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Method for Determining the Effective Concentration of Solar Energy in Concentrating Photovoltaic Systems
IF 0.5 4区 物理与天体物理
Journal of Contemporary Physics (Armenian Academy of Sciences) Pub Date : 2025-03-16 DOI: 10.1134/S1068337225700197
R. R. Vardanyan, A. R. Gharakeshishyan
{"title":"Method for Determining the Effective Concentration of Solar Energy in Concentrating Photovoltaic Systems","authors":"R. R. Vardanyan,&nbsp;A. R. Gharakeshishyan","doi":"10.1134/S1068337225700197","DOIUrl":"10.1134/S1068337225700197","url":null,"abstract":"<p>Solar concentrator photovoltaics (CPV) technology is one of the promising methods for increasing the efficiency of solar energy conversion. In CPV systems, the luminous flux absorbed by the photodetector (photovoltaic module or solar cell) depends on the reflectivity of the concentrator surface, which is a function of the angle of incidence of light. The absorbed luminous flux also depends on the relative angular transmission of light into the photovoltaic module. In this paper, we propose a refined method for determining the absorbed luminous flux by the photodetector using the concept of effective light concentration. The proposed method considers the angular dependence of the specular reflection coefficient of light, as well as the relative angular transmission of light into the photovoltaic module. As an example, two specularly reflecting CPV systems are considered – planar and V-shaped.</p>","PeriodicalId":623,"journal":{"name":"Journal of Contemporary Physics (Armenian Academy of Sciences)","volume":"59 4","pages":"420 - 425"},"PeriodicalIF":0.5,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Electron Mobility Fluctuations in Polar Semiconductors
IF 0.5 4区 物理与天体物理
Journal of Contemporary Physics (Armenian Academy of Sciences) Pub Date : 2025-03-16 DOI: 10.1134/S1068337225700227
T. A. Zalinyan, S. V. Melkonyan
{"title":"Electron Mobility Fluctuations in Polar Semiconductors","authors":"T. A. Zalinyan,&nbsp;S. V. Melkonyan","doi":"10.1134/S1068337225700227","DOIUrl":"10.1134/S1068337225700227","url":null,"abstract":"<p>Some problems related to electron mobility fluctuations in polar semiconductors are discussed. The theory of electron-polar optical phonon field-induced tunnel scattering has been developed. Based on the obtained relation for the scattering rate in the case of weak fields, it was shown that in the presence of an electric field, the electron mobility variance takes on finite values, in contrast to the absence of a field, when it diverges. Using GaAs as an example, the dependence of the electron mobility variance on the electric field is computed, which is given by the decreasing function according to the logarithmic law. The frequency dependence of the spectral density of mobility fluctuations in polar semiconductors has the same qualitative form as in non-polar semiconductors: in a fairly wide frequency range it is described by the 1/<i>f</i> law, and in the presence of an electric field in the low-frequency region a saturation region appears. The temperature dependence of the electron mobility noise parameter in GaAs is computed, which qualitatively and quantitatively agrees with some experimental data on the temperature dependence of the Hooge parameter of low-frequency current noise in <i>n</i>-GaAs.</p>","PeriodicalId":623,"journal":{"name":"Journal of Contemporary Physics (Armenian Academy of Sciences)","volume":"59 4","pages":"426 - 436"},"PeriodicalIF":0.5,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Analysis of Harmonic Signals in Non-Real Time of Moving Targets in Complex Environments Using Higher-Order Statistics in LabVIEW
IF 0.5 4区 物理与天体物理
Journal of Contemporary Physics (Armenian Academy of Sciences) Pub Date : 2025-03-16 DOI: 10.1134/S1068337225700124
A. Hakhoumian, M. Barseghyan, N. Gasparyan, B. Hovhannisyan, E. Sivolenko
