LASER: Materials Science podcast

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Hark | 8 | The Queen's English 29:53

11 hari yang lalu29:53

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Living together in a group is a strategy many animals use to survive and thrive. And a big part of what makes that living situation successful is listening. In this episode, we explore the collaborative world of the naked mole-rat. Threshold is nonprofit, listener-supported, and independently produced. You can support Threshold by donating today . To stay connected, sign up for our newsletter . Operation frog sound! Send us your frog sounds for an upcoming episode. We want you to go out, listen for frogs and toads, and record them. Just find someone croaking, and hit record on your phone. It doesn’t matter if there’s background noise. It doesn’t even matter if you’re not sure whether or not you’re hearing an amphibian—if you think you are, we would love to get a recording from you. Please also say your name and where you are in the world, and then email the recording to us at outreach@thresholdpodcast.org…

LASER: Materials Science Podcast

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Discussing recent publications and news in materials science, physics, and engineering fields.

26 episode

#Engineering #Business #Science #Tech #Industries #Natural Sciences #Podcasting Education #LASER Materials Science

LASER: Materials Science Podcast

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updated 5 tahun yang lalu

Beranda serial•Feed

Discussing recent publications and news in materials science, physics, and engineering fields.

26 episode

#Engineering #Business #Science #Tech #Industries #Natural Sciences #Podcasting Education #LASER Materials Science

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LASER: Materials Science Podcast

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Episode 21 – Underground with Dr. Sarah Truebe 51:59

5 years yang lalu51:59

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Graffiti removal during the Peppersauce cave cleanup project In this episode Cameron interviews Dr. Sarah Truebe, the cave resource manager at Kartchner Caverns State Park in Arizona. This episode was recorded underground at the end of a day we spent cleaning graffiti out of this popular wild cave. We discuss how Dr. Truebe got started caving, how some cave research is performed, and some ethics of destructive testing methods in sensitive cave environments. Show Notes: 3:00 Sarah talks about her experience on her first caving trip (right in the cave where we were sitting!) and a bit about cave safety 5:00 White nose syndrome is discussed, a fungal disease killing bats across North America. 10:20 How Sarah got interested studying the monsoon at a young age, and how that turned into studying paleo climate in grad school. 20:20 What are the ethics of paleo climate studies in caves? How can we study delicate and irreplaceable features? 35:50 After a cave (like Kartchner) been studied for 50 years, what is left to do and monitor long-term? 40:00 CO2 variations in caves 45:20 How people can submit a proposal for a cave study that could potentially be approved in a cave like Kartchner. Links: To learn more about or visit Kartchner Caverns, visit https://azstateparks.com/kartchner and follow them on Facebook To find a local caving club (grotto) or learn about the National Speleological Society, visit https://caves.org/ If you are totally new, maybe start with the “Guide to Responsible Caving” brochure As always, if you are doing interesting research you want to talk about, or have any interesting topic ideas, please get in touch and we may be able to do a show about it. Thanks to Ray Keeler for organizing the Peppersauce Cave Cleanup Project event that this interview was recorded during.…

LASER: Materials Science Podcast

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Episode 20 – Room Temperature Superconductivity Controversy 36:37

