scholarly journals Luminescent Properties of Composite Systems Based on Polystyrene and Erbium(III) Phthalocyaninates in Near IR Spectral Region

2018 ◽  
Vol 1 (3) ◽  
pp. e00029
Author(s):  
I.A. Belogorokhov ◽  
L.I. Belogorokhova ◽  
Yu.V. Ryabchikov ◽  
V.E. Pushkarev
Keyword(s):  
Comparative Analysis ◽  
Composite Materials ◽  
Wavelength Region ◽  
Luminescent Properties ◽  
Short Wavelength Region ◽  
Composite Systems ◽  
Near Ir ◽  
Polystyrene Matrix ◽  
First Time ◽  
Properties Of Composites

Composite materials based on polystyrene and ErIII phthalocyaninates of single-, double- and triple-decker structure were obtained, and their spectral luminescent characteristics in the near-IR (NIR) range were studied. All the ErIII complexes in these composites reveal 4f photoluminescence (PL), which is observed at 1550 nm for mono- and tris(phthalocyaninate), whereas in the case of bis(phthalocyaninate), the PL maximum is shifted to the short-wavelength region and appears at 1440 nm. A comparative analysis of the properties of composites and individual phthalocyanine compounds in films and solutions was carried out. In the case of a single-decker complex, this emission was detected for the first time in the polystyrene matrix, while for individual ErIII mono(phthalocyaninates), this process was not observed earlier.

scholarly journals Люминесцентные свойства нестехиометрических кристаллов ниобата лития различного состава и генезиса (обзор)

2022 ◽  
Vol 130 (1) ◽  
pp. 171
Author(s):  
М.В. Смирнов ◽  
Н.В. Сидоров ◽  
М.Н. Палатников
Keyword(s):  
Wave Spectrum ◽  
Visible Region ◽  
Wavelength Region ◽  
Visible Spectrum ◽  
Luminescent Properties ◽  
Short Wave ◽  
Octahedral Cluster ◽  
Short Wavelength Region ◽  
Luminescence Centers ◽  
Near Ir

A brief review of the features of the defect structure and studies of the luminescent properties of nonlinear optical lithium niobate crystals of various compositions and genesis was given. It was established that the electron-hole pair NbNb4+-O- in the oxygen-octahedral cluster NbO6 emitted in the short-wavelength region of the visible spectrum (400-500 nm), while point defects (VLi and NbNb4+-NbLi4+ bipolarons) - in the long-wavelength region (500-620 nm). At the ratio of Li/Nb≈1 the luminescence was extinguished in the visible region of the spectrum due to decreasing the intrinsic luminescence centers. It was shown that the presence of polaron luminescence in the near-IR region (700-1050 nm) was due to the small polarons NbLi4+ and impurity ions Cr3+ localized in lithium and niobium octahedra. The energy transfer between the luminescence centers in the visible and near-IR spectral regions was detected. Moreover, luminescence in near-IR regions was dominant. Doping of LiNbO3 crystals with zinc and magnesium at ZnO<4.46 mol.% and MgO<5.29 mol.% led to decreasing luminescence of intrinsic defects (VLi, NbNb4+-NbLi4+). However, there was an increase of the contribution of the short-wave spectrum component at higher dopant concentrations because of the introduction of Zn and Mg into the origin positions of Nb ions.

scholarly journals Inventory of the Kirillo-Belozersky Monastery (1615): An Experience of Using Spectrosonal Visualization to Reconstruct the History of the Text

2021 ◽  
pp. 651-664
Author(s):  
Evgeny A. Lyakhovitskii ◽  
Keyword(s):  
Visible Region ◽  
Wavelength Region ◽  
Main Text ◽  
Additional Information ◽  
Near Ir ◽  
Color Differences ◽  
History Of ◽  
High Degree ◽  
First Time ◽  
Made In