{"title":"Analysis of Harmonic Signals in Non-Real Time of Moving Targets in Complex Environments Using Higher-Order Statistics in LabVIEW","authors":"A. Hakhoumian,&nbsp;M. Barseghyan,&nbsp;N. Gasparyan,&nbsp;B. Hovhannisyan,&nbsp;E. Sivolenko","doi":"10.1134/S1068337225700124","DOIUrl":"10.1134/S1068337225700124","url":null,"abstract":"<p>A new method of using bispectral analysis for detecting moving targets is presented. The cepstrum method is used to improve the detection of harmonic frequencies. The method involves reading a file and using an algorithm that finds the desired harmonics in the bispectrum, reducing noise. This targeted approach facilitates tracking and understanding moving targets. The method has been tested in simulations and found to significantly improve target detection and frequency resolution compared to traditional methods of bispectral analysis. This new methodology helps to track moving targets more accurately and efficiently, especially in radar and sonar systems where precise tracking is crucial.</p>","PeriodicalId":623,"journal":{"name":"Journal of Contemporary Physics (Armenian Academy of Sciences)","volume":"59 4","pages":"408 - 412"},"PeriodicalIF":0.5,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Propagation Characteristics of q-Gaussian Laser Beam in Cold Collisionless Plasma
IF 0.5 4区 物理与天体物理
Journal of Contemporary Physics (Armenian Academy of Sciences) Pub Date : 2025-03-16 DOI: 10.1134/S1068337225700203
K. Walia, N. Mehra, S. Pandit
{"title":"Propagation Characteristics of q-Gaussian Laser Beam in Cold Collisionless Plasma","authors":"K. Walia,&nbsp;N. Mehra,&nbsp;S. Pandit","doi":"10.1134/S1068337225700203","DOIUrl":"10.1134/S1068337225700203","url":null,"abstract":"<p>The propagation characteristics of q-Gaussian laser beam in Cold Collisionless plasma are explored in current research work. In Cold Collisionless plasma, the carriers get redistributed away from axial portion due to ponderomotive force. This carrier redistribution leads to production of density gradients thereby causing self-focusing of beam. The Wentzel–Kramers–Brillouin and paraxial approximations are utilized for deriving nonlinear 2nd order differential equation for beam width of the beam. Since, this differential equation can’t be solved analytically. So, numerical solution has been obtained for exploring the variation of beam width of beam against normalized propagation distance. Impact of variation in established parameters of laser and plasma such as beam intensity, beam radius, density of plasma electrons, plasma temperature and q-parameter on behavior of laser beam is also examined.</p>","PeriodicalId":623,"journal":{"name":"Journal of Contemporary Physics (Armenian Academy of Sciences)","volume":"59 4","pages":"378 - 385"},"PeriodicalIF":0.5,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
The Energy Levels of a Shallow Impurity in Monolayer Graphene in a Perpendicular Magnetic Field
IF 0.5 4区 物理与天体物理
Journal of Contemporary Physics (Armenian Academy of Sciences) Pub Date : 2025-03-16 DOI: 10.1134/S1068337225700094
A. A. Avetisyan, A. P. Djotyan
{"title":"The Energy Levels of a Shallow Impurity in Monolayer Graphene in a Perpendicular Magnetic Field","authors":"A. A. Avetisyan,&nbsp;A. P. Djotyan","doi":"10.1134/S1068337225700094","DOIUrl":"10.1134/S1068337225700094","url":null,"abstract":"<p>The energies of the ground 1<i>S</i> and the first three excited levels of 2<i>S</i>, 2<i>P</i><sup>–</sup> and <span>(2{{P}^{ + }})</span>of a shallow impurity in graphene monolayer with an opened energy gap in a perpendicular magnetic field, are studied by a variational approach. The dependences of the energy of impurity levels on magnitude of the magnetic field are obtained for various values of the “thickness” parameter <i>b</i> of “softened” Coulomb potential. The ability to control the position of impurity energies and distance between them in graphene by changing the magnetic field opens possibilities for implementation of new schemes of coherent interaction of laser pulses with graphene systems.</p>","PeriodicalId":623,"journal":{"name":"Journal of Contemporary Physics (Armenian Academy of Sciences)","volume":"59 4","pages":"386 - 390"},"PeriodicalIF":0.5,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Binding Parameters of Mitoxantrone and Ethidium Bromide with A-Form Nucleic Acids Based on Adsorption Isotherms
IF 0.5 4区 物理与天体物理
Journal of Contemporary Physics (Armenian Academy of Sciences) Pub Date : 2025-03-16 DOI: 10.1134/S106833722570015X
