News & Highlights
May 9, 2023
Congratulations to our 2023 UNC Physics & Astronomy Graduates!! L-R: Fernando Gonzalez, Evander Espinoza, Harrison Massengale, Sarah Davis, Bobbie Brackett, Kyria Smith, Hope Dannar (not pictured: Abe Granberg).
April 26, 2023
UNC Physics majors Hope Dannar and Evan Garneau presented their work at the 2023 Colorado Space Grant Consortium Meeting in Boulder, CO.
March 21, 2023
Prof. Lazarova's paper has been published in the Astrophysical Journal. In this work, the authors used the Hubble Space Telescope to look at the morphologies of a sample of rare quasars (exhibiting very fast winds) and discovered that they are mostly found in merging galaxies. One possible explanation hints at a connection between galaxy mergers and the triggering of fast accretion onto the central supermassive black holes in galaxies, which in turn may drive fast winds and affect the growth of the galaxy itself.
March 10, 2023
Congratulations to Sarah Davis, the 2023 UNC Physics & Astronomy Acadamic Scholar Award winner! Pictured here with Prof. Charles Kuehn.
January 4, 2023
UNC senior physics major Sarah Davis presented her work on solar eclipses at the American Geophysical Union conference held in Chicago.
April 25, 2022
UNC Physics & Astronomy students presented their work at the 2022 Colorado Space Grant Symposium. Evander Espinoza, Tyler Lawson, Hope Dannar, Sarah Davis, and Adam Ontiveros were joined by Prof. Semak at the meeting at CU Boulder. Hope Dannar won an award for best poster in her category!
April 9, 2022
Prof. Engstrom delivered a presentation on The Physics of Exotic Materials at Loveland Aleworks.
April 7, 2022
UNC Physics & Astronomy majors Sarah Davis, Mitch Dack, Nico Alvarado, Caspian Farrell, and Evander Espinoza presented their work at the 2022 UNC Research Day.
September 25, 2021
Prof. Lazarova led a team of intrepid student volunteers at an Astronomy Family Night held at the Poudre Learning Center. Evander Espinoza, Hope Dannar, Sarah Davis, Adam Ontiveros, and Tyler Lawson joined Dr. Lazarova to share their passion for physics and astronomy with over 70 visitors.
September 7, 2021
Prof. Engstrom has published his latest work on High-resolution single-particle cryo-EM of samples vitrified in boiling nitrogen in the International Union of Crystallography Journal.
August 18, 2021
We would like to welcome the newest member of our department, Dr. Tyler Engstrom.
Prof. Engstrom recently moved to Greeley with his wife Ellie, their daughter-to-be (due the day before classes start!), and their pet rabbit Scout. He studied metallurgical engineering at South Dakota School of Mines & Technology and then received his physics PhD at Penn State. He studies soft matter physics, recently working on how the embryonic brain folds into its characteristic shape, and exploring the relationship between dynamically buckled elastic rods in 3d and quantum mechanics in 1d. Prof. Engstrom is looking forward to teaching PHYS 240/241, getting to know the folks in the department, and getting his research lab set up. Please feel free to drop by Tyler's office to say hello.
May 8, 2021
Congratulations to the Spring 2021 Physics & Astronomy graduates (Chris Cornejo, Maya Davidson, Luc Freiberg, Matt Lester, Zachariah Peters, Hayden Pugh) and our Academic Scholar Award winners (Mitchell Dack, Caspian Farrell, Luc Freiberg, Matt Lester).
April 17, 2021
Congratulations to Maya Davidson for winning best poster at the 2021 Colorado Space Grant Consortium Undergraduate Research Symposium! Maya worked with Dr. Mariana Lazarova to study radio data of quasars.
December 21, 2020
Prof. Lazarova hosted a viewing event for the great conjunction of Jupiter and Saturn. Attendees enjoyed a spectacular view of the giant planets not visible from Earth since 1226, hundreds of years before the invention of the telescope.
November 16, 2020
Prof. Chaloupka presented his latest work on Strong-Field Ionization in Bicircular Laser Fields at the OSA High-Brightness Sources and Light-Driven Interactions Congress held virtually.
August 6, 2020
Prof. Chaloupka published his latest work on the Single and Double Ionization of Helium in Intense Bicircular Laser Fields in the Journal of Physics B: Atomic, Molecular and Optical Physics.
