IOSR-JAP   Volume-17 ~ Issue-4 ~ Jul. – Aug. 2025

ABSTRACT: The uranium-238 radioactive series is a well-known multi-step decay chain involving multiple alpha and beta-negative decays, ultimately resulting in the stable lead-206 isotope. In this work, we use computational simulations with Monte Carlo method to analyze the stochastic timing of decay events and to evaluate hypothetical decay pathways. Initially, by considering only mass and charge conservation, we identify 3,003 theoretical decay chains. However, many of these chains are unphysical due to energy constraints and nuclear stability. By incorporating additional nuclear physics principles, such as decay energy and nuclear shell stability, we confirm that only the well-established uranium-238 decay series is physically possible. This approach demonstrates a practical application of computational techniques to analyze nuclear decay chains.

Keywords: Uranium-238; Radioactive series; Nuclear decay; Simulation; Monte Carlo method.

[1]. R. Cayrel, V. Hill, T.C. Beers, Et Al. Measurement Of Stellar Age From Uranium Decay. Nature 2001; 409: 691-692.
[2]. V. Michel, C.C. Shen, J. Woodhead, Et Al. New Dating Evidence Of The Early Presence Of Hominins In Southern Europe. Scientific Reports 2017; 7: 10074.
[3]. N. Moromoto, Y. Kawai, K. Terada, Et Al. Uranium–Lead Systematics Of Lunar Basaltic Meteorite Northwest Africa 2977. Mass Spectrometry 2023; 2: A0115.
[4]. X. Dai, J.H.F.L. Davies, Z. Yuan, Et Al. A Mesozoic Fossil Lagerstätte From 250.8 Million Years Ago Shows A Modern-Type Marine Ecosystem. Science 2023; 379: 567-572.
[5]. A.L. Thomas, G.M. Henderson, P. Deschamps, Et Al. Penultimate Deglacial Sea-Level Timing From Uranium/Thorium Dating Of Tahitian Corals. Science 2009; 324: 1186-1189.

ABSTRACT: This comprehensive study evaluated the dosimetric and clinical outcomes of three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), and volumetric modulated arc therapy (VMAT) in the treatment of localized prostate cancer. The analysis included 13 intermediate-risk prostate cancer patients (PSA levels 4-15 ng/mL, clinical stages T2a-T2c) who underwent treatment planning using five-field and seven-field 3D-CRT, five-field and seven-field IMRT, and single-arc VMAT (RapidArc) techniques. Detailed dosimetric......

Keywords: Prostate cancer, VMAT, IMRT, 3D-CRT, dosimetric analysis, PTV coverage, rectal sparing, cost-effectiveness, radiotherapy planning, treatment techniques

[1] Tanaka K, Sato H, Watanabe Y. Advanced VMAT Techniques For Prostate Cancer In Japanese Patients: A Multicenter Analysis. ISOR J Radiat Oncol. 2023;12(3):45-60.
[2] Yamada S, Nakamura T. Cost-Effectiveness Analysis Of Modern Radiotherapy Techniques In Tokyo Metropolitan Hospitals. Jpn J Clin Oncol. 2022;52(8):789-801.
[3] ESTRO Guidelines Committee. Prostate Cancer Radiotherapy: 2023 Clinical Practice Guidelines. Radiother Oncol. 2023;178:109-120.
[4] Kobayashi T, Suzuki M, Yamamoto H. Comparative Analysis Of 3D-CRT In Elderly Japanese Prostate Cancer Patients. ISOR J Radiat Oncol. 2021;10(2):33-44.
[5] Hashimoto M, Et Al. Organ Sparing In Prostate VMAT: Japanese Single-Institution Experience. Med Phys Jpn. 2022;18(4):112-125.

ABSTRACT: This paper shows the current theories that support or refute the end of the universe.Using the Friedmann equations, which are derived from Einstein's field equations, this work examines the expansion, curvature, and the roles of energy and dark matter in determining the fate of the universe. The equations were examined using the assumptions of homogeneity and isotropy in conjunction with observational data from projects such as WMAP and COBE, and......

