Petr Stepanov

Phone:

+1 (419) 496-8602

Email:

stepanovps@gmail.com

Current address:

2270 NW Savier St, Portland, OR 97210, United States
Willing to relocate.

Objective

BGSU Ph.D. graduate with expertise in gamma spectroscopy, positron annihilation spectroscopy, microscopy, and nuclear physics. Strong background in computational techniques, desktop software development and web applications. More than five years in user interface and user experience design.

• Seeking a software development position in the industry.
• Willing to join a computational sciences department at a National Lab.

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🗽 Permanent resident authorized to work in the USA.

Computer skills

🛠️ Basics.

Git, Terminal, SSH, BASH scripting. Jira.

🎨 UI/UX design.

Figma, Sketch, Adobe Photoshop, Illustrator, Blender.

🖥️ Desktop development.

C/C++ and Qt, compiling from source (gcc, GNU makefiles). Eclipse IDE.

🖲️ Frontend.

HTML, CSS (SASS), Bootstrap, responsive web design, JavaScript and jQuery, npm, gulp, VS Code.

🕳️ Backend.

Node.js, EJS.

📱 iOS development.

Swift, xCode. User interface development with UiKit and storyboards.

📊 Scientific tools.

High-Performance Computing (HPC), Python, CERN ROOT, Geant4, Wolfram Mathematica, Gnuplot, Origin.

🖋 Markup.

LaTeX, MS Office Suite.

Material research skills

Characterization facilities. Positron Lifetime and Doppler Broadening Annihilation Spectroscopy (PALS, DBAR). Atom Probe Tomography (ATP). Scanning Electron Microscopy (SEM). Transmission electron microscopy (TEM). Atomic Force Microscopy (AFM). UV-VIS Spectroscopy. Fourier Transform Infrared Spectroscopy (FTIR).

Materials processing. High-temperature annealing. Wet chemical etching. Electrical Contact Fabrication. Sample polishing.

Work experience

• 

  Research Scientist

  Thomas Jefferson National Accelerator Facility
  • Newport News, VA, USA

  Jul 2020 - Current
  • Coded a Geant4-based sumulation for studying the optimal light guide length (range 0-10 cm) for the EM calorimeter used in the Electron-Ion-Collider (EIC) project. Link to GitHub.
  • Used Machine Learning (ML) techniques to perform binary classification of thousands of signals from a data acquisition (DAQ) setup. Link to GitHub].
  • Applied CERN ROOT framework (C++) to perform statistical analysis of a significant amount (over 100 GB) of the raw experimental data of the Kaon LT experiment at JLab. Link to GitHub.
  • Utilized SLURM functionality on the JLab High-Performance Computing (HPC) environment to execute series of the simulations in parallel. This reduced the wall time by more than 10 times.
  • Proposed and implemented RAMDisk functionality in the development environment. This led to an over 60% increase in source code indexing time.
  • Replaced proprietary MS Windows-based data acquisition (DAQ) system with an open-source solution. This eliminated random crashes during continuous acquisition.
  • Active collaborator of the Pion LT project. Committed more than 50 shifts performing Target Operator and Shift Leader duties in the experimental Hall C counting room.
• 

  Postdoctoral Researcher

  Catholic University of America
  • Washington, DC, USA

  Jul 2020 - Current
  • Programmed a Geant-4 computer simulation (C++, CMake, Eclipse IDE, gdb) to study performance of a novel scintillation material for EIC, Brookhaven National Lab. Link to GitHub.
  • Visualized energy deposition profiles and calculated energy resolutions for variety of detector assemblies.
  • Teaching experience: mentoring students within a 3-month Research Experiences for Undergraduates (REU) program at the Physics Department at CUA. Giving talks and presentations about Linux Terminal, and supercomputer environment.
  • Enhanced debugging of the core library source code lead to opening more than 10 bug reports on the ROOT (C++) forum.
• 