7 years yang lalu36:37

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questionable data in χ, pointed out by Brian Skinner [arXiv:1808.02929] We’re back! You may have heard about some controversy surrounding a recent pre-print published on the arxiv about room temperature superconductivity. This would be an extremely exciting result if it weren’t for some issues. The authors won’t share their samples and have not yet fully described how to make it–they say that will come in a future publication, and there is some question about the veracity of two plots in one of their very important figures. The pre-print publication is available to read free here: https://arxiv.org/abs/1807.08572 The arxiv comment submitted questioning the data is here: https://arxiv.org/abs/1808.02929 And the twitter thread from the researcher who noticed the questionable data (@gravity_levity on twitter) is here: https://twitter.com/gravity_levity/status/1027717419400392705?s=19 Ars technica recently published an article about this controversy: https://arstechnica.com/science/2018/08/room-temperature-superconductivity-claim-has-side-dish-of-dodgy-data/ for some background information and citations for things I talked about: Here is a list of Tc and Hc2 for metallic superconductors: http://hyperphysics.phy-astr.gsu.edu/hbase/Tables/supcon.html#c some commercial applications of superconductors (not completely up to date): http://www.ccas-web.org/superconductivity/wireless/ an in-depth article from a tech website: https://thewire.in/the-sciences/did-iisc-team-find-a-room-temperature-superconductor-the-devils-in-the-details While I was taking notes, I ended up writing them like a blog post instead of just my normal index card podcast notes, so here is an approximate transcript of the entire episode: I wanted to share a recent paper that has been making some waves among the scientific community and on twitter about a claim of room temperature superconductivity. I’ll probably regret speaking out about this so early, so I’ll maybe treat this like a paper review and we’ll see how the data work out with peer review and reproducibility. A group from the respectable Indian Institute of Science, graduate student Dev Kumar Thapa and associate professor Anshu Pandey, have posted a pre-print paper on the arxiv called Evidence for Superconductivity at Ambient Temperature and Pressure in Nanostructures. Since this is the arxiv, this is an unfinished pre-print of a paper, not a peer-reviewed manuscript in final form, but it is a fast way to get it out and free to read. There will of course be links in the show notes. The most important part is they claim to have measured superconductivity at 236 K in silver nanoparticles embedded in a gold matrix. This claim is really remarkable when you look at other superconductors. A regular metal superconductor has a Tc less than 9.2 K, which is the highest Tc metal, Niobium. After this, the high temperature binary alloys go up a little bit toward 30 K, and the high temperature cuprates are all very complex structures like YBCO, BSSCO, and HBCCO are 92, 110, and 133 K respectively. Im going to start off ignoring the current controversy and saying that overall this paper is not bad, the claim is extraordinary but they characterized their material extensively, and documented all the things that I would have asked for. Assuming the data are correct and independently reproducible, this could be a very serious discovery. So before I get too deep into the paper here’s a really quick summary of superconductors for anyone who might not know what they are. A superconductor is a material that conducts electrons with no resistance, they are important for high tech devices and scientific research, and especially in wireless communications and extremely sensitive sensor applications. The primary goal here is to build these high tech devices that require the unique properties of superconductors, not to get zero-loss power lines (although there is a group trying that). The two types of superconductor are those that screen or block magnetic fields completely (these are Type I superconductors) and those that allow magnetic fields to pass through tiny pinholes of normal material called fluxons or flux vorticies (these are Type II). The easy way to guess which type a superconductor is is just to remember that for the most part, pure metal superconductors are all type I (as in they exclude magnetic fields completely until the field gets so strung it shuts off the superconductivity completely, this is called the Meisner effect), while compounds are mostly type II (as in they allow magnetic fields through little flux vorticies up to a point where the field destroys superconductivity completely). These magnetic fields are referred to as Hc1 and Hc2 (as in H, the magnetic field, c for critical, 1 where flux vorticies are formed and 2 for where superconductivity is destroyed completely). Okay, that should be enough background for what I’m going to say, so on to the publication. Like I said earlier, their remarkable claim is to have measured superconductivity at 236 K in nanostructures of silver nanoparticles (about 10 nm) embedded in a gold matrix. An easy thing to point out is that neither gold nor silver are superconducting on their own, and based on their chemical and structural analysis this is not an alloy, so these support the authors’ claim that the property has something to do with the nano structure. • Their structures at large (micron) scale don’t have good uniformity, but this is pretty typical for this type of work, and the actual nano particles have good uniform size distribution and shape (this of course coming from someone who doesn’t ever work with nanoparticles). After that is the part where I start having little issues with things. Now, a little context I spent over a year working with unvalidated claims of room temperature superconductivity in the past, and I’m also currently writing my dissertation, so I am in the mindset to look critically at everything as “this could be better if.” I’m saying this because want to point out that this part of the discussion isn’t ripping the authors work apart, just offering criticisims on a paper that isn’t peer reviewed or published yet. These are the same things the reviewers and editors will also pick up and fix before final publication. The 2nd figure shows the resistance vs temperature transition • R-T drop is good, clear and obvious resistance drop indicative of superconductivity, and this is the normal way you would check for it. The weird thing about this figure 2-a where they show the resistance vs temperature is that they are reporting the data in resistance instead of resistivity. Resistance is kind of a rough measurement because its so dependent on measurement geometry and sample size and thickness. This kind of result should be in resistivity so that it is universal. • From a quick calculation of resistivity, even at “normal” temperatures this gold is very conductive for such a thin film, especially one that is nanostructured. The normal resistivity is comparable to that of pure gold, and while its hard to increase the resistivity of gold by adding contaminants, these nanostructures don’t look like they are continuous and probably shouldn’t be so conductive. • Figure 2-B is fine data, but axes backwards hard to read (magnet field is independent variable should be on x) • Figure 3: other way to detect superconductivity is magnetic susceptibility o A few weird units in the paragraph, g/cc and “(si units)” for susceptibility is switching from CGS to SI, and also weird medical. o Susceptibility goes to -0.06, should be -1 for perfect diamagnet (superconductor) suggests only 6% of material is superconducting (they blame on imperfect sintering- could be, wouldn’t detract from discovery) o Same issue with independent variable on y-axis o Brian skinner post-doc @ MIT pointed out on twitter and published in arxiv o Unlikely to be a repeatable noise because its not the same in all the runs o The data changes halfway up so that the transitions are different o Looks like one or two of these curves could be faked or manipulated. • Figure 4: a is interesting, shows decreasing gold fraction increases Tc (why did they pick a the 236 K sample to focus their paper on) o Doesn’t include their highest temperature specimen, even an arrow or blank space. o Figures b and c are pretty useless, and not sure what they are showing or why. Even after reading, these seem unnecessary and not helpful. B is just noise but not labeled in the figure or anything and C is not noise even though it should be. • In the supplemental, my first issue is with S3, this is a blurry screenshot of a EDS spectra form an analysis software, not an publication quality original graphic with most of the peaks labeled but not all of them. It would have been wise to label the giant copper peak from the grid so that people who see it and don’t recognize it immediately know what that element is. • Then figure S8 is just “transitions in resistivity as observed in three different NS samples” no descriptions or indication why we want to see three random samples after already seeing a bunch of this measurement. Also the resistance and pattern is significantly different than the figure directly above it, S7. Just looks sketchy.…

