelengths, and the analysis of optical variability is useful for developing theoretical models. Long-term optical variability data of quasar 3C 446 were collected from the University of Michigan Radio Astronomy Observatory database in the 4.8, 8.0, and 14.5 GHz radio bands from 1976 to 2012. Due to the complexity of the variability data, it's hard to study by the linear time series analysis methods. For learning more about non-linear characteristics of the temporal evolution of quasar variability, the Ensemble Empirical Mode Decomposition and nonlinear analysis are used to analyse chaotic dynamics, fractal properties, and periodicity. This paper focuses on whether there is a significant difference between the periodic and non-linear properties of the quasar variability before and after the removal of the periodic or chaotic components. It turns out that the variability of quasar 3C 446 in the radio bands consists of periodic, trend, and chaotic components, and the periodic and trend components are dominant. The periods of the variability after removing the chaotic and trend components are exactly the same as the periods of the original variability data, but the chaotic and fractal characteristics of the two are significantly different. The saturated correlation dimension indicates that the reconstruction of the dynamical system requires more independent parameters than the original optical variables after the removal of the periodic and trend components. The Kolmogorov entropy indicates that the loss of information is greater for the former than the latter, and the system is more chaotic and more complex. The Hurst value indicates that the self-similarity and long-range correlation are slightly stronger for the latter than the former. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. H i galaxy signatures in the SARAO MeerKAT galactic plane survey − III. Unveiling the obscured part of the Vela Supercluster.
- Author
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Rajohnson, Sambatriniaina H A, Kraan-Korteweg, Renée C, Chen, Hao, Frank, Bradley S, Steyn, Nadia, Kurapati, Sushma, Pisano, D J, Staveley-Smith, Lister, Serra, Paolo, Goedhart, Sharmila, and Camilo, Fernando
- Subjects
- *
MEERKAT , *GALAXIES , *RADIO frequency , *ASTRONOMICAL observatories , *LARGE scale structure (Astronomy) , *RADIO astronomy - Abstract
We conducted a search for |$\textrm {H}\, \scriptstyle \mathrm{I}$| emission of the gas-rich galaxies in the Vela region (260° ≤ ℓ ≤ 290°, −2° ≤ b ≤ 1°) to explore the Vela Supercluster (VSCL) at V hel ∼ 18 000 |$\rm km\, s^{-1}$| , largely obscured by Galactic dust. Within the mostly Radio Frequency Interference-free band (250 < V hel < 25 000 |$\rm km\, s^{-1}$|) of MeerKAT, the analysis focuses on 157 hexagonally distributed pointings extracted from the South African Radio Astronomy Observatory MeerKAT Galactic Plane Survey located in the Vela region (Vela−SMGPS). These were combined into 10 contiguous mosaics, covering an ∼90 square degrees area. Among the 843 |$\textrm {H}\, \scriptstyle \mathrm{I}$| detected sources, 39 were previously discovered in the H i Parkes Zone of Avoidance survey (V hel < 12 000 |$\rm km\, s^{-1}$| ; rms ∼ 6 |$\rm mJy\, beam^{-1}$|). With the improved rms level of the Vela−SMGPS, i.e. 0.29–0.56 |$\rm mJy\, beam^{-1}$| , our study unveils nearly 12 times more detections (471 candidates) in that same velocity range. We furthermore could identify 187 galaxy candidates with an |$\textrm {H}\, \scriptstyle \mathrm{I}$| mass limit reaching |$\log (M_{\rm HI}/\rm {\rm M}_{\odot }) = 9.44$| in the VSCL velocity range V hel ∼ 19 500 ± 3500 |$\rm km\, s^{-1}$|. We find indications of two wall-like overdensities that confirm the original suspicion that these walls intersect at low latitudes around longitudes of ℓ ∼ 272°–278°. We also find a strong signature most likely associated with the Hydra/Antlia extension and evidence of a previously unknown narrow filament at V hel ∼ 12 000 |$\rm km\, s^{-1}$|. This paper demonstrates the efficiency of systematic |$\textrm {H}\, \scriptstyle \mathrm{I}$| surveys with the Square Kilometre Array (SKA) precursor MeerKAT, even in the most obscured part of the Zone of Avoidance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
10. A bibliometric study of research output of ISRO's space science and exploration missions.
- Author
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Ummer, Rehana and Rajgoli, Iqbalahmad U.