  Freelance UI/UX Designer and Frontend Developer

  Remote Positions

  Sept 2014 - Current
  • Built an online e-commerce store Sticker Store LLC with static website generator (Hexo, Snipcart, Bootstrap, SASS, EJS, Node.js).
  • Improved the Google PageSpeed Insights metrics (CLS, LCP) up to 97%.
  • Created a recursive script to export over 300 products from the YAML file to Google Merchant.
  • Optimized SEO. The project reached over 1400 organic monthly users.
  • Made iOS application (Swift, UIkit, storyboards) for the We.Team messenger (more than 3k monthly downloads in AppStore). Participated in cloud-based messenger development with enhanced file sharing capabilities (HTML, React JS, SASS).
  • Migrated the landing page for Sweetbridge company from WordPress to Jekyll static site generator (Ruby, CSS). This resulted in a 70% improvement in the page load time.
  • Developed the front-end part (Angular.js, HTML, LESS) for Lili Social network.
  • Assisted with the front-end styling and animations for the iOS mobile application (Ionic).
  • Enabled SEO crawling of over 1000 Angular.js pages with Google bot.
  • Web design.
  • Designed logos, UI/UX prototypes (Figma, Sketch, Illustrator) and branding identity for over 10 different companies.
  • Converted numerous design assets and mockups into responsive HTML and CSS (Bootstrap).
  • Mocked up and integrated dozens of cross-browser responsive email templates.
• 

  Research Assistant, Software Developer

  Center for Photochemical Sciences
  • Bowling Green, OH, USA

  Sept 2014 - May 2020
  • Applied ROOT C++ libraries to write four GUI open-source software for scientific data interpretation.
  • GitHub repositories contain over 10k lines of code in total: SW Calculator, TLIST Processor, RooPositron, LuminApp.
  • Technologies used: CMake, C++, ROOT, Fox GUI, and RooFit libraries. Java and Swing.
  • Extended default ROOT GUI library (Qt-based) to support the MVP design pattern.
  • Wrote a GUI application LuminApp (Java, Swing) to parse and merge time-stamped data from optical spectrometer and thermometer. This increased data processing time by two orders of magnitude.
  • Developed static website (Hexo, Gulp, Bootstrap) and visual identity for the SelimLab research group. The website has a 99% Google performance rank and features 700 ms time to interactive metrics.
  • Maintained local Apache HTTP server physics.bgsu.edu hosting over 10 websites at the BGSU.
  • Created website for the ICPA-18 international conference with registration (over 150 users) and payment system workflow (WordPress, PHP, Recurly.js), and landing pages for events.
• 

  Web Designer, Frontend Web Developer

  Gridnine Systems
  • Moscow, Russia

  Apr 2011 - Aug 2014
  • Responsible for the front-end development of the ATH American Express – the largest travel management company in Russia (JavaScript, Backbone.js, and RequireJS). Increased the front-end load time by over 30%.
  • Utilized Google Web Toolkit (GWT) Model-View-Presenter (MVP) framework to develop frontend for Otixo cloud file integrator (JavaScript, CSS, responsive design).
  • Implemented image processing servlets on the backend to generate banners for five different social networks (PHP, ImageMagic).
  • Prototyping conceptual wireframes and UI/UX mockups for numerous web applications (Adobe Creative Suite).
• 

  Computer Science Teacher

  Yunium Educational Center at MIPT
  • Moscow, Russia

  Oct 2009 - May 2011

  Provided instructions and guidance to middle school students on the following computer courses:

  • C and C++ programming.
  • Markup on the web (HTML, CSS).
  • Raster graphics and Adobe Photoshop.
  • Modelling in 3D Studio Max.
• 

  Research Scientist

  Institute for Theoretical and Experimental Physics (ITEP)
  • Moscow, Russia

  Sept 2008 - Apr 2011
  • Application of Lositron Annihilation Lifetime Spectroscopy (PALS) for studying the radioactive-induced defects in steels.
  • Applied CERN ROOT libraries for fitting and analysis of experimental data.
  • Monte-Carlo particle simulations with Fortran 95.
  • Installed step motors to rotate the sample inside the Tomographic Atom Probe chamber. Developed the software to support the rotation.
  • Improved the CAMECA software to increase the accuracy of data reconstruction for the Tomographic Atom Probe (MSVC).