The article describes the results of a codicological study of the Inventory of the Kirillo-Belozersky (St. Cyrill of Beloozero) Monastery (1615). The main codicological problem for the researchers posed by this monument is its numerous and asynchronical edits. It is possible to identify edit layers by studying the ink by means of spectrosonal imaging in near-IR wavelength region of the spectrum. This method is based on the property of inks (except those with a carbon base) to acquire transparency beyond the visible region of the spectrum (after 700 nm). As additional information, visually observed (in natural indirect daylight) color differences between inks have been used, as well as color estimation using a digital portable microscope Dinolite with Dinoscope software. As a result of the study, the main stages of work on the Inventory have been established. A significant part of the marginalia are in the same ink and handwriting as the main text: brown, with moderate transparency in near-IR wavelength region. Thus, the text was probably supplemented in the course of creation. This edit was accompanied by the text on the insert sheets made in ink that is slightly translucent in the IR region of the spectrum and has a dark brown color. The same ink was used in the main text of the manuscript. When the main text was rewritten in 1616-1617, it was compiled in a codex and significantly revised for the first time. The marker of this revision stage is light brown and yellowish-brown ink with high degree of transparency in IR wavelength region of the spectrum. In addition to the editing, the notebooks are numbered in the same light brown ink. The edit of this layer mainly included clarifications to the items description. The next significant revision of the inventory text, marked with brown ink that has low transparent in the IR wavelength region of the spectrum, refers to the period after July 22, 1621. Most of these edits, as well as the earlier ones, were devoted to clarifying descriptions, to clarifying location of objects, and to describing the monastery’s acquisitions and losses. Apparently, the later stage of editing is associated with the use of gray-brown ink, similar in spectral behavior to the ink of the main text. The record of the contribution of Prince Khvorostinin made in 1622–23 was written in this ink.

Optical Properties of Chemical Vapour Etching Based Porous Silicon for Multicrystalline Solar Cells

2017 ◽  
Vol 23 ◽  
pp. 56-62
Author(s):  
Bedra Mahmoudi ◽  
Ahmed Mouhoub ◽  
Brahim Mahmoudi ◽  
Hamid Menari ◽  
Abdennour Mougas
Keyword(s):  
Optical Properties ◽  
Porous Silicon ◽  
Chemical Vapour ◽  
Wavelength Region ◽  
Multicrystalline Silicon ◽  
Short Wavelength Region ◽  
Solar Cell Application ◽  
Hydrogen Incorporation ◽  
Near Ir ◽  
Before And After

In this paper, we report a study on the possibility of fabricating porous silicon by exposing a multicrystalline silicon surface to gaseous etchants. The structural and optical properties of porous silicon (PS) layers prepared by vapour –etching (VE) are investigated. FTIR analysis confirms the existence of hydrogen incorporation bonding to the silicon atoms. Photoluminescence measurements reveal an efficient emission around 640 nm. The optical behaviour in the 350-1000 nm wavelength range was determined before and after PS formation, resulting in a notable reduction of reflectance and an enlargement of low reflectance region into short wavelengths and near IR region after PS formation. A significant increase of the quantum efficiency particularly in the short wavelength region is observed. The results make the use of such thin film very promising for multicrystalline silicon solar cell application.

scholarly journals SPECTRAL-LUMINESCENT PROPERTIES OF SOME NEW DIHYDROXY-2H-1-BENZOPYRAN-2-ONES SYNTHESIZED BASED ON 2,4,6-TRIHYDROXYTOLUENE

2020 ◽  
Vol 63 (9) ◽  
pp. 37-42
Author(s):  
Dmitry N. Kuznetsov ◽  
Konstantin I. Kobrakov ◽  
Sergey S. Bobylev
Keyword(s):  
Quantum Yield ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Wavelength Region ◽  
Sharp Decrease ◽  
Luminescent Properties ◽  
Long Wavelength ◽  
Wavelength Absorption ◽  
First Time ◽  
Derivatives Of

