14 research outputs found
Accretion of matter and spectra of binary X-ray sources in massive gravity
No full textThe authors G. P. and I. L. thank the Fundacao para a Ciencia e Tecnologia (FCT), Portugal, for the financial support to the Center for Astrophysics and Gravitation-CENTRA, Instituto Superior Tecnico, Universidade de Lisboa, through the Project No. UIDB/00099/2020 and grant No. PTDC/FIS-AST/28920/2017. The author A. R. acknowledges Universidad de Tarapaca, Chile for financial support
The Revisionaries: translation and stylistic analysis of selected passages from A. R. Moxon's novel
No full textThis bachelor thesis focuses on translation of selected chapters from the novel The Revisionaries, written by an American author A. R. Moxon. The translation is performed from English language to Czech language and the chapters were selected based chiefly on their linguistic properties. The first part of this thesis, the theoretical introduction, introduces the reader to translation and the theoretical process of translating. Furthermore, it highlights potential issues a translator can stumble upon whilst translating the mentioned novel. In the practical part, four chapters are translated and displayed in a side-by-side format with the original text. The third part of this thesis scrutinises the Czech translated text on the basis of secondary sources, the bulk of which consists of canonical Czech translation studies. Thus, the aim of this part is to justify the Czech translation and to explain the particular decisions which were made during the translation. Keywords translation, novel, fiction, analysis, Moxon, Revisionarie
Geodesic analysis and black hole shadows on a general non-extremal rotating black hole in five-dimensional gauged supergravity
No full textIn this work, motivated by the fact that higher dimensional theories predict the existence of black holes which differ from their four dimensional counterpart, we analyse the geodesics and black hole shadow cast by a general non-extremal five dimensional black hole. The system under consideration corresponds to the Chong–Cvetič–Lü–Pope (Chong et al., 2005), which has the Myers–Perry black hole as a limit.The author A R. acknowledges DI-VRIEA for financial support through Proyecto Postdoctorado 2019 VRIEA-PUCV. The author G.P. thanks the Fundaçao para a Ciencia e Tecnologia (FCT), Portugal, for the financial support to the Center for Astrophysics and Gravitation-CENTRA, Instituto Superior Tecnico, Universidade de Lisboa, through the Project No. UIDB/00099/2020 and the Project No. PTDC/FIS-AST/28920/2017. P.B. is funded by the Beatriz Galindo contract BEAGAL 18/00207 (Spain)
Thermodynamics of scale-dependent Friedmann equations
No full textIn this work, the role of a time-varying Newton constant under the scale-dependent approach is investigated in the thermodynamics of the Friedman equations. In particular, we show that the extended Friedman equations can be derived either from equilibrium thermodynamics when the non-matter energy momentum tensor is interpreted as a fluid or from non-equilibrium thermodynamics when an entropy production term, which depends on the time-varying Newton constant, is included. Finally, a comparison between black hole and cosmological thermodynamics in the framework of scale-dependent gravity is briefly discussed.P. B. is funded by the Beatriz Galindo contract BEAGAL 18/00207 (Spain). The author A. R. acknowledges DI-VRIEA for financial support through Proyecto Postdoctorado 2019 VRIEA-PUCV
Four dimensional Einstein-power-Maxwell black hole solutions in scale-dependent gravity