Education

• 

  Bowling Green State University

  Aug 2014 - May 2020

  Bowling Green, OH, USA

  Ph.D. Doctor of Philosophy in photochemical sciences. Occupation: materials science, interaction of ionizing radiation with matter, radiation defects in solids, radiation chemistry, gamma-spectroscopy, positron annihilation spectroscopy.

  Dissertation topic: New developments in positron annihilation spectroscopy techniques: from experimental setups to advanced processing software. Download manuscript with corrections.

  Under the guidance of Dr. Selim I have successfully assembled and maintained Doppler and lifetime positron spectrometers from ORTEC and Canberra fast-timing units. My research was aimed at the application of Doppler and lifetime positron spectroscopy techniques to study the following effects in materials:

  • Defects and grain sizes in solids.
  • Kinetics of positrons and positronium atoms in nano-powders.
  • Oxidation and ortho-para conversion of positronium atoms in liquids.

  My research required a good understanding of single-photon counting techniques with HPGe and scintillation-based detector systems. I manufactured sources of positron radiation and was responsible for inventorying the radioactive materials.

  I have developed several open-source desktop GUI software solutions for fitting and interpreting the raw positron experimental spectra. Software is written in C++, it extensively utilizes the CERN ROOT and RooFit frameworks.

  Additionally, I created was responsible for creating websites for the research groups and international conferences.

• 

  National Research Nuclear University

  Sept 2004 - Feb 2011

  Moscow, Russia

  B.S. M.S. Bachelor and Master of Science in solid state physics. Monte-Carlo particle simulations with Fortran 95. Maintaining software for CAMECA tomographic atom probe (MSVC). Application of CERN ROOT libraries for fitting and analysis of experimental data.

  Thesis topic: Radiation defect studies of nuclear power plant vessel steels by means of positron lifetime annihilation spectroscopy.

Relevant courses

• 

  Ohio Supercomputer Workshop

  Jan 2017

  Bowling Green, OH, USA

  Hands-on sessions on supercomputer operation. Got familiar with the newest developments in the supercomputer services: network use with SSH, job control with SLURM scripts, RedHat and CentOS operating systems, CMake compiling platform, parallel environments and more.

• 

  British Higher School of Art and Design

  Dec 2011 - Feb 2012

  Moscow, Russia

  Three-month intensive: graphical design and visual communications.

  Introduction to the major tricks and instruments of visual communication; learning fundamental rules of illustrations, typography, fonts, and lettering. Intensives on brand identity, graphical language, and advertising campaigns.

Web Projects

Scientific software

During my post-doctorate researcher role at the CUA I was responsible for carrying out Monte Carlo particle simulations in High Energy Physics (HEP). The gold standard simulation toolkit in physics is Geant4. On the other hand, ROOT framework is utilized for the data analysis and processing. Geant4 and ROOT are massive C++ libraries. Delivery of the production-ready software that incorporates these frameworks requires a proper project setup on a local computer.

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I utilized Geant4 framework to collaborate on the Electron-Ion Detector (EIC) project. Additionally, I developed a Geant4-based simulation for studying the performance of scintillation materials. The program reconstructs energy deposition, light yield, and detector response.

My PhD research in physics at BGSU was interdisciplinary with computer science. I developed several desktop software products for data analysis and experimental spectra interpretation. I utilized and contributed to the development of the CERN ROOT framework. ROOT ecosystem offers a variety of tools for histogram manipulation, plotting, fitting, and data storage. The framework allows for building standalone graphical user interface (GUI) software.