March 14, 2020
Congratulations to the 2020 UNC Physics & Astronomy Academic Scholar Award winners: Tim Carlson, Noah Blair, Soren Clawson (front) BP Reeves, Zach Lakin (back).
March 13, 2020
A collaboration between San Diego State University, the Universidad Autonoma de Baja California, and Prof. Chaloupka of UNC Physics published their work on the Spatial Manipulation of a Supercontinuum Beam for the Study of Vortex Interference Effects in the journal Applied Sciences. The researchers used the laser pulses from an ultrafast oscillator, along with a microstructured optical fiber and a high-resolution, large aperture spatial light modulator to generate supercontinuum optical vortices.
March 2, 2020
Kaitlyn Raub presented her work on determining the shape and structures of galaxies that host quasars at the virtual APS March Meeting. This research was perfomed with Prof. Lazarova.
January 29, 2020
Dr. Charles Kuehn was part of an international team that published the first paper on the asteroseismology of red giant stars using NASA’s TESS spacecraft. Red giants, and many other types of stars, experience starquakes which cause them to pulsate, leading to small changes in their brightness which can be observed. Asteroseismologists use these starquakes to learn about the interior of stars, similar to how seismologists use earthquakes to learn about the interior of the Earth. NASA’s TESS spacecraft was launched in 2018 with goal of surveying the entire sky to look for slight changes in the brightness of stars caused by planets orbiting those stars; it’s careful measurements of the brightness of stars also make it ideal for studying starquakes. Dr. Kuehn and the rest of the team were the first people to use TESS observations to study pulsating red giants and their results indicate that not only is the TESS data good enough for asteroseismology but that in a few years it will allow us to studying the pulsations in about 500,000 red giant stars! Their results were published in The Astrophysical Journal Letters.
January 4, 2020
An article by Prof. Semak of Physics & Astronomy, his student Jeremiah Schwartz, and Prof. Heise of Sport & Exercise Science on Examining Human Unipedal Quiet Stance: Characterizing Control Through Jerk has been published in the journal Computational and Mathematical Methods in Medicine.
December 12, 2019
A new article on the Acceleration of Coronal Mass Ejection Plasma in the Low Corona as Measured by the Citizen CATE Experiment was published in the Publications of the Astronomical Society of the Pacific. UNC Astronomy Professor Mariana Lazarova is a member of the CATE team.
December 5, 2019
Professor Lazarova and her Astronomy 100 students hosted close to one hundred 4th graders from Scott Elementary school for an exciting day of astronomy-related hands-on activities. Participants had a chance to (safely) explore the surface of the Sun, discover how light interacts with matter, visualize our expanding universe, witness how Einstein described gravity, learn how craters form, and much more!
September 28, 2019
UNC Physics major Jace Bobo poses with a proud mom and dad and an excited Prof. Chaloupka after a stunning Bears Football win. Jace stopped a fourth quarter Idaho drive with a play-of-the-game interception, setting up the Bears for the game-winning field goal. Go UNC Physics and Go Bears!!
August 2, 2019
Prof. Kuehn and collaborators recently published an article in the journal Acta Astronomica on Variable Stars in M13. III. The Cepheid Variables and their Relation to Evolutionary Changes in Metal-poor BL Her Stars.
June 24, 2019
Profs. Charles Kuehn and Dick Dietz attended the Muscular Dystrophy summer camp at Rocky Mountain Village in Empire, CO. They helped campers look at some binary stars, a globular star cluster, and Jupiter through telescopes, and attendees even got to hold one of the department meteorites.
May 4, 2019
Congratulations Physics & Astronomy graduates!
(left-right): Sergio Chacon, Jordan French, Robert Ensley, Tyler DeVerse, Rydell Stottlemyer,
Juan Marcos Avina, Natthakan Koetchaeng, Alec Bennington, (not pictured): Daniel Herrera,
Joseph Maletta, Tyler Onufrak, Clayton Orback, Andrew Roth, Quinton Snouffer
May 3, 2019
Dr. Charles Kuehn, Dr. Mariana Lazarova, and student Alec Bennington visited S. Christa McAuliffe STEM Academy in Greeley as part of their annual Star Wars Day (May the Fourth) festivities. Over 550 students learned about how we see far, far away galaxies as they were a long time ago, how black holes work, and the differences between asteroids, comets, meteors, and meteorites; students even got to hold a real meteorite.
