scholarly journals Сравнительный анализ спектров люминесценции алмазов

2019 ◽  
Vol 127 (9) ◽  
pp. 507
Author(s):  
С.И. Зиенко ◽  
Д.С. Слабковский
Keyword(s):  
Comparative Analysis ◽  
Crystal Lattice ◽  
Diamond Crystal ◽  
Relaxation Frequency ◽  
Luminescence Spectra ◽  
Time Range ◽  
Energy Losses ◽  
Q Factor ◽  
Bandwidth Parameter ◽  
Resonant Radiation

AbstractTo identify the signs that distinguish natural diamonds from artificial diamonds, a comparative analysis of the luminescence spectra with regards to the Q factor, center of gravity, bandwidth parameter, and energy losses in the diamond crystal lattice under conditions of ohmic and dielectric relaxation of luminescence is performed. The phenomenon of resonant luminescence in the femtosecond time range is detected in diamond. It is established that natural and artificial diamonds noticeably differ in the relaxation frequency and in the energy of resonant radiation.

scholarly journals Comparative analysis, design and optimisation of a 48 channel DWDM system using various design parameters

2019 ◽  
Author(s):  
◽  
Jerrin Zachariah Mohan
Keyword(s):  
Comparative Analysis ◽  
Design Parameters ◽  
Communication Link ◽  
Q Factor ◽  
Bit Rate ◽  
Analysis Model ◽  
Transmission Impairments ◽  
Compensation Technique ◽  
Linear Effects ◽  
Dwdm System

In the current era, there is an ever-growing demand for data hungry applications and services that need large amounts of bandwidth to send digital information at very high speeds. In order to meet this challenge for higher bandwidth capacity, Dense Wave Division Multiplexing (DWDM) is used as the strategy to transmit multiple high-bit rate channels at extremely narrow channel spacings over a single fiber core. However, this gives rise to detrimental transmission impairments such as linear effects and non-linear effects. The dissertation minimises the impairments by optimally designing a new DWDM system that produces a detectable and acceptable quality of signal at the receiver. In this dissertation, a comparative analysis is performed on the simulative design of a 48-channel DWDM system that has a 25 Gb/s bit rate and a 100 km transmission distance. The research mitigates the effects of transmission impairments such that an error-free matched communication link is produced for equally spaced (ES) channels of 100 GHz, 50 GHz, 25 GHZ and 12.5 GHz and 6.25 GHz. Various design parameters are used to create the comparative analysis model to optimise the 48 channel DWDM network. The design is simulated using the Optisystem simulation platform and the signal analysis is based on the bit error rate (BER) and quality (Q) factor of the received signal’s eye diagrams. It is established in the desertion that modified networks with matched active components has ES frequency channels that are aligned to each other and has a higher optical signal to noise ratio (OSNR) than mismatched networks. The maximum signal power and OSNR of the 3-erbium doped fiber amplifier (EDFA)-post symmetric compensation technique is always higher than the 1-EDFA post compensation technique for all channel spacings in any type of network. Modified duobinary return to zero (MDRZ) when compared to non-return to zero (NRZ) and return to zero (RZ) has a greater dispersion tolerance, higher fiber non-linearity tolerance and a higher acceptable signal transmission over longer distances with the least amount of errors. The optimised design parameter configurations produce the highest signal performance (highest Q factor > 6 and lowest BER > 10-9) and the highest bandwidth efficiency for the RZ Modulation (at 100 GHz, 50 GHz and 25 GHz channel spacings) and MDRZ Modulation (at 12.5 and 6.25 GHz channel spacing).

A Comparative Analysis of Dual-Order Bidirectional Pumping Schemes in Optical Fiber Raman Amplification

2019 ◽  
Vol 40 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Kulwinder Singh ◽  
Manjeet Singh Patterh ◽  
Manjit Singh Bhamrah
Keyword(s):  
Comparative Analysis ◽  
Fiber Length ◽  
Noise Figure ◽  
Signal To Noise Ratio ◽  
Optical Power ◽  
Optical Signal ◽  
Input Power ◽  
Q Factor ◽  
Wavelength Division ◽  
First Order

Abstract In this paper, dual-order bidirectional pumping schemes of distributed fiber Raman amplifier are compared with standard first-order pumping in wavelength division multiplexed optical transmission systems. The novel comparison analysis is carried out in terms of Optical signal-to-noise ratio and Q-factor, on-off gain and noise figure by varying optical input power and fiber lengths. The results indicate that dual-order schemes present 0.02 dB higher OSNR and 5 dB higher Q-factor in comparison to first-order pumping when input optical power is varied from −4 to 5 dBm. Similarly, there is 4 dB higher on-off gain with dual order comparatively to first order when fiber length varied from 10 to 100 km. However, there is degradation in noise figure and Q-factor due to DRBS noise with dual-order pumping when fiber length from 10 to 100 km. Further, the signal power evolutions along fiber length show that there is 5 dBm improvement for 100 km fiber. The novelty of the work is that comparative analysis exhibits improvement in OSNR, on-off gain and Q-factor using dual-order bidirectional pumping.

