Ștefan Țălu

Prof. Dr. Ștefan Țălu

Research, Development and Innovation Management, Technical University of Cluj-Napoca, Cluj-Napoca, Cluj, Romania
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Research Focus & Metrics

Academic Career Length

67Years (1960-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 September 2015 in Estudios Sociológicos de El Colegio de México
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Journal Article
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DHDavid Harvey
David Harvey
ÉSÉdgar Talledos Sánchez
Édgar Talledos Sánchez
Ciudades rebeldes. Del derecho de la ciudad a la revolución urbana

12 June 2019 in Materials Research Express
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Journal Article
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AKAlireza Grayeli Korpi
Alireza Grayeli Korpi
Ștefan ȚăluȘtefan Țălu
Ștefan Țălu
MBMiroslaw Bramowicz
Miroslaw Bramowicz
AAAli Arman
Ali Arman
SKSławomir Kulesza
Sławomir Kulesza
SGSabavath Gopikishan
Sabavath Gopikishan

1 October 2019 in Journal of Alloys and Compounds
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Journal Article
Closed access
XYXi-Tao Yin
Xi-Tao Yin
WZWen-Dong Zhou
Wen-Dong Zhou
JLJing Li
Jing Li
QWQi Wang
Qi Wang
FWFa-Yu Wu
Fa-Yu Wu
Ștefan ȚăluȘtefan Țălu
Ștefan Țălu

6 January 2023 in Results in Physics
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Journal Article
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LDLaya Dejam
Laya Dejam
SKSlawomir Kulesza
Slawomir Kulesza
JSJamshid Sabbaghzadeh
Jamshid Sabbaghzadeh
AGAtefeh Ghaderi
Atefeh Ghaderi
SSShahram Solaymani
Shahram Solaymani
ASAmir Hossein Sari
Amir Hossein Sari

4 June 2021 in Materials
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NPNikola Papež
Nikola Papež
RDRashid Dallaev
Rashid Dallaev
Ștefan ȚăluȘtefan Țălu
Ștefan Țălu
Jaroslav KastylJaroslav Kastyl
Jaroslav Kastyl
As widely-available silicon solar cells, the development of GaAs-based solar cells has been ongoing for many years. Although cells on the gallium arsenide basis today achieve the highest efficiency of all, they are not very widespread. They have particular specifications that make them attractive, especially for certain areas. Thanks to their durability under challenging conditions, it is possible to operate them in places where other solar cells have already undergone significant degradation. This review summarizes past, present, and future uses of GaAs photovoltaic cells. It examines advances in their development, performance, and various current implementations and modifications.

1 January 2015 in Journal of Nanomaterials
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ESEdgar Sanches
Edgar Sanches
SAScarlat F. Alves
Scarlat F. Alves
JSJuliana C. Soares
Juliana C. Soares
ASArnaldo M. Da Silva
Arnaldo M. Da Silva
CSCristina G. Da Silva
Cristina G. Da Silva
HFHidembergue O. Da Frota
Hidembergue O. Da Frota
Polypyrrole (PPY) powder was chemically synthesized using ferric chloride (FeCl3) and characterized by X‐ray diffraction (XRD), Le Bail Method, Fourier Transform Infrared Spectrometry (FTIR), and Scanning Electron Microscopy (SEM). XRD pattern showed a broad scattering of a semicrystalline structure composed of main broad peaks centered at 2θ = 11.4°, 22.1°, and 43.3°. Crystallinity percentage was estimated by the ratio between the sums of the peak areas to the area of amorphous broad halo due to the amorphous phase and showed that PPY has around 20 (1)%. FTIR analysis allowed assigning characteristic absorption bands in the structure of PPY. SEM showed micrometric particles of varying sizes with morphologies similar to cauliflower. Crystal data (monoclinic, space group P 21/c, a = 7.1499 (2) Å, b = 13.9470 (2) Å, c = 17.3316 (2) Å, α = 90 Å, β = 61.5640 (2) Å and γ = 90 Å) were obtained using the FullProf package program under the conditions of the method proposed by Le Bail. Molecular relaxation was performed using the density functional theory (DFT) and suggests that tetramer polymer chains are arranged along the “c” direction. Average crystallite size was found in the range of 20 (1) Å. A value of 9.33 × 10−9 S/cm was found for PPY conductivity.