Academic literature on the topic 'Relativistic processe'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Relativistic processe.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Relativistic processe"

1

Supriadi, Bambang, Singgih Bektiarso, Arita Fajar Damasari, Putri Indah Ramadhani, Trias Rizqi Febrianti, and Lubna Lubna. "RESPON SISWA TERHADAP METODE PYTHAGORAS SEBAGAI ALTERNATIF PENYELESAIAN SOAL ENERGI RELATIVISTIK." ORBITA: Jurnal Kajian, Inovasi dan Aplikasi Pendidikan Fisika 8, no. 1 (2022): 128. http://dx.doi.org/10.31764/orbita.v8i1.8582.

Full text
Abstract:
ABSTRAKTeori relativitas khusus merupakan teori yang dikembangkan Albert Einstein berkaitan kerelativitasan ruang dan waktu. Penelitian bertujuan mengetahui respon siswa Sekolah Menengah Atas terhadap penyelesaian soal energi relativistik dengan metode phytagoras. Metode penelitian adalah metode penelitian survei dengan subjek penelitian siswa kelas XI MIPA 1 SMA Muhammadiyah 3 Jember tahun ajaran 2021/2022 berjumlah 28 orang. Penelitian merupakan penelitian pengembangan dari peneliti sebelumnya. Teknik pengambilan sampel pada penelitian ini yaitu menggunakan sampling jenuh menggunakan angket
APA, Harvard, Vancouver, ISO, and other styles
2

Whelan, Colm T., J. Rasch, H. R. J. Walters, S. Keller, H. Ast, and R. M. Dreizler. "Inner shell (e, 2e) processes." Canadian Journal of Physics 74, no. 11-12 (1996): 804–10. http://dx.doi.org/10.1139/p96-114.

Full text
Abstract:
The great advantage of coincidence measurements is that by suitable choice of the kinematical and geometrical arrangement one may probe delicate physical effects that would be swamped in less differential experiments. The calculation of the triple-differential cross section for the inner shell ionization of high-Z elements at relativistic energies presents a serious challenge to theory. Relativistic effects enter in both the kinematics and the nature of the target, and the large atom exerts a strong distorting influence. We consider such processes in a range of geometries and kinematics. We re
APA, Harvard, Vancouver, ISO, and other styles
3

Nakel, W. "Relativistic (e,2e) processes." Physics Reports 315, no. 6 (1999): 409–71. http://dx.doi.org/10.1016/s0370-1573(98)00129-x.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

REIMER, ANITA. "HADRON-INITIATED EMISSION PROCESSES IN BLAZAR JETS." International Journal of Modern Physics D 18, no. 10 (2009): 1511–15. http://dx.doi.org/10.1142/s021827180901559x.

Full text
Abstract:
Despite many advances in AGN physics, observationally as well as theoretically, the relativistic matter composition of extragalactic jets remains concealed. In contrast to the so called leptonic AGN emission models, hadronic models consider relativistic protons to be present in those sources, in addition to the relativistic electrons and positrons, and possibly cold material. Here I briefly discuss most processes that are commonly believed to characterize the so-called hadronic AGN emission models, and these include leptonic as well as hadronic processes. As an application predictions for the
APA, Harvard, Vancouver, ISO, and other styles
5

Glushkov, A. V., V. B. Ternovsky, V. V. Buyadzhi, P. A. Zaichko, and L. V. Nikola. "ADVANCED RELATIVISTIC ENERGY APPROACH TO RADIATION DECAY PROCESSES IN ATOMIC SYSTEMS." Photoelectronics, no. 24 (December 28, 2015): 11–22. http://dx.doi.org/10.18524/0235-2435.2015.24.157999.

Full text
Abstract:
We consider the fundamental aspects of the advanced generalized energy approach to relativistic calculation of the radiative decay (transitions) probabilities in heavy neutral atomic systems and multicharged ions. The approach is based on the Gell-Mann and Low S-matrix formalism and the relativistic many-body perturbation theory (PT) with using the optimized one-quasiparticle representation and an accurate account of the relativistic and correlation. In relativistic case the Gell-Mann and Low formula expresses an energy shift through the electrodynamical scattering matrix including the interac
APA, Harvard, Vancouver, ISO, and other styles
6

VILA, GABRIELA S. "RADIATIVE PROCESSES IN JETS." International Journal of Modern Physics D 19, no. 06 (2010): 659–69. http://dx.doi.org/10.1142/s0218271810016841.