LASER: Materials Science Podcast

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Episode 19 – 2015 Perihelion Edition 57:35

10 years yang lalu57:35

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1) aphelion 2) perihelion 3) sun (Not to scale) source: WIkipedia on Apsis Welcome to 2015! This year’s perihelion edition was recorded on the day which the earth is closest to the sun. We cover a diverse list of important scientific and engineering happenings from 2014, and even talk about a little biology and genomics research! (but don’t worry, its mostly cool physics, space, and engineering stuff.) 4:00 Many of these stories came from this big summary graphic that was posted on /r/futurology. Don’t worry, we looked up real sources for everything! 7:30 the big bang BICEP 2 discovery ( and controversy and final dismissal ) 11:09 There was also controversy with a fraudulent report of a way to make induced pluripotent stem cells (IPC) by dipping them in a light acid. 14:08 artificial white blood cells (used as an injectable “cancer vaccine” ) 15:00 Gene therapy used in eyes to help treat macular degeneration 18:00 There were a pair of genetically engineered monkeys born this year! and we have a bunch of discussion about ethics 25:30 we finally move on from Biology back to physics! 26:40 removing hydrocarbons from seawater. (like we talked about in Episode 16 ) 29:00 “Visual microphone” reconstructing audio from tiny vibrations in videos. Great for spys and burn notice! 33:50 space and disasters ( Virgin Galactic’s SpaceShipTwo & Orbital Sciences Antares Rocket ) 36:00 space is hard. but really important for the future of humanity and science! 41:00 The Curiosity rover might have detected methane on Mars ! 44:00 computers and data security were kind of bad this year. We discussed this in detail on our Heartbleed show (our most popular episode ever!) but things have continued and are very bad both in terms of security, and internet freedom. 47:30 Cosmos was pretty cool, except chase doesn’t like NGT because chase hates everything other people love.…

LASER: Materials Science Podcast

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Episode 18 – Space Space Space 55:44

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Can’t really tell which is the 3-d printer and which is the espresso machine… Images from Lavazza and Made In Space We’re finally back from our long hiatus! Sorry about the wait, both Cameron and Emily were busy getting their masters degrees, and right after he submitted his thesis, Cameron’s laptop got fried! This week we discuss Space X and Boeing contracts to transport NASA astronauts to the International Space Station by 2018, and some new luxuries that will soon be available on the ISS; a 3-D printer, and an espresso machine! 2:00 First story today is about the recent announcement that NASA will have contracts with SpaceX and Boeing to deliver astronauts to the international space station by 2018! http://www.space.com/27169-nasa-picks-spacex-boeing-spaceships.html 15:00 we wonder about the nomenclature for spaceships/vehicles/shuttles/capsules 24:00 we start our discussion on coffee with a unrelated mention that Starbucks is working on a coffee drink that is supposed to taste like beer ? 26:00 the ISS-Presso is an espresso machine planned to go to the space station at the end of 2014. https://twitter.com/AstroSamantha/status/478219649721839616/photo/1 http://www.wired.co.uk/news/archive/2014-06/14/isspresso 40:00 on to 3-D printing in space!!! The company “Made In Space” is working with NASA to send one of their fillament-extrusion 3-D printers onto the ISS for an experiment to show that the additive manufacturing technique works in space without modification. http://www.madeinspace.us/ http://www.nasa.gov/mission_pages/station/research/experiments/1115.html 44:00 technology readiness levels, whatever those are. Links to the music used in this week’s episode: Intro: Intro – Crying ( Return to Olde World ) Outro: Dreams are Maps – The Wild ( Dreams are Maps )…

LASER: Materials Science Podcast

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PULSE! #4 – Better Coffee Through Chemistry 23:05

11 years yang lalu23:05

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Image from Wikipedia with slight modifications Most coffee-particular people already know that the quality of the water you use is important for good coffee, but a recent paper describes how affecting the specific hard mineral content can have important changes in the relative extraction of specific flavor and strength affecting chemicals in your brew. We discuss the basics of coffee preparation, and the conclusions of the paper. 1:15 Greg throws out a Leeroy Jenkins reference right off the bat. (I guess wait for episode 32.33?) 2:00 the article that prompted this show was “ A Chemist Has Uncovered A Secret To Brewing Delicious Coffee At Home ” published in Business Insider on Jun 5th, 2014. 2:45 The paper is called “The Role of Dissolved Cations in Coffee Extraction” , by Christopher H. Hendon, Lesley Colonna-Dashwood, and Maxwell Colonna-Dashwood, published in the Journal of Agricultural and Food Chemistry. 3:50 The researcher identified seven chemicals important to the flavor and strength of coffee, and used density functional theory to calculate the bonding energy between these chemicals and common ions in water that contribute to water hardness. 6:45 one of the chemicals present in Coffee, eugenol , is also present in whisky and other barrel-aged liquors. 16:00 It might be useful to suggest to coffee brewers to use distilled or reverse osmosis water and then add something similar to these brewing salts to the water to facilitate extraction! 18:10 The paper only talks about water with Total Dissolved Solids (TDS) of <300 ppm, which is standard for municipal water supplies, but well or ground water in areas (like our own Phoenix area) can have much more calcium hardness than that. Links to the music used in this week’s episode: Intro: Intro – Crying ( Return to Olde World ) Outro: Dreams are Maps – The Wild ( Dreams are Maps )…