No full textIn the present work, we extend and generalize our previous work regarding the scale dependence applied to black holes in the presence of non-linear electrodynamics (Rincón et al., 2017). The starting point for this study is the Einstein-power-Maxwell theory with a vanishing cosmological constant in (3+1) dimensions, assuming a scale dependence of both the gravitational and the electromagnetic coupling. We further examine the corresponding thermodynamic properties and how these quantities experience deviations from their classical counterparts. We solve the effective Einstein’s field equations using the “null energy condition” to obtain analytical solutions. The implications of quantum corrections are also briefly discussed. Finally, we analyze our solutions and compare them to related results in the literature.The author A. R. acknowledges DI-VRIEA for financial support through Proyecto Postdoctorado 2019 VRIEA-PUCV. P. B. is funded by the Beatriz Galindo contract BEAGAL 18/00207 (Spain). The author G. P. thanks the Fundação para a Ciência e Tecnologia (FCT), Portugal, for the financial support to the Center for Astrophysics and Gravitation-CENTRA, Instituto Superior Técnico, Universidade de Lisboa , through the Grant No. UID/FIS/00099/2013
Optical and electrical properties of sol-gel spin coated titanium dioxide thin films
No full textIn this work; TiO2
thin films were deposited on glass and stainless steel substrates by
sol-gel spin coating method. The films deposited on glass were annealed at different
temperatures (Ta) in the range of 200 to 500 0C and that are deposited on steel substrate were
annealed at 800 0C. The optical properties of TiO2 thin films were studied by using UV-VIS
spectroscopy and photoluminescence (PL) spectroscopy. The transmittance on the average was
found to ≥ 80 % and is found to sensitive to Ta
. The PL spectra exhibited the strong emission
band associated with band- to- band transition around 390 nm and the two weak bands at 480
and 510 nm associated to the oxygen defects and surface defects respectively. The currentvoltage
(I-V) characteristics of the Al/TiO2
/steel capacitors were studied and analysed with
application of various current mechanisms. Analysis reveals that the conduction in
Al/TiO2/steel capacitors is governed by Poole-Frenkel mechanism.This work was partially supported by UGC through the Start-up Grant
(F.4-5(59-FRP)/2014(BSR))). The author A R Jayakrishnan acknowledges Central University of
Tamil Nadu (CUTN) for the Ph.D fellowship.info:eu-repo/semantics/publishedVersio
Microstructure tailoring for enhancing the energy storage performance of 0.98[0.6Ba(Zr0.2Ti0.8)O3-0.4(Ba0.7Ca0.3)TiO3]-0.02BiZn1/2Ti1/2O3 ceramic capacitors
No full textIn this work, we introduce a new approach to enhance the energy storage properties of
0.98[0.6Ba(Zr0.2Ti0.8)O3-0.4(Ba0.7Ca0.3)TiO3]-0.02BiZn1/2Ti1/2O3 [BCZT-BZ] ceramic
capacitors via tuning the microstructure through the sintering time. The x-ray diffraction
(XRD) analysis confirmed the formation of BCZT-BZ solid solution without any secondary
phase. It is observed that the rhombohedral and tetragonal phases are co-existing in BCZTBZ
samples sintered at different time periods, except the one with sintering time of 11 hrs,
where the rhombohedral and pseudocubic phases co-exist. The energy dispersive x-ray
spectroscopy (EDS) revealed the presence of the elements constituting the BCZT-BZ
samples. The variation of the grain size with the sintering time is explained based on the
coalescence process and the Ostwald ripening mechanism. A strong correlation was observed
between the ferroelectric properties and the microstructure. The sample sintered for 11 hrs
with pseudocubic nature and small grain size shows a slim P-E loop owing to a high
recoverable energy density (2.61 J/cm3) and a higher efficiency (91 %) at an electric field of
150 kV/cm. The observed recoverable energy density was found 3 to 13 times higher than
that reported for the BCZT bulk ceramics. The findings in the present study suggest that
BCZT-BZ ceramics are attractive materials for the energy storage capacitor applications.The work was supported by (i) DST-SERB, Govt. of India through Grant Nr. ECR/2017/000068 and (ii) UGC through Grant Nr. F.4-5(59-FRP/2014(BSR)). The author A. R. Jayakrishnan is thankful to Central University of Tamil Nadu, India for his Ph.D. fellowship. J. P. B. S. is grateful for the financial support by the Portuguese Foundation for Science and Technology in the framework of the Strategic Funding UID/FIS/04650/2019