Full text
Abstract:
Relativistic jets and collimated outflows are ubiquitous phenomena in astrophysical settings, from young stellar objects up to Active Galactic Nuclei. The observed emission from some of these jets can cover the whole electromagnetic spectrum, from radio to gamma-rays. The relevant features of the spectral energy distributions depend on the nature of the source and on the characteristics of the surrounding environment. Here the author reviews the main physical processes that command the interactions between populations of relativistic particles locally accelerated in the jets, with matter, radi
APA, Harvard, Vancouver, ISO, and other styles
7

Enßlin, Torsten A., and Christoph Pfrommer. "Particle acceleration processes in the cosmic large-scale structure." Proceedings of the International Astronomical Union 2, no. 14 (2006): 372–73. http://dx.doi.org/10.1017/s1743921307011040.

Full text
Abstract:
AbstractThe energetic shock waves associated with the violent large-scale structure formation process are able to accelerate relativistic electrons and protons. The induced non-thermal emission, especially at long radio wavelength, provides a fascinating perspective into structure formation, the relativistic Universe, and cosmic magnetic fields.
APA, Harvard, Vancouver, ISO, and other styles
8

Hsiao, Ju-Tang, Hsiao-Ling Sun, Sheng-Fang Lin, and Keh-Ning Huang. "Photoionization Processes of the Single-Ionized Boron." Journal of Atomic, Molecular, and Optical Physics 2011 (March 13, 2011): 1–9. http://dx.doi.org/10.1155/2011/452026.

Full text
Abstract:
The relativistic calculations of the cross-section σ, the angular-distribution parameter β, and spin-polarization parameters {ξ,η,ζ} of photoelectrons using the multiconfiguration relativistic random-phase approximation theory for the photoionization of the B+ ion are presented. Precise energies and widths of all five Rydberg series of doublyexcited states (2pns)1P1o, (2pns)3P1o, (2pnd)1P1o, (2pnd)3P1o, and (2pnd)3D1o are determined. Our predictions are in very close agreement with experiments and are consistent with other calculations.
APA, Harvard, Vancouver, ISO, and other styles
9

TSUPKO, OLEG YU. "MAGNETO-PLASMA PROCESSES IN RELATIVISTIC ASTROPHYSICS: MODERN DEVELOPMENTS." International Journal of Modern Physics D 22, no. 07 (2013): 1330016. http://dx.doi.org/10.1142/s0218271813300164.

Full text
Abstract:
This contribution is a review of some talks presented at the session "Magneto-Plasma Processes in Relativistic Astrophysics" of the Thirteenth Marcel Grossmann Meeting MG13. We discuss the modern developments of relativistic astrophysics, connected with presence of plasma and magnetic fields. The influence of magneto-plasma processes on the structure of the compact objects and accretion processes is considered. We also discuss a crucial role of magnetic field for the mechanism of core-collapse supernova explosions. Gravitational lensing in plasma is also considered.
APA, Harvard, Vancouver, ISO, and other styles
10

Fasshauer, Elke, Přemysl Kolorenč, and Markus Pernpointner. "Relativistic decay widths of autoionization processes: The relativistic FanoADC-Stieltjes method." Journal of Chemical Physics 142, no. 14 (2015): 144106. http://dx.doi.org/10.1063/1.4917255.

Full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Relativistic processe"

1

Glass, John T. "Relativistic ion-atom collision processes." Thesis, Queen's University Belfast, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282153.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Dunkel, Jörn. "Relativistic Brownian motion and diffusion processes." kostenfrei, 2008. http://d-nb.info/991318757/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Jaroschek, Claus. "Critical Kinetic Plasma Processes In Relativistic Astrophysics." Diss., lmu, 2005. http://nbn-resolving.de/urn:nbn:de:bvb:19-46601.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Jamil, Omar. "A theoretical study of relativistic jets and accretion processes." Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/161189/.