Recent publications

• Revealing the Structure of Light Pseudoscalar Mesons at the Electron-Ion Collider.

  Arrington, J.; Gayoso, C. A.; Barry, P. C.; Berdnikov, V.; Binosi, D.; Chang, L.; Diefenthaler, M.; Ding, M.; Ent, R.; Frederico, T.; Furletova, Y.; Hobbs, T. J.; Horn, T.; Huber, G. M.; Kay, S. J. D.; Keppel, C.; Lin, H.-W.; Mezrag, C.; Montgomery, R.; Pegg, I. L.; Raya, K.; Reimer, P.; Richards, D. G.; Roberts, C. D.; Rodríguez-Quintero, J.; Romanov, D.; Salmè, G.; Sato, N.; Segovia, J.; Stepanov, P.; Tadepalli, A. S.; Trotta, R. L. J. Phys. G: Nucl. Part. Phys. 2021, 48 (7), 075106. DOI: 10.1088/1361-6471/abf5c3.

• Interaction of positronium with dissolved oxygen in liquids.

  Stepanov, P. S.; Selim, F. A.; Stepanov, S. V.; Bokov, A. V.; Ilyukhina, O. V.; Duplâtre, G.; Byakov, V. M. Physical Chemistry Chemical Physics 2020, DOI: 10.1039/C9CP06105C

• A Model for Joint Processing of LT and CDB Spectra of Dielectric Nano-sized Powders.

  Stepanov, P. S.; Selim, F. A.; Stepanov, S. V.; Byakov, V. M. AIP Conference Proceedings 2019, 2182 (1), 040004. DOI: 10.1063/1.5135836

• Positron and positronium in Al₂O nanopowders.

  Stepanov, P. S.; Selim, F. A.; Stepanov, S. V.; Byakov, V. M. AIP Conference Proceedings 2019, 2182 (1), 050008. DOI: 10.1063/1.5135851

• Defects and solarization in YAG transparent ceramics.

  Zhang, L.; Wu, J.; Stepanov, P.; Haseman, M.; Zhou, T.; Winarski, D.; Saadatkia, P.; Agarwal, S.; Selim, F. A.; Yang, H.; et al. Photonics Research 2019, 7 (5), 549-557 DOI: 10.1364/prj.7.000549

• Photoconductivity of bulk SrTiO3 single crystals at room temperature.

  Saadatkia, P.; Stepanov, P.; Selim, F. A. Materials Research Express 2018, 5 (1), 016202 DOI: 10.1088/2053-1591/aaa094

• Track Effects in Positronium Formation.

  Stepanov, S.; Byakov, V.; Duplâtre, G.; Stepanov, P.; Bokov, A. Acta Physica Polonica A 2017, 132 (5), 1461-1466 DOI: 10.12693/APhysPolA.132.1461

• Developing new routine for processing two-dimensional coincidence doppler energy spectra and evaluation of electron subsystem properties in metals.

  Stepanov, P.; Stepanov, S.; Byakov, V.; Selim, F. Acta Physica Polonica A 2017, 132 (5), 1628-1633 DOI: 10.12693/APhysPolA.132.1628

• ZnO Luminescence and scintillation studied via photoexcitation, X-ray excitation, and gamma-induced positron spectroscopy.

  Ji, J.; Colosimo, A. M.; Anwand, W.; Boatner, L. A.; Wagner, A.; Stepanov, P. S.; Trinh, T. T.; Liedke, M. O.; Krause-Rehberg, R.; Cowan, T. E.; et al. Scientific reports 2016, 6 (1), 31238 DOI: 10.1038/srep31238

• Premelting as studied by positron annihilation and emission Mössbauer spectroscopies.

  Stepanov, S. V.; Byakov, V. M.; Zvezhinskiy, D. S.; Duplâtre, G.; Dubov, L. Y.; Stepanov, P. S.; Perfiliev, Y. D.; Kulikov, L. A. Journal of Physics: Conference Series 2016, 674, 012018 DOI: 10.1088/1742-6596/674/1/012018

• Scintillation of Un-doped ZnO Single Crystals.