April 28, 2019
Graduating physics major Clayton Orback, who has successfully completed the upper-division honors program, was awarded the Becky R. Edgerton Memorial Honors Scholarship Award for outstanding honors thesis! Congratulations Clayton, this prestigious university-wide award is the result of your hard work, creativity, and commitment to your research project.
April 20, 2019
Five students from UNC’s Department of Physics and Astronomy presented their research at the 2019 Colorado Undergraduate Space Research Symposium held at the University of Colorado at Boulder. Their work was sponsored by the Colorado Space Grant Consortium. The COSGC is funded by NASA and is a state-wide organization involving 21 colleges, universities and institutions around Colorado. UNC students Rydell Stottlemyer, Brian Smith, Robert Ensley, Quinton Snouffer, and Juan Marcos Avina met with members of the aerospace community from Colorado and beyond as they discussed their projects. Avina earned a prize for best poster in his category of research.
April 13, 2019
UNC Physics & Astronomy was well represented at the American Physical Society April Meeting held in Denver April 13-16, with three poster presentations and an oral presentation. Pictured here, Juan Marcos Avina, Clayton Orback, and Noah Blair discuss their research with interested meeting participants.
April 13, 2019
Dr. Courtney Willis, Dr. Charles Kuehn, and UNC Physics students Quinton Snouffer and Sergio Chacon astounded a packed house with several entertaining "magical" demonstrations. The event took place on Saturday, April 13th at 2:00pm at Loveland Aleworks. Also, check out the article on a previous Physics & Foam event in the UNC Mirror.
April 13, 2019
Undergraduate students from UNC’s Department of Physics and Astronomy designed, constructed, and tested an experiment that was part of a balloon payload launched from Eaton Middle School in Eaton, CO on April 6th. Their work is a part of the DemoSat Program conducted by the Colorado Space Grant Consortium. UNC is one of twenty-one higher-learning institutions in the consortium. Rydell Stottlemyer and Brian Smith designed a container that minimizes the pressure changes experienced during high-altitude flight. Many balloon experiments require that the pressure remain relatively constant and close to one atmosphere. Their container will serve as the template for future payloads. The flight went smoothly as the balloon reached a maximum altitude of approximately 14 miles. With their payload recovered, Rydell and Brian are currently analyzing the data collected by several sensors which were programmed to function autonomously during the balloon’s journey.
March 3, 2019
Congratulations to the 2019 UNC Physics & Astronomy Academic Scholar Award winners! Awardees were honored at the NHS ceremony on Sunday, March 3. Pictured left to right: Juan Marcos Avina, Natthakan Koetchaeng, Alec Bennington, Noah Blair, Quinton Snouffer, and Sergio Chacon.
January 20, 2019
A total lunar eclipse was visible across the United States on Sunday, January 20th. This was the last total lunar eclipse anywhere in the world until 2021 and the last one visible in Colorado until September, 2025. Members of the University of Northern Colorado Physics and Astronomy department held a special eclipse viewing session at the UNC Astronomy Lab.
January 4, 2019
Prof. Semak presented a poster at the Dynamics Days conference held at Northwestern University January 4-6 2019 on Examining Human Unipedal Quiet Stance: Smoothness.
November 29, 2018
Prof. Mariana Lazarova and her intrepid Astronomy 100 students held a massively successful outreach event for 100 local 4th grade students at the University Center. Students took part in fifteen activities on topics ranging from the sun, the moon, and the galaxy, to filtered light, rockets, dark matter, and climate change.
October 12, 2018
UNC Physics students Sergio Chacon, Maya Davidson, and Tyler Onufrak recently attended the APS Four Corners Section Meeting in Salt Lake City, Utah. Maya served on the organizing committee, and Tyler presented his work on Imaging and Mapping of Quantum-Like Behavior in a Hydrodynamic System.
October 12, 2018
Profs. Mariana Lazarova and Charles Kuehn talked about Astronomy and Light at the Fort Collins Museum of Discovery Astronomy Day.