LASER: Materials Science Podcast

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Episode 17 – Life, The Universe, and Frogs 1:11:25

11 years yang lalu1:11:25

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This week on LASER we discuss a realistic computer simulation of a universe, a proposed mechanism for why tin whiskers are destroying our most sensitive computers, and GaInSn liquid metal used to reconnect severed nerves in frogs. 5:00 Our first story is about the story “Astronomers create first realistic virtual universe” from the Illustris Project . 15:40 By “first realistic simulation” they probably mean that this is the first simulation that results in a realistic distribution of galaxy types. 16:40 One of the most important thing about this simulation is being able to “see” how galaxies evolve and form and interact with each other, and since it is a computer simulation we are able to look into the past and future. 22:05 maybe eventually we’ll be able to look for distribution of M-class planets. 25:00 after talking about videogames, reddit, minority report, and cutting a five minute discussion on the history of neckbeards (https://en.wikipedia.org/wiki/Neckbeard#Neckbeard) we finally move onto the second topic… 25:30 Whiskers!!! ( http://news.sciencemag.org/physics/2014/05/scienceshot-how-shave-metal-whiskers ) 26:45 Whiskers are when a thin single-crystal piece of metal grows (very quickly) out of a metal (most often something used in solder or semiconductor packaging). This causes problems for electronic devices, where it can short out devices, and has been attributed to taking offline three satellites and one nuclear power plant (specifically places where you can’t go in and fix a part. This also has taken out many computers that just stopped working for seemingly no reason). 28:15 Lead-free solders are especially prone to this problem, because they often contain Tin. We would prefer to use lead-free because of the environmental and health effects, but it is–so far–the most reliable available solder, based on whiskers and microcracking. 34:50 The paper is V. G. Karpov, “Electrostatic Theory of Metal Whiskers” Phys. Rev. Applied 1, 044001 – Published 15 May 2014. doi:10.1103/PhysRevApplied.1.044001 37:00 the proposed mechanism for whisker buildup is charge differences on the surface, that are centered around defects. This extra energy might give the metal the energy it needs to grow directly out. 44:40 Now we’re talking about Liquid Metal nerve grafts in frogs! http://www.newscientist.com/article/dn25510-terminatorstyle-liquid-metal-connects-severed-nerves.html#.U5DWzzk2pHT and the paper freely available on the arXiv: http://arxiv.org/abs/1404.5931 The researchers have used a GaInSn liquid metal to connect severed nerves in frogs, and it resulted in connectivity similar to a healthy nerve, allows for the nerves to grow back, and is easily removed once it is no longer necessary. 55:00 fun prank for dinner parties: cast spoons out of low-temperature melting metals, and give them to your friends to stir their coffee. The spoon will melt in their drink, likely poisoning them! (not a fun prank.) Links to the music used in this week’s episode: Intro: Luv Rulez (Original version of ES) – Crying ( Return to Olde World ) bumper music: Vacation – Crying Outro: Dreams are Maps – The Wild ( Dreams are Maps )…

LASER: Materials Science Podcast

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Episode 16 – Sun & Surf 1:00:41

11 years yang lalu1:00:41

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Source: The Wikipedia For our first episode of the summer on LASER: Let’s Agree Science & Engineering are Rad, we discuss our own Chris’ recently-accepted paper about inorganic ZnS window layers on organic solar cells. These increase the efficiency, and help protect the cell from environmental damage. We then talk about the NRL Press release describing long-chain hydrocarbon fuel (jet fuel) they have made by extracting CO2 and Hydrogen from seawater! 4:00 We’re all back from traveling for work and conferences, finals are done, and Chris just finished his qualifying exams, so we’re back to podcasting, even if we are a little rusty. 6:00 Our first paper is somewhing Chris just got accepted into Journal of Applied Physics, and it is titled “Efficient ZnS cathode layers for orgnaic photovoltaic applications via n-type doping.” They are using an inorganic material, ZnS to replace the very sensitive organic cathode (top) layer in organic photovoltaics. Since the organic components are very sensitive to temperature and air, an inorganic cathode can protect the bottom layers. At the time we’re putting this episode out, the paper isn’t available online yet, but it will eventually be available at http://dx.doi.org/10.1063/1.4878155 32:30 We discuss the recent press release from NRL (http://www.nrl.navy.mil/media/news-releases/2014/scale-model-wwii-craft-takes-flight-with-fuel-from-the-sea-concept) describing fuel made from CO2 and Hydrogen that was extracted from seawater. There are a number of press articles about this: Discovery (http://news.discovery.com/tech/alternative-power-sources/us-navy-game-changer-seawater-turned-into-fuel-140408.htm) Business Insider (http://www.businessinsider.com/christopher-harress-us-navy-technology-to-turn-seawater-into-fuel-2014-4) and Inhabitat (http://inhabitat.com/u-s-navy-converts-seawater-into-jet-fuel-using-game-changing-technology/) are a few. 38:00 Removing Co2 from ocean water *might* have a small local effect reducing ocean acidification, but because the end result is burning a hydrocarbon fuel, it will end up just going back into the atmosphere and back into the oceans. Links to the music used in this week’s episode: Intro: Luv Rulez (Original version of ES) – Crying ( Return to Olde World ) bumper music: Vacation – Crying Outro: Dreams are Maps – The Wild ( Dreams are Maps )…