A Comparative Analysis of the Luminescence Spectra of Diamonds

2019 ◽  
Vol 127 (3) ◽  
pp. 564-570
Author(s):  
S. I. Zienko ◽  
D. S. Slabkovskii
Keyword(s):  
Comparative Analysis ◽  
Luminescence Spectra

scholarly journals The Comparative Analysis of Inductor and Reluctance Wind Generators

2009 ◽  
Vol 25 (25) ◽  
pp. 39-42 ◽  
Author(s):  
Edmunds Kamoliņš
Keyword(s):  
Comparative Analysis ◽  
Low Power ◽  
Permanent Magnets ◽  
Energy Losses ◽  
Wind Generators

The Comparative Analysis of Inductor and Reluctance Wind GeneratorsIn the presented work two designs of brushless generators are compared: inductor and reluctance. Both designs are multipolar and also can be applied as directly driven wind generators. Both one and the second designs are basically similar, but in the inductor generator are windings of excitation or permanent magnets which complicate a design, increase consumption of the copper and energy losses. In work shown that reluctance generator has no winding of excitation, it is simple and more reliable, it has less weight. It's more competitive for use in low power wind plants.

scholarly journals Структура R-=SUB=-1-=/SUB=- и R-=SUB=-2-=/SUB=- полос изотопов иона Cr-=SUP=-3+-=/SUP=- в монокристалле рубина при комнатной температуре

2021 ◽  
Vol 129 (4) ◽  
pp. 494
Author(s):  
В.С. Аракелян ◽  
Т.И. Бутаева ◽  
П.Г. Мужикян ◽  
Д.Г. Заргарян ◽  
Р.Б. Костанян
Keyword(s):  
Stable Isotopes ◽  
Comparative Analysis ◽  
Laser Diode ◽  
Room Temperature ◽  
Selective Excitation ◽  
Luminescence Spectra ◽  
Halogen Lamp ◽  
Combined Structure ◽  
Absorption And Luminescence Spectra ◽  
Excited Luminescence

Abstract. The absorption and luminescence spectra of the R1 and R2 bands in a ruby Al2O3:Cr3+ (0,05%) single crystal at room temperature were studied. The luminescence bands have been obtained both by excitation of the crystal by the radiation of a halogen lamp and by selective excitation of the two upper levels of the 2T1 state using the radiation of a laser diode with a tunable wavelength (656-662 nm). In the spectra of selectively excited luminescence bands, four different displacements of the R1 and R2 bands and four different distances between these bands have been detected, the change of which is a multiple of ~ 0.52 cm-1. A detailed comparative analysis of the obtained spectra of the luminescence bands and their absorption allowed us to determine the combined structure of each of the R1 and R2 bands, formed by additional doublets of these bands of all four stable isotopes of ions 50Cr3+, 52Cr3+, 53Cr3+ and 54Cr3+. The splitting of the obtained doublets varies from 7.04 to 9.14 cm-1 depend on the mass of the isotope

Synthesis and X-Ray Analysis of Complex Ferrites

2017 ◽  
Vol 744 ◽  
pp. 393-398 ◽  
Author(s):  
Mukhametkali Musagalievich Mataev ◽  
M.R. Abdraimova ◽  
S.M. Saxena ◽  
D.Zh. Nuketaeva ◽  
B.T. Zheksembieva
Keyword(s):  
Magnetic Field ◽  
Comparative Analysis ◽  
Crystal Lattice ◽  
Complex Oxides ◽  
Mixed Complex ◽  
X Ray ◽  
Unit Cells ◽  
First Time ◽  
The Relationship ◽  
Crystal Lattice Parameters

Ferrite with mixed complex oxides BiNaFe2O5, BiKFe2O5 was synthesized by high temperature solid state reaction. The structure of the ferrites, type of syngony, parameters of the unit cells, radiographic and pycnometric densities were determined by X-ray phase analysis for a first time: BiNaFe2O5 – а=5,577, с=13,86 Å, γ=120º, Vun.cell. = 373,9 Å3, Z=4, ρrad.= 7,5262 г/см3, ρpicn.=7,5271 г/см3, BiKFe2O5 –а=5,545, с=13,65 Å, γ=120º, Vun.cell.= 363,45Å3, Z=6, ρrad.= 8,0367, ρpicn.=8,0375 г/см3. A comparative analysis of the relationship between crystal lattice parameters with parameters of the crystal lattice of initial oxides and complex ferrites has been performed. Research dependence of the magnetic moment of the complex ferrite BiNaFe2O5 of the applied magnetic field at a constant temperature T = 6.1405 K showed a paramagnetic shift in the structure.

scholarly journals ARCHITECTURAL SOLUTIONS TO INCREASE THE ENERGY EFFICIENCY OF BUILDINGS / ARCHITEKTŪROS SPRENDINIAI, DIDINANTYS ENERGINĮ PASTATŲ EFEKTYVUMĄ

