decay process
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2022 ◽  
Vol 12 (2) ◽  
pp. 861
Author(s):  
Alba Patrizia Santo ◽  
Beatrice Agostini ◽  
Carlo Alberto Garzonio ◽  
Elena Pecchioni ◽  
Teresa Salvatici

Serpentinite is a low-grade metamorphic rock derived from the transformation of ultramafic rocks. Mainly because of its aesthetic characteristics it has been widely used as a building and ornamental stone. “Verde di Prato” is the most common local name used in Tuscany to refer to this type of rock, historically quarried in this area and used for many centuries in a large number of monuments of this region. In this paper, we report the results of a study carried out on the serpentinite from the pavement of the Florence baptistery, to properly characterize it from a physical point of view, describe the rock conservation state, and understand the phenomena responsible for its decay. The studied rock displays numerous forms of decay including fractures, loss of material, erosion, discolouration and efflorescence. X-ray diffractometer analyses of the efflorescence revealed the presence of numerous salts whose formation can be imputed to multiple, possibly concomitant, causes such as the high relative humidity and the variation of inside temperature, the presence of concrete and/or cementitious mortars in the subsoil, atmospheric pollution and the burial ground existing close the baptistery.


2022 ◽  
Author(s):  
Hai Ou ◽  
Mengkang Pei ◽  
qiang ren ◽  
Xiu Lan Wu ◽  
Enlong Yang ◽  
...  

Long afterglow luminescence material is an important energy storage material. For large-scale applications, the low afterglow brightness specially in slow decay process is a weak point. At present, the methods...


Author(s):  
玉轩 李 ◽  
Keke Ding ◽  
Haozhong Wu ◽  
Qing Wan ◽  
Yao Ma ◽  
...  

Recently, some discovery based on non-radiative decay process leading to photodynamic therapy or photothermal therapy has become an attaching hotspot, and how to achieve better performance is becoming important in...


2021 ◽  
Author(s):  
Shuyun Yang ◽  
Meng Jin ◽  
DeFu Hou

Abstract We study the mass spectra and decay process of σ and π0 mesons under strong external magnetic field. To achieve this goal, we deduce the thermodynamic potential in a two-flavor, hot and magnetized Nambu-Jona-Lasinio model. We calculate the energy gap equation through the random phase approximation (RPA). Then we use Ritus method to calculate the decay triangle diagram and self-energy in the presence of a constant magnetic field B. Our results indicate that the magnetic field has little influence on the mass of π0 at low temperatures. While for quarks and σ mesons, their mass changes obviously, which reflects the influence of magnetic catalysis (MC). The presence of magnetic field accelerates the decay of the meson while the presence of chemical potential will decrease the decay process. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.


Author(s):  
Yahui Wang ◽  
Tao Wang ◽  
Shizhao Wei ◽  
Zhiyong Qiu

Abstract The parametric decay process of a reversed shear Alfv\'{e}n eigenmeode (RSAE) into a geodesic acoustic mode (GAM) and a kinetic reversed shear Alfv\'{e}n eigenmode (KRSAE) is investigated using nonlinear gyrokinetic theory. The excitation conditions mainly require the pump RSAE amplitude to exceed a certain threshold, which could be readily satisfied in burning plasmas operated in steady-state advanced scenario. This decay process can contribute to thermal plasma heating and confinement improvement.


2021 ◽  
Author(s):  
manfred geilhaupt

Abstract In Quantum Physics, the Spin of an elementary particle is defined to be an intrinsic,inherent property. The same to the magnetic moment (μ) due to the spin of chargedparticles - like Electron (me) and Proton (mp). So the intrinsic spin (S=1/2h-bar) of theelectron entails a magnetic moment because of charge (e). However, a magnetic momentof a charged particle can also be generated by a circular motion (due to spin) of anelectric charge (e), forming a current. Hence the orbital motion (of charge around a massnucleus)generates a magnetic moment by Ampère’s law. This concept must lead to analternative way calculating the neutrino mass (mν) while looking at the beta decay of aneutron into fragments: proton, electron, neutrino and corresponding kinetic energies. Thechange of neutrons magnetic moment (μn) during the decay process is a fact based onenergy and spin and charge conservation, so should allow to calculate the restmass ofthe charge-less neutrino due to a significant change of: μe= -9.2847647043(28)E-24J/Tdown to μev= -9.2847592533(28)E-24J/T (while assuming mv=0.30eV to be absorbed and if(g-2)/2 from QED remains constant). As always the last word has the experiment.


2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Patrick Draper ◽  
Isabel Garcia Garcia ◽  
Benjamin Lillard

Abstract Bubbles of nothing are a class of vacuum decay processes present in some theories with compactified extra dimensions. We investigate the existence and properties of bubbles of nothing in models where the scalar pseudomoduli controlling the size of the extra dimensions are stabilized at positive vacuum energy, which is a necessary feature of any realistic model. We map the construction of bubbles of nothing to a four-dimensional Coleman-De Luccia problem and establish necessary conditions on the asymptotic behavior of the scalar potential for the existence of suitable solutions. We perform detailed analyses in the context of five-dimensional theories with metastable dS4× S1 vacua, using analytic approximations and numerical methods to calculate the decay rate. We find that bubbles of nothing sometimes exist in potentials with no ordinary Coleman-De Luccia decay process, and that in the examples we study, when both processes exist, the bubble of nothing decay rate is typically faster. Our methods can be generalized to other stabilizing potentials and internal manifolds.


2021 ◽  
Author(s):  
manfred geilhaupt

Abstract In Quantum Physics the Spin of an elementary particle is defined to be an „intrinsic, inherent“ property. The same to the magnetic moment (μ) due to the spin of charged particles - like Electron (me) and Proton (mp). So the intrinsic spin (S=1/2h-bar) of the electron entails a magnetic moment because of charge (e). However, a magnetic moment of a charged particle can also be generated by a circular motion (due to spin) of an electric charge (e), forming a current. Hence the „orbital motion of charge“ around a „mass-nucleus“ generates a magnetic moment by Ampère’s law. This concept leads to an alternative way calculating the neutrino mass (mν) while discussing the beta decay of a neutron into fragments: proton, electron, neutrino and binding energy. The change of neutrons magnetic moment (μn) during the decay process based on energy and spin and charge conservation should allow to calculate the restmass of the neutrino. 
(KATRIN <1.1eV (2019) about 0.2eV (2021). Estimation from μn: 0.10(20)eV (2020).


2021 ◽  
Author(s):  
manfred geilhaupt

Abstract In Quantum Physics the Spin of an elementary particle is defined to be an „intrinsic, inherent“ property. The same to the magnetic moment (μ) due to the spin of charged particles - like Electron (me) and Proton (mp). So the intrinsic spin (S=1/2h-bar) of the electron entails a magnetic moment because of charge (e). However, a magnetic moment of a charged particle can also be generated by a circular motion (due to spin) of an electric charge (e), forming a current. Hence the „orbital motion of charge“ around a „mass-nucleus“ generates a magnetic moment by Ampère’s law. This concept leads to an alternative way calculating the neutrino mass (mν) while discussing the beta decay of a neutron into fragments: proton, electron, neutrino and binding Energy. The change of neutrons magnetic moment during the decay process based on energy and spin and charge conservation allows to calculate the restmass of the neutrino: mν = 0.10(20)eV.


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