LASER: Materials Science Podcast

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LASER Pulse! #3 – The Heartbleed 22:59

11 years yang lalu22:59

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Source This week’s LASER Pulse! is about the Heartbleed computer vulnerability. We cover the basics of the heartbleed bug, why its important, and mention that you really need to CHANGE YOUR PASSWORDS. Because this is a Pulse episode, there are little to no edits (just the intro and outro really), and the whole show is only about 20 minutes. No real show notes, just a list of a bunch of links if you want to know more. Here are links to Sam’s Blog and her Twitter . Our Guest, Samantha, wrote about “Heartbleed for people who don’t know computers good (and want to learn to do other stuff good too)” XKCD Has a great basic explanation in comic-form This Video is the most high-level description of the bug I could find. It is really neat. Here is a link to the first program that allowed millions (maybe more) of people to to gather as much secure data as possible. It probably won’t work anymore since most servers should be patched by now, but if you have your own server you can install the old version of OpenSSL to test it out. Most importantly, THIS LIST is the list of major passwords that you need to change RIGHT NOW. It doesn’t include small websites, and if you used the same password on any two sites, they are now both compromised! Don’t think hackers aren’t smart enough to write programs to try the same password, username, and email addresses on even websites that weren’t affected by this! Even if you use small variations of your password, it makes it much easier to crack if someone has part of it. Be safe online!…

LASER: Materials Science Podcast

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Episode 15 – Airships for the Future 1:24:47

11 years yang lalu1:24:47

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Image from Paper . The cast of the Technically Speaking Podcast join us to talk with about the future of super rad airships for scientific use similar to satellites! We also talk about a company planning a new method for extracting Lithium from geothermal vents, to meet the needs of the Tesla Giga-Factory. 3:00 Our guests today are Jacob and Joe from the Technically Speaking podcast ! Check out their show if you like technology, engineering, or other rad stuff. 4:15 Our first story is about AIRSHIPS! The Keck Institute for Space Studies has released a report titled “ Airships: A New Horizon for Science ” a FREE paper published on the arXiv where they explain the scientific merit of using rigid airships for scientific applications, and potentially to replace satellites. There are also articles about this on motherboard.vice and in the MIT Technology Review . 5:50 what is an airship? 8:00 The Hydrogen vs Helium debate 14:10 the ISIS project (canceled) had neat “suction cup” tethers to keep the airship down on the ground. 16:00 the scientific applications the Keck Institute found as useful were Earth sciences such as atmospheric and environmental monitoring, and for planetary/astronomical sciences a telescope could be mounted with “Hubble comparable imaging”. 21:00 Jacob brings up how well airships would work for something similar to Google’s Project Loon 24:33 CORRECTION: Scott Kelly is going to be on the ISS for a year, NOT Mark Kelly. http://www.nasa.gov/home/hqnews/2012/nov/HQ_12-406_ISS_1-Year_Crew.html 30:00 we start on the engineering problems for building airships. Including the Hydrogen vs helium debate! 32:50 Joe points out that even though hydrogen is a dangerous gas, jet fuel is pretty dangerous too! 36:50 basically everyone would love to take an airship cruise 48:15 chase leaves early to go to dinner, but Joe and Jacob aren’t scared to talk about something outside their areas of expertise! (especially if it’s related to Elon Musk haha) 50:15 We start in on a story about a company, Simbol , that is trying to produce much more Lithium for batteries , specifically to meet the needs of the planned Tesla “Giga-battery factory” 55:15 the Tesla giga-factory’s object is to combine as much manufacturing as possible under one factory, but its the opposite with a lot of political things (like defense contracting) where things are built in a ridiculous number of factories. 61:05 How we produce lithium today (harvested from brine in salt flat areas) 63:00 The earth should run entirely out of Lithium around the year 2100!!! 64:00 it is VERY important to recycle your lithium batteries, because we are very close to running out completely!!! 65:00 THIS website says that lithium is 100% recyclable, but recycling it is just not economically feasible right now. Someone should start a company storing all the lithium batteries for about 20 years until it becomes economically feasible to recycle. Then you can donate an idea fee to our podcasts!. 76:20 Thanks to our guests today! If you need another link to Jacob and Joe’s Technically Speaking podcast, its available at http://technicalyspeakingpodcast.com 79:00 You can find them on twitter at @techspeakpod We’ve changed our intro music to be something a little less obtrusive, you can buy the song or the album at the link below. Thanks to Crying for letting us use their song. Links to purchase the music used in this week’s episode: Intro: Luv Rulez (Original version of ES) – Crying ( Return to Olde World ) Goodbye Enemy Airship – Do Make Say Think Outro: Dreams are Maps – The Wild ( Dreams are Maps ) As always, the LASER Podcast is released under a Creative Commons Attribution-ShareAlike 4.0 license. The cast of the Technically Speaking Podcast…

LASER: Materials Science Podcast

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Episode 14 – Filters and Photodetectors 54:50