2,4,6-trihydroxytoluene (methylphloroglucinol) is a promising reagent in organic synthesis, after development out getting it from 2,4,6-trinitrotoluene. We previously synthesized of derivatives of 5,7-dihydroxy-2H-1-benzopyran-2-ones by the interaction of 2,4,6-trihydroxytoluene and 2,4,6 -trihydroxy-3-methylbenzoic acid with polyfunctional carbonyl compounds. The first time, a detailed analysis of the electronic absorption and fluorescence spectra of derivatives of 5,7-dihydroxy-2H-1-benzopyran-2-ones is carried out. In the electronic absorption spectra of the studied compounds, the absorption in the long-wavelength region of the spectrum is determined by electronic transitions with intramolecular charge carry. The possibility of controlling the bathochromic or hypsochromic shift of the long-wavelength absorption band by introducing substituents of various electronic nature into the molecule has been revealed. It was shown that some of the studied compounds have pronounced luminescence in the blue-green region of the spectrum (390–508 nm) with a quantum yield of 9–40%. The highest quantum yield (38%) was achieved when the 5,7-dihydroxy-2H-1-benzopyran-2-one carboxyl group was introduced into position 6. The bromination of this compound leads to a decrease in the quantum yield to 9.5 % The introduction into the 3 position of 5,7-dihydroxy-4,8-dimethylchromen-2-one phenyl substituted fragment along with O-acylation leads to a sharp decrease in the quantum yield. It is concluded that the studied objects are promising as basic structures for the search for new biosensors.

Anisotropic Elasticity

1996 ◽  
Author(s):  
T. T. C. Ting
Keyword(s):  
Composite Materials ◽  
Elastic Constants ◽  
Piezoelectric Materials ◽  
Anisotropic Materials ◽  
Anisotropic Elasticity ◽  
Stress Singularities ◽  
Comprehensive Survey ◽  
The Subject ◽  
Key Topics ◽  
First Time

Anisotropic Elasticity offers for the first time a comprehensive survey of the analysis of anisotropic materials that can have up to twenty-one elastic constants. Focusing on the mathematically elegant and technically powerful Stroh formalism as a means to understanding the subject, the author tackles a broad range of key topics, including antiplane deformations, Green's functions, stress singularities in composite materials, elliptic inclusions, cracks, thermo-elasticity, and piezoelectric materials, among many others. Well written, theoretically rigorous, and practically oriented, the book will be welcomed by students and researchers alike.

Intuitionistic fuzzy two-factor variance analysis of movie ticket sales

2021 ◽  
pp. 1-11
Author(s):  
Velichka Traneva ◽  
Stoyan Tranev
Keyword(s):  
Comparative Analysis ◽  
Real Data ◽  
Intuitionistic Fuzzy Sets ◽  
Real Numbers ◽  
Data Set ◽  
Important Method ◽  
Ticket Sales ◽  
Intuitionistic Fuzzy ◽  
The One ◽  
First Time

Analysis of variance (ANOVA) is an important method in data analysis, which was developed by Fisher. There are situations when there is impreciseness in data In order to analyze such data, the aim of this paper is to introduce for the first time an intuitionistic fuzzy two-factor ANOVA (2-D IFANOVA) without replication as an extension of the classical ANOVA and the one-way IFANOVA for a case where the data are intuitionistic fuzzy rather than real numbers. The proposed approach employs the apparatus of intuitionistic fuzzy sets (IFSs) and index matrices (IMs). The paper also analyzes a unique set of data on daily ticket sales for a year in a multiplex of Cinema City Bulgaria, part of Cineworld PLC Group, applying the two-factor ANOVA and the proposed 2-D IFANOVA to study the influence of “ season ” and “ ticket price ” factors. A comparative analysis of the results, obtained after the application of ANOVA and 2-D IFANOVA over the real data set, is also presented.

scholarly journals S-N Curve Characterisation for Composite Materials and Prediction of Remaining Fatigue Life Using Damage Function

2021 ◽  
Vol 5 (3) ◽  
pp. 76
Author(s):  
Ho Sung Kim ◽  
Saijie Huang
Keyword(s):  
Fatigue Life ◽  
Composite Materials ◽  
Loading Rate ◽  
Theoretical Method ◽  
Damage Function ◽  
Simple Method ◽  
Arbitrary Choice ◽  
Number Of Cycles ◽  
First Time ◽  
Remaining Fatigue Life

S-N curve characterisation and prediction of remaining fatigue life are studied using polyethylene terephthalate glycol-modified (PETG). A new simple method for finding a data point at the lowest number of cycles for the Kim and Zhang S-N curve model is proposed to avoid the arbitrary choice of loading rate for tensile testing. It was demonstrated that the arbitrary choice of loading rate may likely lead to an erroneous characterisation for the prediction of the remaining fatigue life. The previously proposed theoretical method for predicting the remaining fatigue life of composite materials involving the damage function was verified at a stress ratio of 0.4 for the first time. Both high to low and low to high loadings were conducted for predicting the remaining fatigue lives and a good agreement between predictions and experimental results was found. Fatigue damage consisting of cracks and whitening is described.