Full text
Abstract:
The following work explores different aspects of the disc:jet connection in X-ray binaries. There is a detailed description of a new jet model (iShocks) that is used, firstly, to address the re-energization problem in the conical jet geometries. The adiabatic energy losses suffered by conical jets are successfully countered to reproduce the canonical flat/inverted synchrotron spectrum associated with compact radio jets. The iShocks model uses discrete packets of plasma, or shells, to simulate a jet. The shell collisions give rise to the shocks that are used to re-energize the emitting electron
APA, Harvard, Vancouver, ISO, and other styles
5

Postavaru, Octavian [Verfasser]. "Strong-field relativistic processes in highly charged ions / Octavian Postavaru." Heidelberg : Universitätsbibliothek Heidelberg, 2010. http://d-nb.info/1024909743/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Chen, Guo-Xin. "Relativistic close coupling calculations for fundamental atomic processes in astrophysics." Columbus, Ohio : Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1078938510.

Full text
Abstract:
Thesis (Ph. D.)--Ohio State University, 2004.<br>Title from first page of PDF file. Document formatted into pages; contains xxvi, 249 p.; also includes graphics (some col.). Includes abstract and vita. Advisor: Anil K. Pradhan, Dept. of Astronomy. Includes bibliographical references (p. 237-249).
APA, Harvard, Vancouver, ISO, and other styles
7

Melzani, Mickaël. "Reconnexion magnétique non-collisionelle dans les plasmas relativistes et simulations particle-in-cell." Thesis, Lyon, École normale supérieure, 2014. http://www.theses.fr/2014ENSL0946/document.

Full text
Abstract:
L'objectif de cette thèse est l'étude de la reconnexion magnétique dans les plasmas non-collisionels et relativistes. De tels plasmas sont présents dans divers objets astrophysiques (MQs, AGNs, GRBs...), où la reconnexion pourrait expliquer la production de particules et de radiation de haute énergie, un chauffage, ou des jets. Une compréhension fondamentale de la reconnexion n'est cependant toujours pas acquise, en particulier dans les plasmas relativistes ion-électron. Nous présentons d'abord les bases de la reconnexion magnétique. Nous démontrons des résultats particuliers à la physique des
APA, Harvard, Vancouver, ISO, and other styles
8

Tardif, Camille. "Etude infinitésimale et asymptotique de certains flots stochastiques relativistes." Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00703181.

Full text
Abstract:
Nous étudions certains processus de Lévy à valeurs dans les groupes d'isométries respectifs des espace-temps de Minkowski, de De Sitter et de Anti-De-Sitter. Le groupe d'isométries est vu comme le fibré des repères de l'espace-temps et les processus de Lévy considérés se projettent sur le fibré unitaire en un processus markovien relativiste ; c'est-à-dire que les trajectoires dans l'espace-temps sont de genre temps et que le générateur est invariant par les isométries. Dans la première partie nous adaptons pour les diffusions hypoelliptiques générales un résultat de Ben Arous et Gradinaru conc
APA, Harvard, Vancouver, ISO, and other styles
9

Fitoussi, Thomas. "Les cascades électromagnétiques cosmologiques comme sondes du milieu intergalactique." Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30235/document.

Full text
Abstract:
Cette thèse vise à étudier le phénomène dit de " cascades électromagnétiques cosmologiques ". Ces cascades sont typiquement générées dans le milieu intergalactique par l'absorption de rayons gamma sur les photons du fond optique / UV et par la production de paires électron / positron associés. Ces leptons eux-mêmes interagissent avec les photons du fond diffus cosmologique via diffusion inverse Compton pour produire de nouveaux rayons gamma qui eux même peuvent s'annihiler, générant à partir d'un unique photon primaire toute une gerbe de photons et de particules secondaires. D'un point de vue
APA, Harvard, Vancouver, ISO, and other styles
10

Lundman, Christoffer. "Photospheric emission from structured, relativistic jets : applications to gamma-ray burst spectra and polarization." Doctoral thesis, KTH, Partikel- och astropartikelfysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-136178.

