Eu-doped SrAl2O4 is a promising thermoluminescent and mechanoluminescent material with high brightness and stability, making it suitable for various luminescent devices. In this study, SrAl2O4:Eu was synthesized using a solid-state reaction method, and the effects of reducing atmosphere and high-temperature synthesis conditions on its luminescence properties were systematically analyzed. The luminescence characteristics of SrAl2O4:Eu were found to be highly sensitive to synthesis temperature, atmosphere, and Eu doping concentration, and optimal conditions were determined. A comparison of SrAl2O4:Eu synthesized at 1,300 °C under air and reducing atmospheres revealed that the reducing atmosphere plays a critical role in stabilizing Eu2+ ions, forming a single-phase SrAl2O4, and establishing luminescence centers. Notably, SrAl2O4:Eu synthesized at 1,600 °C in a reducing atmosphere achieved a photoluminescence quantum yield (PLQY) of 43 % and a maximum luminance of 2,030 Cd/m2, showing significant improvement in luminescence efficiency compared to samples synthesized at 1,300 °C. When Eu doping concentrations were adjusted from 1 % to 20 %, the highest luminescence performance was observed at 10 % doping, while excessive doping (20 %) increased non-radiative recombination pathways, and no further improvement in luminescence efficiency was observed. X-ray Diffraction (XRD) and Photoluminescence (PL) analyses elucidated the effects of synthesis conditions on the structural stability and luminescence properties of SrAl2O4:Eu, and the optimal reducing atmosphere and high-temperature synthesis conditions are proposed. This study provides a synthesis strategy for enhancing the luminescence properties of Eu-doped SrAl2O4 and lays the groundwork for the development of highperformance thermoluminescent and mechanoluminescent materials.

‘Tracers’ are bullets that emit light at the backside so that the shooter can see the trajectory of their flight. These light-emitting bullets allow snipers to hit targets faster and more accurately. Conventional tracers are all combustion type which use the heat generated upon ignition. However, the conventional tracer has a fire risk at the impact site due to the residual flame and has a by-product that can contaminate the inside of the gun and lead to firearm failure. To resolve these problems, it is necessary to develop non-combustion-type tracers that can convert heat to luminance, so-called ‘thermoluminescence (TL)’. Here, we highly improve the thermoluminescence properties of MgB4O7 through co-doping of Dy3++Ce3+ and Dy3++Na+. The presence of doping materials (Dy3+, Ce3+, Na+) was confirmed by XPS (X-ray photoelectron spectroscopy). The as-synthesized co-doped MgB4O7 was irradiated with a specific radiation dose and heated to 500 °C under dark conditions. Different thermoluminescence characteristics were exhibited depending on the type or amounts of doping elements, and the highest luminance of 370 cd/m2 was obtained when Dy 10 % and Na 5 % were co-doped.

T. S. Eliot, in one of his later poetic dramas, The Conjìdential Clerk, shows the search for the mistaken identity dealing with lhe discovery of hero' s self for the eternal life in 버e common lives. From the titlc onwards the play also suggests a detective thriller interest concerned with Lhe investigation of a mystery or, at least, some business of a secret, confidential nature. In this respect, lhe elemenls of mystery and lheir function deserve to be analyzed. It appears via the elements of investigal.ion. coincidence. mystjfication, confession etc., which make the play fairly diverting and at the same time suggest symbolically its deeper meaning and lheme. AClually the process of invesligalion receives more extended treatment in this play than in I.he earlier ones. and the suspense is so well maintained that the play definitely achieves a technical smoothness 1101 to be seen in earlier plays. Therefore, this study aims to analyze the myslery lhriller elements of tbe play, The COlljìdential Clerk and investigate how they are used with special reference to its subject matter, the mistaken identity revealed in the process of self-identification through the discovery of self. As seen in the analysis, Eliot makes all the characters take part in the search for the mistaken identity of Colby Simpkins and in particular, lets a detective named Eggerson help M rs Guzzard as witness give evidence. 10 addition, he designs the story so that Eggerson can bring the whole affair to light by getting lhe c1ue to lhe identity problem which plays part in investigation. It matters that the discovery of hero’s true self is made Ihanks 10 the cooperalive efforts of all Ihe characlers in Ihis process, and here Ihe elemenls required 10 invesligation are of great help to structuring the basic frame of Ihe play.