11 years yang lalu54:50

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Image from Paper On Episode 14 of LASER we discuss using tree branches as water filters, a new type of super-thin room temperature infrared light detector that uses graphene, and the $1 Origami Microscope. 4:05 The article in Popular Mechanics titled “A simple tree branch can become a backyard water filter” and the FREE paper in PLOS One “Water Filtration Using Plant Xylem” 5:50 The idea is to help the developing world by testing a cheap water filter that only requires a tree branch and a tube 9:00 its really great when high school students get involved with university research projects and end up publishing papers! If you’re in high school you should talk to a university professor about helping out with a research project a couple of days after class. Even if you don’t plan to study science! (why would you not plan to study science?!) 12:00 Alex joins the group for the discussion! Unfortunately he hasn’t read any of the papers… 23:15 from Motherboard.vice.com we are talking about “infrared imaging may be coming to contact lens near you” and the article “Graphene photodetectors with ultra-broadband and high responsivity at room temperature” 24:30 the article is fine, but I don’t like the headline, and I think that the author of the paper somewhat misrepresented their results to the press. 25:45 a typical infrared detector is this Superconducting Edge Detector (or Transition Edge Bolometer) https://en.wikipedia.org/wiki/Transition_edge_sensor 27:00 Alex asks a good question about the superconducting principle behind how a transition edge sensor works. 35:40 Alex thinks his eyes are bizarre 38:42 the story is found in the MIT Technology Review and is “The $1 Origami Microscope” 41:00 there was a TEDx talk about this a few years ago, when it was a $0.50 cent microscope! Since that time, it costs more because they have developed methods for brightfield and darkfield imaging, and that required a few additional parts. 45:40 We talk about roll-to-roll processing and calendaring of green ceramics. These are manufacturing techniques for many materials. 48:05 Cameron said you can’t re-crystallize Al2O3 from amorphous to crystalline forms, but that is WRONG! http://link.springer.com/article/10.1007/BF00774113 Links to purchase the music used in this week’s episode: Intro: Open – Crying ( Get Olde ) Picture of a Tree That Doesn’t Look Okay – The World Is a Beautiful Place & I am No Longer Afraid to Die Amoeba – The Adolescents Outro: Dreams are Maps – The Wild ( Dreams are Maps )…

LASER: Materials Science Podcast

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Episode 13 – Microgravity 1:04:47

11 years yang lalu1:04:47

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Logo for the ASU Dust Devils experiment This week is all about Microgravity! Chase and Cameron interview some members of the ASU Dust Devils Experiment about their plans to take dust into microgravity and learn more about how planets are formed! Then we talk about ISS experiments for fighting fires in space and on the ISS, and finally cooling atoms down to the lowest temperatures ever achieved to learn about and perform experiments for quantum mechanics. 3:40 We apologize for the low audio quality of the interview, we’ll make sure to set up more carefully next time so it doesn’t sound like everyone is talking out of a can. Hopefully you’re still able to understand and listen, because the interview is really great! 4:15 starting the interview with Jack Lightholder and Liz Dyer of the ASU Dust Devils Microgravity Experiment which will take place early next month. Its funded by NASA and the Microgravity University 5:30 They want to take multiple dust samples up into microgravity and see how these particles clump together to create a clump that might eventually form into a protoplanet or planet. 7:46 Jack explains how the plane (owned/operated by Zero-G corporation ) creates microgravity environments by flying up and then down, so its almost like skydiving inside an airplane. 8:00 used both by scientists for experiments, and photo shoots for models , tickets for these micro-gravity flights are available commercially to just about anyone who is willing to pay up. 9:30 They tried this experiment two years ago, but a bump motor caused a problem that interfered with getting any results. The problem was fixed, so everything should hopefully go smoothly this time! 10:30 they get about 40 seconds of microgravity each time, and they expect to need at least 16 seconds to get usable data. 12:00 they expect that triboelectric and static charge transfer interactions are the effects that will cause these particles to clump. 13:30 Liz talks about her research outside of this project, analyzing images of Mars’ surface and learning about dust storms. 16:55 Cameron drops his notebook on the floor and makes a lot of noise… 17:00 The real application of this information is to fill in the gaps in models of planet formation and dust interactions. 21:00 how can people get involved in this kind of cool research? One good way is to join a SEDS chapter (or ASU’s local SEDS chapter ) 22:30 an important part of this program is the community outreach component. 24:43 Check out their Indie Gogo campaign going on to help them get the last bit of travel and equipment funding. They are almost to their goal, and the campaign ends on Tuesday, March 18. You can even get one of the go-pro cameras they will use in the experiment! 28:00 We try to start off our second topic, and listen carefully to the story we introduce, because… its the wrong one! 29:05 chase realizes we’re reading the WRONG STORY! but we’ll stick with it. Here are the links to the article , and to NASA’s website about the BASS experiment . 31:30 please excuse Cameron’s bad analogy… 32:20 Fire is really dangerous on spaceships… Apollo 1 had a fire in the cockpit during a launch training before it even launched, that sadly killed all three astronauts inside. 35:41 some materials that are flame retardant on earth can actually burn faster in space because of the difference in gravity. 41:55 the NASA Cold Atom Lab (for real this time) plans to cool Rb and Na atoms down to “the coldest temperatures in the universe.” 45:45 by cooling down an atomic gas of these elements to temperatures near 1 picoKelvin, they will form a Bose-Einstein Condensate which allows us to observe quantum mechanical effects on a macroscopic scale. 47:00 The point of the experiment is to create these Bose-Einstein Condensates, and perform experiments so we can observe and learn more about quantum mechanical effects. 52:05 we finish the story and start in on an impromptu motivational speech about getting involved in science. You don’t need a degree in science or engineering, but it certainly helps. And even if you can’t devote your career to something scientific, there are lots of citizen science opportunities available. 54:00 you should check out the Sci Fund Challenge to help support scientific research in a crowd-funded format. And if you want to get involved with space, check out SEDS . 60:11 we finally sign off. Links to purchase the music used in this week’s episode: Intro: Open – Crying ( Get Olde ) Free Fallin’ – Tom Petty Hot N Cold – Katy Perry Outro: Dreams are Maps – The Wild ( Dreams are Maps ) As always, LASER Podcast is released under a Creative Commons, Attribution, Share-Alike license, so feel free to copy it, send it to people, or do whatever you like with the file, but anything you do has to link back to us and must be released under a similar license.…