Improvement of Electrical Insulating and Anti-Wear Properties of Composites Used in Telemetry Systems

2015 ◽  
Vol 792 ◽  
pp. 578-581
Author(s):  
A.R. Gallyamov ◽  
I.D. Ibatullin ◽  
A.Y. Murzin
Keyword(s):  
Composite Materials ◽  
Epoxide Resin ◽  
Wear Properties ◽  
Research Results ◽  
Tribotechnical Properties ◽  
Properties Of Composites

This article deals with the research results of electroinsulated and tribotechnical properties of composite materials on the basis of epoxide resin. The effect of fillers — micro-and nanopowders of various materials - on the properties of composites is examined. The use of composites in the manufacture of separators for telemetry systems is demonstrated.

A Method to Evaluate the Elastic Properties of Ceramics-Enhanced Composites Undertaking Interfacial Delamination

2007 ◽  
Vol 336-338 ◽  
pp. 2513-2516
Author(s):  
Hua Jian Chang ◽  
Shu Wen Zhan
Keyword(s):  
Composite Materials ◽  
Present Method ◽  
Present Model ◽  
Constitutive Law ◽  
Layer Model ◽  
Interfacial Delamination ◽  
Equivalent Inclusion Method ◽  
Equivalent Inclusion ◽  
Micromechanical Approach ◽  
Properties Of Composites

A micromechanical approach is developed to investigate the behavior of composite materials, which undergo interfacial delamination. The main objective of this approach is to build a bridge between the intricate theories and the engineering applications. On the basis of the spring-layer model, which is useful to treat the interfacial debonding and sliding, the present paper proposes a convenient method to assess the effects of delamination on the overall properties of composites. By applying the Equivalent Inclusion Method (EIM), two fundamental tensors are derived in the present model, the modified Eshelby tensor, and the compliance tensor (or stiffness tensor) of the weakened inclusions. Both of them are the fundamental tensors for constructing the overall constitutive law of composite materials. By simply substituting these tensors into an existing constitutive model, for instance, the Mori-Tanaka model, one can easily evaluate the effects of interfacial delamination on the overall properties of composite materials. Therefore, the present method offers a pretty convenient tool. Some numerical results are carried out in order to demonstrate the performance of this model.

The Design of Composite Materials For Electro-Mechanical and Electro-Thermal Applications.

1983 ◽  
Vol 24 ◽  
Author(s):  
L. E. Cross
Keyword(s):  
Composite Materials ◽  
Figure Of Merit ◽  
Poisson Ratio ◽  
Dielectric Behavior ◽  
Thermal Mass ◽  
Secondary Effects ◽  
Pressure Sensing ◽  
Composite Systems ◽  
Reinforced Composite ◽  
Composite Microstructure

ABSTRACTIn composite materials for electro-mechanical applications, the importance of the mode in which the constituent phases are interconnected (connectivity) was stressed. For the tensor properties of mechanical, piezoelectric, and dielectric behavior, controlling the manner in which fields and fluxes thread through the composite can make orders of magnitude change in the coupled properties.Examples were drawn from piezoelectric ceramic:polymer composites for uniaxial and hydrostatic (hydrophone) pressure sensing where the 1:3 connected transversely reinforced composite can be shown to exhibit a figure of merit more than 103 that of the piezoceramic phase alone. In these systems, the importance of poisson ratio effects in the polymer phase were evident, and some new composite systems where the hydrostatic stiffness of the elastomer phases may be better exploited were considered.In electro-thermal applications such as in pyroelectric composites, the requirements of small-size and low-thermal mass put rigorous limits upon the scale of the composite microstructure. Techniques which achieve the appropriate scaling were described and preliminary data showed strong enhancement of the secondary effects in these composites were presented.

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