Full text
Abstract:
The radiative mechanism responsible for the prompt gamma-ray burst (GRB) emission remains elusive. For the last decade, optically thin synchrotron emission from shocks internal to the GRB jet appeared to be the most plausible explanation. However, the synchrotron interpretation is incompatible with a significant fraction of GRB observations, highlighting the need for new ideas. In this thesis, it is shown that the narrow, dominating component of the prompt emission from the bright GRB090902B is initially consistent only with emission released at the optically thick jet photosphere. However, th
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Relativistic processe"

1

Bertulani, Carlos A. Electromagnetic processes in relativistic heavy ion collisions. Zentralbibliothek der Kernforschungsanlage, 1987.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Becchi, Carlo M., and Giovanni Ridolfi. An introduction to relativistic processes and the standard model of electroweak interactions. Springer Milan, 2006. http://dx.doi.org/10.1007/88-470-0421-7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Becchi, Carlo M., and Giovanni Ridolfi. An Introduction to Relativistic Processes and the Standard Model of Electroweak Interactions. Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-06130-6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Center, Langley Research, ed. Stopping powers and cross sections due to two-photon processes in relativistic nucleus-nucleus collisions. National Aeronautics and Space Administration, Langley Research Center, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Jacob, Andreas. Relativistic Effects in Interatomic Ionization Processes and Formation of Antimatter Ions in Interatomic Attachment Reactions. Springer Fachmedien Wiesbaden, 2024. http://dx.doi.org/10.1007/978-3-658-43891-3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Baikie, Grant. Relativistic Brownian Motion and Diffusion Processes. Independently Published, 2018.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Morawetz, Klaus. Relativistic Transport. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198797241.003.0022.

Full text
Abstract:
The quantum kinetic equations for relativistic baryon-meson systems are derived from Kadanoff and Baym equations. It is shown that the virtual exchange of mesons create an effective Yukawa potential between the nucleons. Binding properties of nuclear matter are discussed and the problem of Coester line is explored which means that only three-particle correlations or relativistic effective masses can describe the binding of nuclear matter correctly. The derived kinetic equations show in-medium processes of scattering and particle creation and destruction which are forbidden for free-scattering.
APA, Harvard, Vancouver, ISO, and other styles
8

Unified Non-Local Relativistic Theory of Transport Processes. Elsevier, 2016. http://dx.doi.org/10.1016/c2016-0-00437-0.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Alexeev, Boris V. Unified Non-Local Relativistic Theory of Transport Processes. Elsevier, 2016.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

Alexeev, Boris V. Unified Non-Local Relativistic Theory of Transport Processes. Elsevier Science & Technology Books, 2016.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "Relativistic processe"

1

Avetissian, Hamlet K. "Induced Nonstationary Transition Process." In Relativistic Nonlinear Electrodynamics. Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-26384-7_6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Nagasawa, Masao. "Relativistic Quantum Particles." In Stochastic Processes in Quantum Physics. Birkhäuser Basel, 2000. http://dx.doi.org/10.1007/978-3-0348-8383-2_7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Avetissian, Hamlet K. "“Relativistic” Nonlinear Electromagnetic Processes in Graphene." In Relativistic Nonlinear Electrodynamics. Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-26384-7_14.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Avetissian, Hamlet K. "Induced Channeling Process in a Crystal." In Relativistic Nonlinear Electrodynamics. Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-26384-7_7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Lindgren, Ingvar. "Dynamical Bound-State Processes." In Relativistic Many-Body Theory. Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-15386-5_13.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Kimball, J. C., and N. Cue. "High-Energy Processes in Crystals: Radiation, Pair Creation, Photon Splitting and Pion Creation." In Relativistic Channeling. Springer US, 1987. http://dx.doi.org/10.1007/978-1-4757-6394-2_22.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Avetissian, Hamlet K. "Quantum Theory of Induced Multiphoton Cherenkov Process." In Relativistic Nonlinear Electrodynamics. Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-26384-7_3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Nagasawa, Masao. "Non-Relativistic Quantum Theory." In Stochastic Processes in Quantum Physics. Birkhäuser Basel, 2000. http://dx.doi.org/10.1007/978-3-0348-8383-2_3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Avetissian, Hamlet K. "Nonlinear Dynamics of Induced Compton and Undulator Processes." In Relativistic Nonlinear Electrodynamics. Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-26384-7_5.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Böttcher, Markus, and Anita Reimer. "Radiation Processes." In Relativistic Jets from Active Galactic Nuclei. Wiley-VCH Verlag GmbH & Co. KGaA, 2012. http://dx.doi.org/10.1002/9783527641741.ch3.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Relativistic processe"