LASER: Materials Science Podcast

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Episode 12 – Laserbones 55:16

11 years yang lalu55:16

55:16

On this week’s show– Laserbones–Chris and Cameron discuss laser-3-D-Printed materials based on bones (lasers & bones), the use of cremated remains for synthetic diamonds (bones), and potential space mirror technologies made out of laser-trapped polystyrene beads (lasers)! We also have our first iTunes review! Compression tests on 3-d printed micro structures ( source ) 3:23 Article from The conversation.com titled “Scientists create bone-like material that is lighter than water but as strong as steel” 3:45 The paper was published in PNAS and is titled “High strength cellular composites with 3-D microarchitecture” 9:00 the structure of these materials are 3-d laser printed plastic that is then coated with Alumina (Al2O3). 14:00 what would you do instead of building structures out of this material? Chris would build indestructible bees. 15:00 how laser-sintered 3-d printing works (this is kind of cool) 19:50 we begin on a story inspired by an NPR piece, “From Ashes To Ashes To Diamonds: A Way To Treasure The Dead” where a swiss company will take cremated remains and turn them into a diamond for you. 22:30 we talk about what dopants are used to color Al2O3 crystals like sapphire and ruby (we call the clear Al2O3 “sapphire” in the lab, but most people just know sapphire as the blue gem). 24:50 The materials science aspect of the topic, how synthetic diamonds are grown! 26:45 Oh no! we forgot to explain what a phase diagram was! check this out in the meantime https://en.wikipedia.org/wiki/Phase_diagram 28:00 for reference, the melting point of some steel is near 1500 C, which is much less than the 3000 C needed to form graphite with a direct transition (no catalyst or seed material) 29:00 just the CVD process for growing Diamond was patented by Apollo Diamond, not the CVD process in general , this is a very common technique! 32:16 newscientist.com “ Laser light makes ultra-light mirror out of tiny beads ” and the accompanying paper: “ optical mirror from laser-trapped mesoscopic particles. ” 34:09 Chris has an interesting story about mirrors used in solar cells! (you put one at the back, and it helps make solar cells collect more light and be more efficient) 36:25 back on topic! they want to use laser-trapped polystyrene beads to create mirrors that are very light and useful for space telescope. 39:30 they are slightly “cheating” by holding the beads against a glass slide, and they are holding the whole thing underwater to help with cooling the beads and to help stabilize them 47:10 our very first listener feedback segment!!! Thanks! 48:30 and our very first correction! Intro: Open – Crying ( Get Olde ) Baby Bones – Laura Stevenson and the Cans Diamond Rings – Fake Problems Black Mirror – Arcade Fire Outro: Dreams are Maps – The Wild ( Dreams are Maps )…

LASER: Materials Science Podcast

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Episode 11 – Plant Materials 1:06:06

