Analysis of the Effects of Tandem Welding (Fronius TPS/i - TWIN) of S1100QL and S1300QL Steels.

S1100QL and S1300QL steels are classified as fine-grained steels with a low-carbon martensitic structure. Tandem welding is a method of creating a joint by melting two electrode wires in a one-behind-the-other configuration. This article presents the effects of creating dissimilar joints, elements of varying thicknesses made from S1100QL and S1300QL steels.

Nonmaximal entanglement of photons from positron-electron annihilation demonstrated using a plastic PET scanner.

In state-of-the-art positron emission tomography (PET), information about annihilation photon polarization is unavailable. Here, we present a PET scanner built from plastic scintillators, where annihilation photons primarily interact via the Compton effect, providing information about both photon polarization and propagation direction. Using this plastic-based PET, we determined the distribution of the relative angle between polarization planes of photons from positron-electron annihilation in a porous polymer.

Realistic total-body J-PET geometry optimization: Monte Carlo study.

Background: Total-body (TB) Positron Emission Tomography (PET) is one of the most promising medical diagnostics modalities, opening new perspectives for personalized medicine, low-dose imaging, multi-organ dynamic imaging or kinetic modeling. The high sensitivity provided by total-body technology can be advantageous for novel tomography methods like positronium imaging, demanding the registration of triple coincidences. Currently, state-of-the-art PET scanners use inorganic scintillators.

Positronium image of the human brain in vivo.

Positronium is abundantly produced within the molecular voids of a patient's body during positron emission tomography (PET). Its properties dynamically respond to the submolecular architecture of the tissue and the partial pressure of oxygen. Current PET systems record only two annihilation photons and cannot provide information about the positronium lifetime.

Positronium lifetime validation measurements using a long-axial field-of-view positron emission tomography scanner.

Background: Positron emission tomography (PET) traditionally uses coincident annihilation photons emitted from a positron interacting with an electron to localize cancer within the body. The formation of positronium (Ps), a bonded electron-positron pair, has not been utilized in clinical applications of PET due to the need to detect either the emission of a prompt gamma ray or the decay of higher-order coincident events. Assessment of the lifetime of the formed Ps, however, can potentially yield additional diagnostic information of the surrounding tissue because Ps properties vary due to void size and molecular composition.