Events at Physics |
Events on Saturday, April 21st, 2018
- JIMFEST 2018
- Six Lines to Tell a Story
- Time: 9:30 am
- Place: 2241 Chamberlin Hall
- Speaker: Michael Wood, University of St. Thomas
- Abstract: In this talk, I will highlight a recently completed investigation into a challenge brought against our earlier work on vanadium. The discrepancy between six transition probabilities and its resolution touches on several aspects of transition probability research, the important contributions of our stellar collaborators, and future directions for study.
- JIMFEST 2018
- TBD
- Time: 10:00 am
- Place: 2241 Chamberlin Hall
- Speaker: Uwe Kortshagen, University of Minnesota
- JIMFEST 2018
- How I Became a Non-Chemist
- Time: 10:30 am
- Place: 2241 Chamberlin Hall
- Speaker: Ken Menningen, UW Stevens Point
- Abstract: Some scientists direct their careers with laser focus to answer a small set of questions. Others wander around like a trapped photon. I will tell the story about how a plasma physicist ended up studying combustion chemistry, and how the student he trained learned about growing diamonds, thermophoresis, synchrotrons, radiation trapping, photoelectrochemical water splitting, and anticrepuscular rays.
- JIMFEST 2018
- Studying interesting phenomena: GE and Jim Lawler
- Time: 11:30 am
- Place: 2241 Chamberlin Hall
- Speaker: Tim Sommerer, GE Global Research
- Abstract: The world is full of interesting and mysterious phenomena that can be made more understandable by applying the scientific method. This talk will focus on two examples: (i) what it means to do physics at a place like General Electric, and (ii) Jim Lawler. Observations will be reported, models will be proposed, and conclusions will be drawn.
- JIMFEST 2018
- Gas Discharge Lamps – A Requiem
- Time: 12:00 pm
- Place: 2241 Chamberlin Hall
- Speaker: Graeme Lister, Lighting Consultant
- Abstract: Almost a century has passed since the introduction into the market of gas discharge lamps for general lighting in the form of fluorescent lamps, made possible by the discovery of phosphors able to convert ultra-violet (UV) light to visible light in 1924. The journey from the first fluorescent lamps to, efficient lamps producing high quality light was an exciting one for researchers, and much of the basic theory of gas discharge physics was developed by scientists during the early stages of gas discharge development. The trend for steady improvement continued through the end of last century, but the discovery of efficient blue light emitting Light Emitting Diodes (LEDs) in the 1990s provided a path for lamp efficacies undreamed of and unattainable by gas discharge sources. These “legacy” lamps will remain with us for many years, perhaps decades to come, but the overriding trend in the market is towards introduction of LEDs for most general lighting applications, due to the huge energy savings that will accompany them. There are certainly niche markets where LEDs have difficulty competing, but the general trend appears irreversible.
This talk will take an affectionate and nostalgic backward look at the gas discharge research for lighting to which I have devoted much of my career. Most of the successes I have had would not have been possible without the inspiration, insight and friendship of Jim Lawler. The number of papers we have published together bears testimony to this. The talk will describe a journey along the paths we trod to understand how gases produce light, the fundamental principles involved, the experiment performed and the means of interpreting the results. Topics include studies of the negative glow, the positive column, and an extended look at “electrodeless“ fluorescent lamps and the efforts made to understand their performance. More recent efforts to produce electrodeless metal halides will be discussed, and finally a view on applications of discharge lamps in the expanding market of lighting for plant growth.