1

Debbasch, F., and C. Chevalier. "Relativistic Stochastic Processes." In NONEQUILIBRIUM STATISTICAL MECHANICS AND NONLINEAR PHYSICS: XV Conference on Nonequilibrium Statistical Mechanics and Nonlinear Physics. AIP, 2007. http://dx.doi.org/10.1063/1.2746722.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Johnson, W. R., M. S. Safronova, and A. Derevianko. "All-order methods in relativistic atomic structure theory." In ATOMIC PROCESSES IN PLASMAS. ASCE, 1998. http://dx.doi.org/10.1063/1.56557.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Zingale, M. "Quenching processes in flame-vortex interactions." In RELATIVISTIC ASTROPHYSICS: 20th Texas Symposium. AIP, 2001. http://dx.doi.org/10.1063/1.1419598.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Yong-Ki Kim. "Relativistic and quantum electrodynamic effects in highly-charged ions." In Atomic processes in plasmas. AIP, 1990. http://dx.doi.org/10.1063/1.39286.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Grant, I. P. "Relativistic atomic structure and electron–atom collisions." In X-ray and inner-shell processes. AIP, 1990. http://dx.doi.org/10.1063/1.39829.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Fontes, Christopher J. "All Overview of Relativistic Distorted-Wave Cross Sections." In ATOMIC PROCESSES IN PLASMAS: 14th APS Topical Conference on Atomic Processes in Plasmas. AIP, 2004. http://dx.doi.org/10.1063/1.1824855.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Debbasch, F. "Relativistic Stochastic Processes: A review." In ALBERT EINSTEIN CENTURY INTERNATIONAL CONFERENCE. AIP, 2006. http://dx.doi.org/10.1063/1.2399614.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Pelletier, Guy. "High Energy Processes in Relativistic Flows." In HIGH ENERGY GAMMA-RAY ASTRONOMY: 2nd International Symposium on High Energy Gamma-Ray Astronomy. AIP, 2005. http://dx.doi.org/10.1063/1.1878395.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Rybicki, George B., and Benjamin C. Bromley. "Spectral line signatures of relativistic disks." In Accretion processes in astrophysical systems: Some like it hot! - eigth astrophysics conference. AIP, 1998. http://dx.doi.org/10.1063/1.55905.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Zirakashvili, V. N., Felix A. Aharonian, Werner Hofmann, and Frank M. Rieger. "Nonthermal processes in supernova remnants." In 25TH TEXAS SYMPOSIUM ON RELATIVISTIC ASTROPHYSICS (TEXAS 2010). AIP, 2011. http://dx.doi.org/10.1063/1.3635833.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Relativistic processe"

1

Соловйов, Володимир Миколайович, and D. N. Chabanenko. Financial crisis phenomena: analysis, simulation and prediction. Econophysic’s approach. Гумбольдт-Клуб Україна, 2009. http://dx.doi.org/10.31812/0564/1138.

Full text
Abstract:
With the beginning of the global financial crisis, which attracts the attention of the international community, the inability of existing methods to predict the events became obvious. Creation, testing, adaptation of the models to the concrete financial market segments for the purpose of monitoring, early prediction, prevention and notification of financial crises is gaining currency nowadays. Econophysics is an interdisciplinary research field, applying theories and methods originally developed by physicists in order to solve problems in economics, usually those including uncertainty or stoch
APA, Harvard, Vancouver, ISO, and other styles
2

Kiv, Arnold E., Olexandr V. Merzlykin, Yevhenii O. Modlo, Pavlo P. Nechypurenko, and Iryna Yu Topolova. The overview of software for computer simulations in profile physics learning. [б. в.], 2019. http://dx.doi.org/10.31812/123456789/3260.

Full text
Abstract:
The paper deals with the possibilities of using specialized (virtual labs and simulators, software for natural process simulation) and general (programming languages and libraries, spreadsheets, CAS) software in school researches. Such software as virtual labs, software for natural process simulation, programming languages and libraries in school researches can be used to simulate phenomena that cannot be learned in a school lab (for example, for modeling a radioactive decay or for demonstrating the states of relativistic mechanics). Also, virtual labs in school practice are usually used in th
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!