2012 ◽  
Vol 18 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Josifas Parasonis ◽  
Andrius Keizikas ◽  
Audronė Endriukaitytė ◽  
Diana Kalibatienė
Keyword(s):  
Energy Efficiency ◽  
Comparative Analysis ◽  
Renewable Resources ◽  
Climatic Conditions ◽  
Energy Losses

While designing the volume of a building, architectural solutions can be employed to achieve greater energy efficiency for the entire lifecycle of the building. However, currently this possibility is not sufficiently utilised. The paper provides a comparative analysis of architectural solutions, presenting the ones that not only allow for a reduction in energy losses through the external envelope of a building considering the local climatic conditions; but also make it possible to increase the use of energy from renewable resources. Santrauka Projektuojant pastatų tūrius yra galimybė, pasitelkus architektūrinius sprendinius, pasiekti didesnį energinį efektyvumą viso jų gyvavimo laikotarpiu, tačiau šiuo metu tuo naudojamasi nepakankamai. Darbe atlikta architektūrinių sprendinių lyginamoji analizė, kurios metu pristatomi sprendimai, leidžiantys sumažinti energijos, prarandamos per pastato išorės atitvaras, kiekį atsižvelgiant į vietos klimato sąlygas, bei padidinti pastato suvartojamos energijos kiekį naudojant atsinaujinančiųjų šaltinių energiją.

scholarly journals INFLUENCE OF LEAD IONS ON PHOTOLUMINESCENT PROPERTIES OF POLYMETHYL METACRYLATE /(Zn,Pb)S/CdS/(Zn,Pb)S COMPOSITIONS

2020 ◽  
Vol 63 (11) ◽  
pp. 82-87
Author(s):  
Anastasya A. Isaeva ◽  
Vladimir P. Smagin
Keyword(s):  
Methyl Methacrylate ◽  
Crystal Lattice ◽  
Glassy State ◽  
Luminescence Excitation Spectrum ◽  
Lead Ions ◽  
Structural Defects ◽  
Colloidal Synthesis ◽  
Luminescence Spectra ◽  
Colloidal Solutions ◽  
Poly Methyl Methacrylate

The paper presents the results of a study of the effect of lead ions on the photoluminescent properties of core / shell / shell nanostructures based on zinc and cadmium sulfides synthesized in situ during the formation of polyacrylate composition. ZnS/CdS/ZnS and (Zn,Pb)S/CdS/(Zn,Pb)S nanoparticles were obtained by colloidal synthesis in a medium of (poly) methyl methacrylate. Colloidal solutions are solidified to a glassy state by radical thermal polymerization of methyl methacrylate in a block. To initiate the polymerization, benzoyl peroxide was introduced into the solutions in an amount of 0.1% by weight of methyl methacrylate. The conclusion on the formation of nanosized particles of complex composition in the polymer matrix is made by comparing the luminescence and luminescence spectra of the compositions containing ZnS and CdS particles and their structure. In the photoluminescence spectra of the (poly) methyl methacrylate/(ZnS/CdS/ZnS) composition, two complex bands associated with crystal lattice defects of ZnS particles (380 - 530 nm) and CdS (530 - 840 nm) were detected. The excitation of photoluminescence occurs as a result of interband transitions of electrons in each of the semiconductor layers, as well as during transitions of electrons from the conduction band to defect levels located in the forbidden band of the semiconductor structure. In the luminescence excitation spectrum, they correspond to bands of various intensities in the range of 300–420 nm and 300–480 nm. From the overlap of the ZnS luminescence bands and the excitation of CdS luminescence, it was concluded that the radiation of the core is absorbed by the CdS coating layer and that energy is transferred from the levels of structural defects of ZnS to the levels of structural defects of CdS at the layer boundary. Doping of zinc sulfide layers with lead ions leads to a change in the luminescence spectrum in the region of 380 - 530 nm and the disappearance of the CdS luminescence band in the range of 530 - 840 nm. The observed changes are associated with defects that create Pb2+ ions in the crystal lattice of the ZnS outer shell and the screening of the (Zn,Pb)S shell of the inner layers from the penetration of exciting radiation.

scholarly journals Poziom rozwoju społeczno-gospodarczego w powiatach województwawielkopolskiego

2019 ◽  
pp. 37-49
Author(s):  
Karolina Józefowicz ◽  
Kinga Smolińska
Keyword(s):  
Economic Development ◽  
Comparative Analysis ◽  
Economic Aspect ◽  
Time Range ◽  
Economic Aspects ◽  
Socio Economic Development ◽  
The Relationship ◽  
Demographic Potential

The purpose of this article is to assess the level of socio-economic development of the poviats of the Wielkopolskie voivodship. The time range covered two periods: 2005–2007 and 2015–2017, within which values of the adopted features were averaged. The research carried out with the help of a synthetic Hellwig development measure allowed for a comparative analysis of poviats and observation of changes that occurred in the examined periods. The extended scope of observations indicated their importance in terms of separate socio-economic aspects. In addition, the relationship between demographic, economic, infrastructural and environmental potential was observed. An example is the poviats of the eastern part of Wielkopolska. Adverse changes in the sphere of demographic potential have moved to the economic aspect and have determined the level of socio-economic development.

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