Keywords: Friedmann equations, critical density, curvature of the universe, dark matter, dark energy, big freeze, big crunch.

[1] Cervantes-Cota, J. L., & Smoot, G. (2011). Cosmology Today-A Brief Review. Arxiv Preprint Arxiv:1107.1789
[2] Hirvonen, V. (N.D.-A). The Friedmann Equations Explained: A Complete Guide. Profound Physics.
Https://Profoundphysics.Com/The-Friedmann-Equations-Explained-A-Complete-Guide/
[3] 1: A Brief History Of The Universe With A Focus On The Domination Of... | Download Scientific Diagram. (N.D.-B).
Https://Www.Researchgate.Net/Figure/A-Brief-History-Of-The-Universe-With-A-Focus-On-The-Domi Nation-Of-Its-Different_Fig1_309730463
[4] Critical Density: Cosmos. Critical Density | COSMOS. (N.D.). Https://Astronomy.Swin.Edu.Au/Cosmos/C/Critical+Density

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ABSTRACT: A potential new fundamental force involving the detection of unusual particle decay at a high energy level of 4.8 TeV during experiments at CERN's Large Hadron Collider was recently discovered by Google AI. It suggests the presence of particles or interactions that do not fit within the current Standard Model of physics. On the other hand, according to Yangton and Yington Theory, all the subatomic particles in Standard Model including quarks, electron...

Keywords: Standard Model, Quantum Field Theory, Unified Field Theory, String Theory, Subatomic Particles, Yangton and Yington Theory, Five Principles of the Universe, Force of Creation, Wu’s Pairs, Yangton and Yington Particles, String Force, Higgs Field, Higgs Boson.

[1] Https://Lifeboat.Com/Blog/2025/06/Google-Ai-Just-Predicted-A-New-Fundamental-Force-In-Physics.
[2] Edward T. H. Wu, "Yangton And Yington–A Hypothetical Theory Of Everything", Science Journal Of Physics, Volume 2015, Article Id Sjp-242, 6 Pages, 2015, Doi: 10.7237/Sjp/242.
[3] Edward T. H. Wu. “Subatomic Particle Structures And Unified Field Theory Based On Yangton And Yington Hypothetical Theory”. American Journal Of Modern Physics. Vol. 4, No. 4, 2015, Pp. 165-171. Doi: 10.11648/J.Ajmp. 20150404.13.
[4] Polchinski, Joseph (1998). String Theory, Cambridge University Press Isbn 0521672295.
[5] Beyond Art: A Third Culture Page 199. Compare Uniform Field Theory.
[6] Edward T. H. Wu. “Space And Dark Matter Made Of Yangton And Yington Bubbles.” Iosr Journal Of Applied Physics (Iosr-Jap), 15(4), 2023, Pp. 06-13.

ABSTRACT: Topological entanglement entropy (TEE) provides a universal measure of long-range quantum correlations in topologically ordered systems, offering critical insights into exotic phases of matter. While theoretical frameworks, including exactly solvable lattice models, tensor networks, and field-theoretic approaches, enable precise computation of TEE in idealized settings, practical implementation faces multiple challenges. Finite-size and geometry effects, including boundary corners and lattice discretization, introduce significant corrections that can obscure the small topological contribution. Gapless edges in chiral topological phases further complicate...

Keywords: Topological order, Entanglement entropy, Topological entanglement entropy, Anyons, Symmetry-protected phases, Finite-size effects.

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[2]. Levin, M., & Wen, X.-G. (2006). Detecting topological order in a ground state wave function. Physical Review Letters, 96(11), 110405.
[3]. Wen, X.-G. (2017). Colloquium: Zoo of quantum-topological phases of matter. Reviews of Modern Physics, 89(4), 041004.
[4]. Nayak, C., Simon, S. H., Stern, A., Freedman, M., & Das Sarma, S. (2008). Non-Abelian anyons and topological quantum computation. Reviews of Modern Physics, 80(3), 1083–1159.
[5]. Hamma, A., Ionicioiu, R., & Zanardi, P. (2005). Ground state entanglement and geometric entropy in the Kitaev model. Physics Letters A, 337(1-2), 22–28.