3,385 research outputs found

    Analysis of the Energy Deposit in the Air by Radiation of Alpha Particles Emitted by the Water of a Spring Through the Geant4 Software

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    This work presents the development of an analysis of the potential radiological risk generated by alpha particles emitted by radon-222, content in a spring water, for the population that usually swims in the place and for the people who live near this spring. This spring is located in the state of Puebla. Several measurements in the water of this place by researchers from IF-UNAM showed that it contains an average radon concentration level of 70 Bq/m3. To evaluate this radiological risk, it has been developed a computational simulation to know the area and the height where the alpha particles deposit their energy to the medium, as well as the amount of energy that they transfer. This simulation was developed in the Geant4 scientific software and the calculations were executed in the supercomputer of the Laboratorio Nacional de Supercomputo del Sureste de Mexico of the BUAP. The results show that the energy deposit occurs within the superficial limits of the spring, between 7 and 8 meters high. This deposited is not only by the alpha particles, but also by the secondary particles that are generated by the interaction of alpha particles with the environment. Based on these results, it is confirmed that there is no radiological risk by energy deposit by alpha particles for the people

    Clinical subgroups in bilateral meniere disease

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    Meniere disease (MD) is a heterogeneous clinical condition characterized by sensorineural hearing loss, episodic vestibular symptoms, and tinnitus associated with several comorbidities, such as migraine or autoimmune disorders (AD). The frequency of bilateral involvement may range from 5 to 50%, and it depends on the duration of the disease. We have performed a two-step cluster analysis in 398 patients with bilateral MD (BMD) to identify the best predictors to define clinical subgroups with a potential different etiology to improve the phenotyping of BMD and to develop new treatments. We have defined five clinical variants in BMD. Group 1 is the most frequently found, includes 46% of patients, and is defined by metachronic hearing loss without migraine and without AD. Group 2 is found in 17% of patients, and it is defined by synchronic hearing loss without migraine or AD. Group 3, with 13% of patients, is characterized by familial MD, while group 4, that includes 12% of patients, is associated by the presence of migraine in all cases. Group 5 is found in 11% of patients and is defined by AD. This approach can be helpful in selecting patients for genetic and clinical research. However, further studies will be required to improve the phenotyping in these clinical variants for a better understanding of the diverse etiological factors contributing to BMD

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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