August 24, 2018
Physics major Jacob Fry received funding from the UNC Office of Undergraduate Research for his summer research with Prof. Sung. Jacob has been looking at a variety of shark tooth samples to differentiate imaging capabilities and limitations between AFM (Atomic Force Microscopy) and SEM (Scanning Electron Microscopy), as well as developing a new pedagogical approach of introducing nanoscience research into undergraduate curriculum.
March 25, 2018
Congratulations to the 2018 Physics & Astronomy Academic Scholar Award winners: (top L-R) Joshua Fender, John Ringler, (bottom L-R) Clayton Orback, Andrew Roth, (not pictured: Rydell Stottlemeyer, Caleb Dahlke).
February 1, 2018
Congratulations to Dr. Semak! He was awarded the Undergraduate Research Mentor of the Year Award at the NHS Excellence Awards Ceremony.
October 21, 2017
UNC Physics presented three talks and four posters at the APS Four Corners Section Annual Meeting held at CSU:
Doing Research with Undergraduates in a Bachelor's-only Physics and Astronomy Department: Challenges and Successes (Dr. Semak), Ionization Dynamics in Intense Bicircular Laser Fields (Dr. Chaloupka), Thermodynamic Studies of Phase Transitions in Inflationary Cosmology (Dr. Mallory), Measuring Atmospheric Muon Flux during the 2017 Solar Eclipse (Fender, Ringler, Morse), Electroencephalography and the Mechanical Operation of an Exoskeletal Arm (Helms, Zadina), Postural Control: A Sample Entropy Approach to One-Legged Stance (McMillan), Biomimicry: Designing and Building a Multilegged Robot (Sweitzer).
August 2, 2017
Prof. Chaloupka teamed up with CU-Boulder, publishing their recent work on Observation of Ionization Enhancement in Two-Color Circularly Polarized Laser Fields in Physical Review A.
March 26, 2017
Congratulations to the Physics & Astronomy Academic Scholar Award winners, seen here with Professor Matt Semak at the NHS College event. (top, L-R): Semak, William Mendoza, Ryan Fabian, Arick Sweitzer, (bottom, L-R): Alexandra Briggs, Kourteney Zadina, and Zachary Rossiter.
April 29, 2017
UNC Physics was well represented at the Colorado-Wyoming Section Meeting of the AAPT, where students presented FIVE posters:
Biomimicry: Design and Construction of a Mulitlegged Robot (Sweitzer), Investigating the Impact of a Solar Eclipse on Atmospheric Radiation (Fender, Ringler, Morse, Angstead), Postural Control: A Sample Entropy Approach to One-Legged Stance (McMillan, Semak, Heise), Electroencephalograpy and the Mechanical Operation of an Exoskeletal Arm (Helms, Zadina), Psychoacoustics: Understanding Sonic Intelligibility (Briggs)
April 15, 2017
UNC Physics & Astronomy students Ryan Angstead, Cody Helms, Arick Sweitzer, and Brandon Williams participated in the 2017 COSGC Robotics Challenge at the Great Sand Dunes National Park on April 15. Check out the video for footage of Arick's award winning multi-legged robot!
April 6, 2017
UNC Physics & Astronomy presented five posters at UNC Research Day, on topics of processing power in robotic rovers, control of exoskeletal arms, biomimicry in robotics, solar eclipse research, and entropy analysis of postural control.
February 17, 2017
Congratulations to Zach Armstrong (UNC Physics Alumn and Greeley West high school science teacher) for being named one of nine nationwide PhysTEC teachers of the year!
January 6, 2017
Prof. Semak presented work on Postural Control: A Study of One-Legged Stance at the Dynamics Days 2017 conference held in Silver Spring, MD.
December 10, 2016
Congrats to our Fall 2016 UNC Physics grads (L-R): Derek Bernard, Veronica Buchanan, Shelby Burns, Carolyn Shaw (Math), Stefan Lamb.
October 21, 2016
Prof. Chaloupka presented work on Ionization dynamics in intense two-color circularly polarized laser fields and Surface profilometry using vortex beams at the OSA Frontiers in Optics conference in Rochester, NY.
September 20, 2016
Prof. Chaloupka teamed up with CU-Boulder, publishing their recent work on Controlling Nonsequential Double Ionization in Two-Color Circularly Polarized Femtosecond Laser Fields in Physical Review Letters.
August 22, 2016
UNC Physics welcomes new faculty member Ansel Foxley!