  Colosimo, A. M.; Ji, J.; Stepanov, P. S.; Boatner, L. A.; Selim, F. A MRS Advances 2016, 1 (2), 121-126 DOI: 10.1557/adv.2015.60

• Early processes in positron and positronium chemistry: possible scavenging of epithermal e by nitrate ion in aqueous solutions.

  Stepanov, S. V.; Byakov, V. M.; Duplâtre, G.; Zvezhinskiy, D. S.; Stepanov, P. S.; Zaluzhnyi, A. G. Journal of Physics: Conference Series 2015, 618, 012003 DOI: 10.1088/1742-6596/618/1/012003

• The use of positron spectroscopy for revealing the nanosized structures in liquid mixtures. Identification of n-propanol nanoagglomerates in aqueous solutions.

  Stepanov, P. S.; Byakov, V. M.; Zaluzhnyi, A. G. Russian Journal of Physical Chemistry A 2014, 88 (4), 685-690 DOI: 10.1134/s003602441404027x

View more publications

Conferences

• 18th International Conference on Positron Annihilation (ICPA-18)

  @Orlando, FL, USA

  Aug 2018

  Oral talk “Positions and Ps in Al2O3 Nanopowders”.

• International Workshop on Physics with Positrons (JPos17)

  @Jefferson Lab, Newport News, VA, USA

  Sept 2017

  Poster “A routine of background subtraction from two-dimensional Doppler broadened spectra”.

• 12th International Workshop on Positron and Positronium Chemistry (PPC12)

  @Maria Curie-Sklodowska University, Lublin, Poland

  Aug 2017

  Poster “Developing new routine for processing two-dimensional coincidence Doppler energy spectra”.

• Ohio Photochemical Society Meeting (Oops)

  @Maumee Bay Lodge & Conference Center, Maumee, OH, USA

  May 2017

  Poster “Developing new routine for background subtraction in two-dimensional coincidence Doppler broadening spectroscopy”.

• 58th Electronic Materials Conference (EMC)

  @University of Delaware, Newark, DE, USA

  Jun 2016

  Oral talk “High-Sensitivity Measurements of Defects in ZnO by Means of Digital Coincidence Doppler Broadening of Positron Annihilation Spectroscopy”.

• Annual Spring Meeting of the APS Ohio-Region

  @University of Delaware, Newark, DE, USA

  Apr 2016

  Oral talk “Identification of chemical environment of defects in ZnO by means of digital coincidence Doppler broadening of positron annihilation radiation”.

• Ohio Inorganic Weekend

  @Bowling Green State University, OH, USA

  Nov 2015

  Poster “Approaching Structural Defect Characterization and their Chemical Identification by Means of Coincidence Doppler Broadening of Annihilation Radiation”.

• 41st Polish Seminar on Positron Annihilation (PSPA-13)

  @Maria Curie-Sklodowska University, Lublin, Poland

  Sep 2013

  Oral talk “Application of positron spectroscopy for detection of nanostructures in alcohol―aqueous mixtures”.

Professional networks

• Check out my portfolio on Dribbble.
• Look up some of my code on GitHub.
• Find my professional contacts on Linkedin.
• Get familiar with my scientific carreer on ResearchGate.
• Skim through list of my publications on Google Scholar.

Interests

💻 Linux and open-source software.

• Hosting an open-source project for keyboard remapping on Linux (300+ stars on GitHub).
• Contributing to the C++ open source framework ROOT. Submitted multiple bug reports. Created two shared libraries to facilitate data analysis: CanvasHelper and RootUtils.

🛠 Working on cars and motorcycles.

• Volunteered repairing cars for students on Bowling Green, OH.
• Member of a non-profit car garage "Econoline Underground" in Oregon City, OR.