At present, due to the rapid development of THz technology in medical applications, it becomes urgent to develop stable test objects (phantoms) for calibration, optimization of the operation of devices, and verification of the research methods used. In this work, a five-component phantom has been developed based on water, glycerin, starch, bentonite, and gelatin, and it was shown that these phantoms can be used as indicators of the level of dehydration of the renal tumor tissue. The mechanical properties of the phantom were investigated, the dispersions of the refractive index and absorption coefficient of the biocomposite were determined in the range from 0.2 to 1 THz. To simulate the optical parameters of a phantom depending on the concentration of inclusions, an iterative method was developed and it was found that this method makes it possible to simulate the optical parameters of a phantom at low concentrations of bentonite. It is shown that in the structure of a five-component phantom, during fabrication, clusters of starch particles are formed, and the resonant interaction of the incident THz radiation with cluster particles leads to the excitation of whispering gallery modes.
The paper reports synthesis and co-crystallization of 5 co-crystal of 4-nitrophenol (4N) with five different monoand diaminopyridines (4-aminopyridine (4AP); 3,4-diaminopyridine (34DAP); 2-amino-6-methylpyridine (26MAP); 2,6- diaminopyridine (26DAP); 2-aminopyridine (2AP)) resulted in five adducts with the molar ratio of components 2:1 in final compounds. X-ray analysis confirms the non-centrosymmetric packing of obtained compounds. Two compounds crystallize in the polar acentric P21 and three compounds crystallize in acentric orthorhombic Pna21 space groups. The comparative studies on the laser induced multiple and single shot damage thresholds of named crystals were carried out using radiation of 1064 nm from Nd:YAG laser with pulse width 10 ns. Obtained results show good laser-induced singleshot and multiple-shot damage threshold values for all studied co-crystals and are found up to 3.64 GW/cm2 and 1.77 GW/cm2 respectively.
Kinetics of polymer microelements growing on the top of optical fiber with use of different photoactive additives (Rodamine B, Coumarin) was studied. Consequently, the technological principles of production of polymer self-adjoint microelements were founded