V. P. Kalantaryan, R. S. Ghazaryan, Y. S. Babayan, M. A. Parsadanyan
{"title":"Binding Parameters of Mitoxantrone and Ethidium Bromide with A-Form Nucleic Acids Based on Adsorption Isotherms","authors":"V. P. Kalantaryan,&nbsp;R. S. Ghazaryan,&nbsp;Y. S. Babayan,&nbsp;M. A. Parsadanyan","doi":"10.1134/S106833722570015X","DOIUrl":"10.1134/S106833722570015X","url":null,"abstract":"<p>An analysis of adsorption isotherms was carried out based on experimentally obtained data on the binding of the antitumor compound mitoxantrone (MTX) and ethidium bromide (EB) to A-form nucleic acids (NA). The obtained results show that there is selectivity in binding with base pairs of NA. Calculations show that the enthalpy changes due to the binding of MTX and EB to A-form NA (within the experimental error) are almost the same, but the entropy changes upon binding are significantly different. Generalizing the obtained experimental data and comparing them with the literature, it can be concluded that the binding of these compounds to the B-form is stronger compared to the A-form, leading to a more pronounced change in the structure of the double helix of NA.</p>","PeriodicalId":623,"journal":{"name":"Journal of Contemporary Physics (Armenian Academy of Sciences)","volume":"59 4","pages":"404 - 407"},"PeriodicalIF":0.5,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Relations Between some Acoustic and Optical Quantities and their Dependence on the Stoichiometry of the Lithium Niobate Crystal
IF 0.5 4区 物理与天体物理
Journal of Contemporary Physics (Armenian Academy of Sciences) Pub Date : 2025-03-16 DOI: 10.1134/S1068337225700215
A. V. Yeganyan, N. E. Kokanyan, N. E. Babajanyan, E. P. Kokanyan
{"title":"Relations Between some Acoustic and Optical Quantities and their Dependence on the Stoichiometry of the Lithium Niobate Crystal","authors":"A. V. Yeganyan,&nbsp;N. E. Kokanyan,&nbsp;N. E. Babajanyan,&nbsp;E. P. Kokanyan","doi":"10.1134/S1068337225700215","DOIUrl":"10.1134/S1068337225700215","url":null,"abstract":"<p>New relationships that express the relationships between some optical and acoustic quantities and the stoichiometry of the lithium niobate single crystal suitable for rapid estimation have been obtained. It is shown that by determining the damping coefficients of transverse and longitudinal hypersonic waves, it is possible to estimate the refractive indices in the terahertz range with great accuracy and determine the stoichiometric composition of the lithium niobate crystal.</p>","PeriodicalId":623,"journal":{"name":"Journal of Contemporary Physics (Armenian Academy of Sciences)","volume":"59 4","pages":"401 - 403"},"PeriodicalIF":0.5,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Horizontal and Vertical Profiling of the Proton Beam of Cyclotron C18/18 by Vibrating Wire Monitors of Modernized Diagnostic Station
IF 0.5 4区 物理与天体物理
Journal of Contemporary Physics (Armenian Academy of Sciences) Pub Date : 2025-03-16 DOI: 10.1134/S1068337225700082
S. G. Arutunian, A. P. Aprahamian, A. V. Margaryan, L. M. Lazarev, N. M. Manukyan, G. V. Mirzoyan, E. G. Lazareva, R. S. Gevorgyan, A. A. Manukyan, M. Chung
{"title":"Horizontal and Vertical Profiling of the Proton Beam of Cyclotron C18/18 by Vibrating Wire Monitors of Modernized Diagnostic Station","authors":"S. G. Arutunian,&nbsp;A. P. Aprahamian,&nbsp;A. V. Margaryan,&nbsp;L. M. Lazarev,&nbsp;N. M. Manukyan,&nbsp;G. V. Mirzoyan,&nbsp;E. G. Lazareva,&nbsp;R. S. Gevorgyan,&nbsp;A. A. Manukyan,&nbsp;M. Chung","doi":"10.1134/S1068337225700082","DOIUrl":"10.1134/S1068337225700082","url":null,"abstract":"<p>The horizontal and vertical profiles of the proton beam of the cyclotron C18/18 were measured by a modernized diagnostic station based on vibrating wire monitors. Considering the results of the first experiments using monitors with an aperture of 14 mm and superimposed lead screens, monitors with an extended aperture (28 mm) and magnets removed from the beam exposure zone were developed. In addition, the sensors are assembled on a thick metal base that serves as a collimator for the beam. The problems of electromagnetic interference are solved by the fact that the electronic nodes of the station are assembled on the same base. Scanning in the new station is carried out in the same plane, as close as possible to the output flange of the cyclotron (54 mm). New software has been developed that normalizes the profiles by the maximum value. Test measurements of the proton beam profile in the range of the average beam current ~1 μA were carried out.</p>","PeriodicalId":623,"journal":{"name":"Journal of Contemporary Physics (Armenian Academy of Sciences)","volume":"59 4","pages":"359 - 365"},"PeriodicalIF":0.5,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Polarimetric Light-Pulse Atom Interferometer: Two-Level Scheme