July 25, 2016
Profs. Semak, Galovich, and Dietz presented their work on Can a Nonverbal Intelligence Test Predict FCI Performance at the AAPT Summer Meeting in Sacramento, CA.
July 13, 2016
Prof. Kuehn presented work on RR Lyrae Stars in M4 at the Kepler Asteroseismic Science Consortium Conference held in the Azores.
May 7, 2016
Congratulations to our UNC Physics & Astronomy Grads! Among those at the May 7 commencement ceremony: Chad Garcia, Grant Harris, Lauren Hoots, Casey Montoya, Patrick Morales-Mendoza, JJ Peek, and Matt Svetic!
May 4, 2016
UNC Physics and Philosophy double major Alex Lidiak profiled on UNC website.
April 17, 2016
Congratulations to the 2016 Physics & Astronomy Academic Scholar Award winners: Derek Bernard, Brad Holmes, Phakawat Manusnon (top, L-R) and Veronica Buchanan, Margaret Hodge, Lauren Hoots (bottom, L-R).
April 9, 2016
UNC Physics participated in a successful DemoSat balloon launch. Members of the team include Ryan Angstead, JJ Peek, Mike Nuzum, Alexandra Briggs, Arick Sweitzer, and Taylor McMillan (L-R).
April 7, 2016
Prof. Chaloupka published work on the Dynamics of Strong-Field Double Ionization in Two-Color Counterrotating Fields in Physical Review Letters.
December 16, 2015
Prof. Adams, Zach Armstrong, and Prof. Galovich publish work on Can students learn from PhET Sims at home, alone? in the 2015 PERC (Physics Education Research Conference) Proceedings.
November 1, 2015
Profs. Adams and Willis publish article Sparking Curiosity: How Do You Know What Your Students Are Thinking? in The Physics Teacher.
May 9, 2015
Two of our happy graduates at commencement: Donovan Anderson (L) and Amber Bekkali (and proud dad!) (R). Also present: Lee Ismay, Kyle Nachbar, Casey Rogers, Anthony Saccomanno, Graham Stringert, Derek Weigle, and John Wood.
April 18, 2015
UNC Physics students presented their research at the Colorado Space Grant Symposium held in Boulder, CO. Clockwise from upper left: JJ Peek & Graham Stringert, Lee Ismay, Jeremiah Schwartz, Lee explaining his work.
April 12, 2015
Congratulations to the 2015 Academic Scholar Award winners: Alex Lidiak, Amber Bekkali, Patrick Morales-Mendoza (L-R top), Taylor Plantt, Steven Rutherford (L-R bottom), and Anthony Saccomanno (not pictured).
April 11, 2015
UNC Physics students Donovan Anderson, Amber Bekkali, and Ryan Fabian participated in a successful DemoSat balloon launch.
April 11, 2015
Prof. Chaloupka presented work on Supercontinuum Optical Vortices at the Colorado Ultrafast Photonics Initiative (CUPhI) workshop held in Granby, CO.
April 4, 2015
UNC Physics students JJ Peek, Anthony Saccomanno, and Graham Stringert participated in the NASA Colorado Space Grant Consortium Robotics Challenge at the Great Sand Dunes National Park.
January 18, 2015
Maggie Hodge (L) and Amber Bekkali (R) attended the 2015 APS Conference for Undergraduate Women in Physics at UT-Brownsville.
October 22, 2014
Prof. Chaloupka presented work on Color Schlieren Imaging with Monochromatic Sources at the 2014 OSA Frontiers in Optics conference in Tucson, AZ.
October 9, 2014
UNC Physics major Zach Hafen presented his work on modeling balance with stochastic processes at the Colorado Space Grant Symposium at CU-Boulder.
July 26, 2014
May 10, 2014
Congratulations to the 2014 UNC Physics graduates: Ben Carlson, Steve Champion, Zach Daubert, David Garrett, Eric Gregg, Zach Hafen, Marius Herlea Jr, Sean Higgins, Tim O'Neill, Michael Schmidtbauer, Jeremiah Schwartz, Danny Thistle, and Josh Wadle.
April 7, 2014
UNC Physics was well represented at the Colorado Space Grant Consortium Robotics Challenge held April 5 at the Great Sand Dunes. Graham Stringert, David Garrett, JJ Peek and Anthony Saccomanno piloted their rover across challenging terrain.
