http://dspace.nbuv.gov.ua:80/handle/123456789/150315 Wed, 15 Apr 2026 08:18:52 GMT 2026-04-15T08:18:52Z http://dspace.nbuv.gov.ua:80/bitstream/id/448062/ http://dspace.nbuv.gov.ua:80/handle/123456789/150315 http://dspace.nbuv.gov.ua:80/handle/123456789/154465 Influence of surface treatment conditions for organic crystalline scintillators on their scintillation characteristics Tarasov, V.O.; Andryushchenko, L.A.; Dudnik, O.V.; Rybka, E.A. The scintillation and optical characteristics of alpha and beta radiation detectors based on organic crystalline scintillators are investigated after the treatment of their surfaces with different compositions. The polishing composition has been matched, which ensures an improvement in the quality of the polished surface and an improvement in the stated characteristics of alpha and beta radiation detectors based on stilbene and activated p-terphenyl single crystals by increasing the light collection coefficient. The parameters of these detectors are retained after exposure to a temperature of +60°C for 12 h. It is also shown that the use of a matched polishing compound makes it possible to obtain a detector of high spectrometric quality based on an activated p-terphenyl single crystal 6×6×6 mm³ in coupling with a SiPM. The energy resolutions for this detector are 5.7, 7.9 and 11.9 % when electrons of internal conversion with energies of 1048, 976 and 554 keV are being registered. Mon, 01 Jan 2018 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/154465 2018-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/154464 Three-dimensional generalization and verification of structured bounding surface model for natural clay Cui Yunliang; Wang xinquan; Zhou lianying As the proposed structured bounding surface model can only be used to solve planar strain problems of natural soft clay, a three-dimensional adaptive failure criterion is adopted to improve the model to capture the three-dimensional behaviors of natural soft clay. The three-dimensional adaptive failure criterion incorporated in this model can cover the Lade-Duncan criterion and the Matsuoka-Nakai criterion as its special ones. The structured bounding surface model is generalized into three-dimensional stress space by using the three-dimensional adaptive failure criterion. After improved with the three-dimensional adaptive failure criterion, the model can be seen as a modified bounding surface model which considers the destructuration and three-dimensional behaviors and neglects the anisotropy of natural soft clay. The simulations of undrained compression and extension tests of K0 consolidation state Bothkennar clay shows the unimportance of neglecting anisotropy in this model. It was validated on Pisa clay that the improved model can simulate well the three dimensional behaviors of natural soft clay under true triaxial conditions. Mon, 01 Jan 2018 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/154464 2018-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/154463 Structure, Crystallization and Thermal Behavior of Fluorinated ethylene propylene (FEP) based Plastics Composites Chen Jian-bing; Li Zhun-zhun; Xu Nan The FEP based binary and ternary plastics composites were prepared by melt blending. The microstructure, crystallization behavior and thermal degradation behavior of FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites were investigated by FT-IR, SEM, DSC, XRD and TGA. The FT-IR, SEM and DSC results shows that the FEP/PEEK, FEP/PEI and FEP/PEEK/PEI composites were presented thermodynamics incompatible. The degree of crystallinity of FEP was decreased as PEEK or with PEI simultaneously were added to FEP matrix, while the degree of crystallinity of FEP increases first then decreases as PEI was added to FEP matrix. The TGA results shows that the thermal stability of FEP/PEEK composites enhance with PEEK content increases when the PEEK content is under 25%, then decreased when the PEEK content is over 25%, the thermal stability of FEP/PEI and FEP/PEEK/PEI composites decreased with PEI or PEEK added to the FEP matrix. Mon, 01 Jan 2018 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/154463 2018-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/154462 Chemical-dynamic polishing of InAs, InSb, GaAs and GaSb crystals with (NH₄)₂Cr₂O₇-HBr-citric acid etching composition Levchenko, I.V.; Tomashyk, V.M.; Stratiychuk, I.B.; Malanych, G.P.; Stanetska, A.S.; Korchovyi, A.A. The chemical dissolution of InAs, InSb, GaAs and GaSb crystals in (NH₄)₂Cr₂O₇-HBr-C₆H₈O₇ etching solutions has been investigated. The dissolution rate of the semiconductor materials has been measured as a function of etchant composition, stirring rate and temperature. The limiting stages of dissolution process, regions of the polishing and unpolishing solutions have been established. The polishing etchant compositions and conditions for chemical-dynamic polishing of the InAs, InSb, GaAs and GaSb crystals have been proposed and optimized. Mon, 01 Jan 2018 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/154462 2018-01-01T00:00:00Z