Actinium isotope cross sections for Ra(p,xn) reactions measured at low energies.

Cross sections for production of the medical isotope Ac by the Ra(p,2n) reaction have not previously been measured in fine steps over the relevant energy region, and no measurements are presently available in the literature for the actinium contaminant isotopes created by the adjacent Ra(p,n)Ac and Ra(p,3n)Ac reactions. We report thin-target cross-section measurements for production of Ac and Ac by protons of 15.1-16.

Impacts of technology on children's health: a systematic review.

Objective: To identify the consequences of technology overuse in childhood.

Data Source: A systematic review was carried out in the electronic databases PubMed (National Library of Medicine of the National Institutes of Health) and BVS (Virtual Health Library), considering articles published from 2015 to 2020, in English, Portuguese and Spanish using the terms "Internet", "Child" and "Growth and Development".

Data Synthesis: 554 articles were found and 8 were included in the analysis.

Secrecy Analysis and Error Probability of LIS-Aided Communication Systems under Nakagami- Fading.

Large intelligent surfaces (LIS) are a new trend to achieve higher spectral efficiency and signal-to-noise ratio in mobile communications. For this reason, this paper proposes metrics to analyze the performance of systems with multiple antennas aided by LIS and derive the spectral efficiency, secrecy outage probability, and bit error probability in an environment with Nakagami- distributed fading. In addition to an eavesdropper, there is a single-antenna user, an array of antennas at the transmitter side and the possibility of a direct link between transmitter and receiver.

Large Intelligent Surfaces Communicating Through Massive MIMO Rayleigh Fading Channels.

Large intelligent surfaces (LIS) promises not only to improve the signal to noise ratio, and spectral efficiency but also to reduce the energy consumption during the transmission. We consider a base station equipped with an antenna array using the maximum ratio transmission (MRT), and a large reflector array sending signals to a single user. Each subchannel is affected by the Rayleigh flat fading, and the reflecting elements perform non-perfect phase correction which introduces a Von Mises distributed phase error.

rp process and masses of N approximately Z approximately 34 nuclides.

High-precision Penning-trap mass measurements of the N approximately Z approximately 34 nuclides 68Se, 70Se, (70m)Br, and 71Br were performed, reaching experimental uncertainties of 0.5-15 keV. The new and improved mass data together with theoretical Coulomb displacement energies were used as input for rp process network calculations.

Discovery of a nuclear isomer in 65Fe with penning trap mass spectrometry.

A new long-lived isomeric state in (65)Fe has been discovered with Penning trap mass spectrometry and high-precision mass measurements of the neutron-rich isotopes (63-65)Fe and (64-66)Co have been performed with the Low-Energy Beam and Ion Trap Facility at the NSCL. For the new isomer in (65)Fe an excitation energy of 402(5) keV has been determined from the measured mass difference between the isomeric and ground states. The mass uncertainties of all isotopes have been reduced by a factor of 10-100 compared to previous results.

Experiments with thermalized rare isotope beams from projectile fragmentation: a precision mass measurement of the superallowed beta emitter 38Ca.

The mass of the short-lived radio nuclide 38Ca (T(1/2) = 440 ms) has been measured with the 9.4-T Penning trap mass spectrometer of the Low-Energy Beam and Ion Trap Facility. A mass uncertainty of deltam = 280 eV has been achieved, corresponding to deltam/m = 8 x 10(-9).