March 30, 2014
Congratulations to the 2014 Physics Academic Scholar Award winners: Danny Thistle, Zach Hafen, Lee Ismay (top, L-R), Marius Herlea Jr, Casey Rogers (bottom, L-R).
March 28, 2014
UNC Physics published their work on Color schlieren imaging with a two-path, double knife edge system in the journal Optics Express. The work was carried out by Dr. Chaloupka and Maurice Woods and Danny Thistle (UNC Physics undergrads) and Jacob Aas and Jessamyn Hutchins (FSI high school students).
January 17, 2014
UNC Physics major Amber Bekkali attended the American Physical Society 2014 Rocky Mountain Conference for Undergraduate Women in Physics at the University of Utah in Salt Lake City.
January 4, 2014
UNC Physics (Semak, Dietz, Adams, Jordan) presented Clarifying the Force Concept Inventory via Think-Aloud Interviews at the AAPT Winter Meeting.
October 7, 2013
The UNC Physics (Chaloupka) - San Diego State University collaboration presented their work on Vortex Interference Effects from a Segmented Spatial Light Modulator and a Supercontinuum Source at the OSA Frontier in Optics Meeting in Orlando, FL. In the image above, brilliant full-color images of vortex interference are demonstrated by theory (L) and experiment (R).
May 10, 2013
Congratulations to the 2013 UNC Physics Grads (L-R): Herve Tonye Tonye, Joe Gasteiger, Audrey Wall, Isaac Lorentz, Travis Day, Albert Einstein (not a UNC grad), Carlos Gallegos, Bronson Pausa, Michael Clay, Richard Pacheco.
March 10, 2013
Congratulations to the 2013 UNC Physics Academic Scholars: Michael Clay & Travis Day (L-R, top) and Karin Ficek & David Garrett (L-R, bottom).
July 16, 2012
An image of a supercontinuum optical vortex diffracted through a triangular aperture from the recent JOSA B article on Measuring the topological charge of ultrabroadband, optical-vortex beams with a triangular aperture. Since the extreme spatial chirp is compensated for in the experiment, the topological charge can be determined by counting the spots along each side of the triangle. UNC Physics (Chaloupka), SDSU, and Universidade Estadual de Campinas in Brazil teamed up for this work.
June 14, 2012
Images of the devil's vortex pattern from the recent article in Applied Optics on the Experimental realization of the devil’s vortex Fresnel lens with a programmable spatial light modulator. Experiment (top row) and theory (bottom row) show exquisite agreement. UNC Physics (Chaloupka) and SDSU teamed up for this work.
June 5, 2012
Above, images from the public viewing of the Venus Transit organized by Prof. Dietz. Below, an image contributed by V. Chaloupka of Santa Fe, NM.
May 3, 2012
Congrats to UNC Physics grads Aaron Adamson, Rob Shiely, Jordan Aken, Maurice Woods, John Arko (L-R), and Rachel Bennet (front). Below, distinguished Professor Emeritus Courtney Willis congratulates our grads at the department celebration.
April 14, 2012
UNC Physics student Jordan Aken with Dr. Matt Semak at the DemoSat balloon launch.
April 12, 2012
UNC Physics students presented their work at the UNC Research Day (top: Rachel Bennet, middle (L-R): Joe Gasteiger & Travis Day), and at the NHS Research Celebration (bottom (L-R): Jordan Aken, Maurice Woods III, Robert Shiely).
March 23, 2012
UNC Physics celebrates its 2012 Academic Scholar Award winners! Congratulations to Richard Pacheco, Audrey Wall, Jeremiah Schwartz and Zach Hafen (L-R).
September 19, 2011
Members of the Colorado Space Grant Consortium pose at the University Center at this year's annual meeting.
April 29, 2011
Dr. Semak explores the physics of his wicked split-finger fastball as he throws out the first pitch at the UNC baseball game.
April 8, 2011
Above, the UNC Robot maneuvers an alien landscape. Below, Jordan Aken, Aaron Adamson, and Diego Alcala (L-R) recreate a scene from the critically acclaimed film Capricorn One.
February 21, 2011
The distinguished RockSat Team poses for a photo outside Ross Hall.
December 13, 2010
Congratulations to our Fall 2010 UNC Physics graduates (L-R): Chris Walker, Motoaki Honda, and Jessica Gage!