IF 0.5 4区 物理与天体物理
Journal of Contemporary Physics (Armenian Academy of Sciences) Pub Date : 2025-03-16 DOI: 10.1134/S1068337225700185
A. Zh. Muradyan
{"title":"Polarimetric Light-Pulse Atom Interferometer: Two-Level Scheme","authors":"A. Zh. Muradyan","doi":"10.1134/S1068337225700185","DOIUrl":"10.1134/S1068337225700185","url":null,"abstract":"<p>A new type of atomic interferometer is proposed, in which the traditional method of measuring the state of an atom is replaced by the technique of polarization spectroscopy using the working substance of a clot of condensate of two-level atoms. As a result, the atomic interferometer is freed from needing the above-mentioned multiple repetitions, while maintaining high sensitivity. The Kapitsa-Dirac resonance diffraction is used to split the translational motion of the atom. Numerical computations to determine the rotated component of the probing field show that the ratio of the output signal to the input signal under normal conditions in a specialized laser physics laboratory using a clot of atomic condensate of alkali metals with a concentration of <span>({{10}^{{11}}})</span> cm<sup>–3</sup> and linear dimensions of the order of 1 μm as the working substance reaches quite respectable values.</p>","PeriodicalId":623,"journal":{"name":"Journal of Contemporary Physics (Armenian Academy of Sciences)","volume":"59 4","pages":"371 - 377"},"PeriodicalIF":0.5,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Response Latencies of Visually Sensitive Neurons in Area 21a of the Cortex
IF 0.5 4区 物理与天体物理
Journal of Contemporary Physics (Armenian Academy of Sciences) Pub Date : 2025-03-16 DOI: 10.1134/S1068337225700173
D. K. Khachvankyan, A. A. Meliksetyan, V. V. Nalbandyan
{"title":"Response Latencies of Visually Sensitive Neurons in Area 21a of the Cortex","authors":"D. K. Khachvankyan,&nbsp;A. A. Meliksetyan,&nbsp;V. V. Nalbandyan","doi":"10.1134/S1068337225700173","DOIUrl":"10.1134/S1068337225700173","url":null,"abstract":"<p>The paper presents the results of a study on the duration of latent periods (LP) of responses from single neurons in region 21a after their receptive fields (RF) are triggered by stationary flashing visual stimuli. Neurons exhibiting only ON or OFF responses demonstrate markedly reduced fluctuations in LP duration, and the mean LP duration in these neurons is much lower compared to those with ON-OFF responses. A reduced fluctuation in LP duration was noted in neurons exhibiting a tonic response pattern, which also displayed the shortest average LP duration. The most significant variations in LP durations and the highest average values were seen in ON–OFF neurons exhibiting a phasic response pattern. In only one-third of the examined neurons, the length of LP remains constant across the whole RF area; in the majority of neurons, it fluctuates based on the stimulus’s location inside the RF. The disparity in LP duration within a single RF can attain a factor of three or greater. It was also determined that the majority of neurons exhibit a significant degree of independence in the variations of LP ON and OFF components of ON–OFF responses. The acquired results suggest that the majority of RF neurons 21a area possess not only a complicated spatial organization but also an inhomogeneous discrete temporal structure.</p>","PeriodicalId":623,"journal":{"name":"Journal of Contemporary Physics (Armenian Academy of Sciences)","volume":"59 4","pages":"413 - 419"},"PeriodicalIF":0.5,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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