- Subjects
- *
SPACE sciences , *SPACE exploration , *BIBLIOMETRICS , *INFORMATION resources , *ASTRONOMICAL observatories - Abstract
Chandrayaan-1 and Chandrayaan-2, the Indian Mars Orbiter Mission (MOM), and a multi-wavelength astronomical observatory (AstroSat) are the missions launched by the Indian Space Research Organisation (ISRO) under the broader category of space science and exploration. The results generated from the periodically released data from these missions, are published in the form of journal articles, conference papers, The Astronomer's Telegrams, GRB Coordinates Network circulars, etc. The goal of this study is a bibliometric analysis of 592 journal articles on ISRO's four space science and exploration missions which were published between 2002 and 2021 (20 years). The Web of Science Core collection database and Google Scholar are used to retrieve the data needed for the study. Bibliometric indicators like mission-wise distribution of articles; year-wise distribution of articles, relative growth rate and doubling time of publications; prolific authors; leading institutions; international collaboration; highly ranked journals; highly cited articles and keyword occurrences were considered for analysis. The doubling time of publications of those missions which yielded the highest number of articles were separately calculated using an exponential equation and built in algorithms in Python. Advanced data visualization tool such as VosViewer was used for generating the network maps. The bibliometric analysis revealed the usage of mission output data not only by ISRO scientists but also by academia, research labs, etc. Overall, the study can be considered as a comprehensive reference source for information on research trends related to the four Indian space science and exploration missions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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11. Sustainable astronomy: A comparative life cycle assessment of off-grid hybrid energy systems to supply large telescopes
- Author
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Viole, Isabelle, Shen, Li, Camargo, Luis Ramirez, Zeyringer, Marianne, and Sartori, Sabrina
- Published
- 2024
- Full Text
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12. Overview of the distributed image processing infrastructure to produce the Legacy Survey of Space and Time.
- Author
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Hernandez, Fabio, Beckett, George, Clark, Peter, Doidge, Matt, Jenness, Tim, Karavakis, Edward, Le Boulc'h, Quentin, Love, Peter, Mainetti, Gabriele, Noble, Timothy, White, Brandon, and Yang, Wei
- Subjects
IMAGE processing ,SERVER farms (Computer network management) ,ALGORITHMS ,ASTRONOMICAL observatories ,ELECTRONIC data processing - Abstract
The Vera C. Rubin Observatory is preparing to execute the most ambitious astronomical survey ever attempted, the Legacy Survey of Space and Time (LSST). Currently the final phase of construction is under way in the Chilean Andes, with the Observatory's ten-year science mission scheduled to begin in 2025. Rubin's 8.4-meter telescope will nightly scan the southern hemisphere collecting imagery in the wavelength range 320–1050 nm covering the entire observable sky every 4 nights using a 3.2 gigapixel camera, the largest imaging device ever built for astronomy. Automated detection and classification of celestial objects will be performed by sophisticated algorithms on high-resolution images to progressively produce an astronomical catalog eventually composed of 20 billion galaxies and 17 billion stars and their associated physical properties. In this article we present an overview of the system currently being constructed to perform data distribution as well as the annual campaigns which reprocess the entire image dataset collected since the beginning of the survey. These processing campaigns will utilize computing and storage resources provided by three Rubin data facilities (one in the US and two in Europe). Each year a Data Release will be produced and disseminated to science collaborations for use in studies comprising four main science pillars: probing dark matter and dark energy, taking inventory of solar system objects, exploring the transient optical sky and mapping the Milky Way. Also presented is the method by which we leverage some of the common tools and best practices used for management of large-scale distributed data processing projects in the high energy physics and astronomy communities. We also demonstrate how these tools and practices are utilized within the Rubin project in order to overcome the specific challenges faced by the Observatory. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
13. The case for an all-sky millimetre survey at subarcminute resolution.
- Author
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Désert, François-Xavier, Calvo, Martino, Catalano, Andrea, Leclercq, Samuel, Macias-Perez, Juan, Mayet, Frédéric, Monfardini, Alessandro, Perotto, Laurence, and Ponthieu, Nicolas
- Subjects
COSMIC background radiation ,MILLIMETER waves ,ASTRONOMICAL observatories ,UNIVERSE - Abstract
There are several new projects to survey the sky with millimetre eyes, the biggest being Simons Observatory and CMB-S4, in the Southern Hemisphere. The NIKA2 collaboration has acquired sufficient knowledge to build a large focal plane KID camera for a 15 m antenna. This would allow covering the whole Northern Hemisphere in five years at subarcminute resolution and with milliJansky point-source sensitivity. We describe the main scientific drivers for such a project: the SZ sky, the high-redshift millimetre Universe and the interstellar medium in our Galaxy and the nearby galaxies. We also show briefly the main difficulties (scientific, organisational, technical and financial). [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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14. The ASTRI Mini-Array: A New Pathfinder for Imaging Cherenkov Telescope Arrays.
- Author
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Scuderi, Salvatore
- Subjects
TECHNOLOGICAL innovations ,ASTRONOMICAL observatories ,TELESCOPES ,OBSERVATORIES - Abstract
The ASTRI Mini-Array is an Istituto Nazionale di Astrofisica (INAF) project to build and operate an array of nine Imaging Atmospheric Cherenkov Telescopes (IACTs) at the Teide Astronomical Observatory of the Instituto de Astrofisica de Canarias in Tenerife (Spain) based on a host agreement with INAF and, as such, it will be the largest IACT array until the Cherenkov Telescope Array Observatory starts operations. Implementing the ASTRI Mini-Array poses several challenges from technical, logistic, and management points of view. Starting from the description of the innovative technologies adopted to build the telescopes, we will discuss the solutions adopted to overcome these challenges, making the ASTRI Mini-Array a great instrument to perform deep observations of the galactic and extra-galactic sky at very high energies. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. Polarimetric observations of blazars at Belogradchik Observatory.
- Author
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Bachev, Rumen
- Subjects
BL Lacertae objects ,POLARIMETRIC remote sensing ,ASTRONOMICAL observatories ,SYNCHROTRON radiation ,RADIO jets (Astrophysics) - Abstract
With the use of a simple polarimeter, recently introduced at the 60cm telescope of Belogradchik observatory, we obtained our first results on blazar polarimetric variability. Practically all objects we studied showed significant and variable linear polarization as expected from synchrotron emission in a relativistic jet. Observational methods used and some of the first results are presented and discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
16. Estimation of Astronomical Seeing with Neural Networks at the Maidanak Observatory.
- Author
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Shikhovtsev, Artem Y., Kiselev, Alexander V., Kovadlo, Pavel G., Kopylov, Evgeniy A., Kirichenko, Kirill E., Ehgamberdiev, Shuhrat A., and Tillayev, Yusufjon A.
- Subjects
ARTIFICIAL neural networks ,OBSERVATORIES ,WHIRLWINDS ,ASTRONOMICAL observatories ,DATABASES - Abstract
In the present article, we study the possibilities of machine learning for the estimation of seeing at the Maidanak Astronomical Observatory (38 ∘ 40 ′ 24 ″ N, 66 ∘ 53 ′ 47 ″ E) using only Era-5 reanalysis data. Seeing is usually associated with the integral of the turbulence strength C n 2 (z) over the height z. Based on the seeing measurements accumulated over 13 years, we created ensemble models of multi-layer neural networks under the machine learning framework, including training and validation. For the first time in the world, we have simulated optical turbulence (seeing variations) during night-time with deep neural networks trained on a 13-year database of astronomical seeing. A set of neural networks for simulations of night-time seeing variations was obtained. For these neural networks, the linear correlation coefficient ranges from 0.48 to 0.68. We show that modeled seeing with neural networks is well-described through meteorological parameters, which include wind-speed components, air temperature, humidity, and turbulent surface stresses. One of the fundamental new results is that the structure of small-scale (optical) turbulence over the Maidanak Astronomical Observatory does not depend or depends negligibly on the large-scale vortex component of atmospheric flows. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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