11 years yang lalu1:06:06

1:06:06

Image of plant wires ( source ) This week on LASER we have a plant materials themed episode where we discuss cellulose nanocrystals for use in composites, using plants as wires for computing, and using green tea to synthesize gold nano-stars for cancer treatments, drug delivery, and photonics. 2:00 Introductions and Emily explains the shiny new lab she is working for! 4:30 we start in on “The Elastic Properties of nano-crystalline cellulose” calculated from first principals. ( Article and PAPER ) 6:20 the calculations from this paper come from Density Functional Theory, a complicated, but fairly accurate method of simulating material properties. 13:00 one good application for cellulose nanocrystals is in short-fiber composites. 14:00 its not exactly like glass… 19:20 Alex has never listened to an episode of the podcast. 20:20 This paper (published on the arXiv) is called “ Towards Plant Wires ” from “The Unconventional Computing Centre” of “University of the West of England” 21:20 the only electrical measurements made on plants in the past were impedance measurements on cucumbers to measure their physiological state? This seems strange, let us know if you’ve found anything else. ***We also found http://link.springer.com/article/10.1023/A:1004684310108 Measurement of the activation enthalpies of ionic conduction in apples” *** 22:20 they measured the electrical properties of 3-4 day old lettuce sprouts! 25:00 The resistances measured from these lettuce seedlings is in the Mega-Ohm range (1000000 Ohms), so the measurements suggest the plants are insulators. 26:50 Cameron has some problems with the methods of making contact to the plant. 27:50 we mixed up the units, Distilled water is 0.2 MOhm-meters, while DI water is 15MOhm-cm, so the distilled water is really only 0.002MOhm-cm, much lower than the resistivity measured. 42:15 This paper (also from the arXiv) is titled “Green tea induced gold nanostar synthesis mediated by Ag(I) ions” 43:35 They use Green Tea to reduce Silver Nitrate which then helps the formation of gold nanostarts that nucleate on the Silver ion 47:00 Gold nanostars are useful for photonic applications (LEDs, photovoltaic/solar materials, like Quantum Dots), drug delivery (where we can put drugs on or inside the nanoparticle, then functionalize the material to only attach to certain cells, and then deliver drugs directly where we want to in the body), and cancer imaging (where cancer cells will uptake more nanoparticles and then they are easy to image using Near-Infrared radiation. 52:30 I asked @thecollapsedpsi on twitter, and @murphyslab responded to say that citrate is often used to reduce Au3+, so they think it is likely that green tea could be used. Thanks for the quick answers! 54:20 what were their motivations for even trying green tea? they mention it is a “green” process and “non-toxic” but we don’t really buy the non-toxic argument without more analysis. 58:00 Thanks to Alfonso for leaving us a rating on iTunes and a comment on the website ! Instead of being topically relevant, the music this week are songs we mentioned/sung during the recording. Intro: Open – Crying ( Get Olde ) Intermission – Monty Python’s Holy Grail Super Rad – The Aquabats! Outro: Dreams are Maps – The Wild ( Dreams are Maps )…

LASER: Materials Science Podcast

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Episode 10 – Perovskites, Gold, and 3-D Metal Printing 1:05:31

11 years yang lalu1:05:31

1:05:31

Source: Michigan Tech News This week on LASER we discuss Perovskite solar cells with organic charge transport layers, the horrible health effects of illegal backyard gold ore refining in Indonesia, and a new free open source metal 3-d printer from Michigan Tech. This show is also the first one we ever recorded entirely over the internet. 1:30 introductions for our first online-only show! (we’ve always done them at least partially in person before.) 3:00 Perovskite Solar Cells Employing Organic Charge Transport Layers. published in Nature Photonics http://www.nature.com/nphoton/journal/vaop/ncurrent/full/nphoton.2013.341.html 4:00 Perovskite solar cells are important because of their high carrier mobilities (the electrons and holes can more more easily) This is pretty tough to describe in podcast, but Chris gives it a try. A few leading questions help out. 7:00 we want organic solar cells because they can be wavelength tuned and still be transparent, so your windows could turn IR or UV light into energy, while letting visible light pass through. 9:40 we discuss Multi-junction solar cells that are used to overcome the shockley-queisser limit that defines “maximum” solar cell efficiency (~33% for Silicon) https://en.wikipedia.org/wiki/Shockley-Queisser_limit 13:15 Chris’s research is into making a better buffer layer for organic charge transport layers. We trick him into explaining this. 14:45 When are we going to record that special episode explaining photovoltaics? it should be soon… 21:00 after an awkward transition, we end up in Indonesia, discussion small scale (backyard) gold ore refining, and its horrible environmental impacts. From THIS NY Times article http://www.nytimes.com/2014/01/03/business/international/small-scale-gold-mining-pollutes-indonesian-lands.html?partner=rss&emc=rss&_r=1 22:20 we explain the scheme for Mercury amalgam gold ore refining (which was a process used for a few hundred years–we didn’t find a source for the origin) 24:30 Mercury toxin is where the phrase “mad as a hatter” comes from. It also kills people by affecting your CNS, and causes serious birth defects and infertility. 31:00 Chase explains the modern process for Gold cyanidization process. This is a common modern practice for gold ore refinement, started in 1887, and has caused a lot of environmental contamination around California, where it was used following the gold rush. Even with cyanide, it is considered safer than the mercury process. 33:00 we really should have studied our chemistry before describing the process… sorry! 36:30 chase gets indignant about “who needs gold other than scientists?!” 37:00 we should add that “78% of the gold consumed each year is used in the manufacture of jewelry.” (via http://geology.com/minerals/gold/uses-of-gold.shtml) 38:40 Chris didn’t talk much during this because of he was so emotional for the plight of the Indonesians exposed to the mercury. 40:00 Metal 3-d printing! This paper is open source, so its free to read, and it describes how to build their printer! https://www.academia.edu/5327317/A_Low-Cost_Open-Source_Metal_3-D_Printer 10.1109/ACCESS.2013.2293018 41:50 based on the open source reprap 3-d printers (http://www.reprap.org/wiki/RepRap). 43:00 the deposition used is a gas metal arc welder instead of the usual stock extrusion tube. 45:47 the inside areas of the part were much softer than the outside because of the additive manufacturing technique. 49:30 the 3-D printed GUN controversy! (these still wouldn’t hold up to repeated use, so not more useful than a homemade pipe gun) 52:45 we wrap up the metal 3-d printer and our plans for how to use these in the future, and apparently Chris would 3-d print a counterfeit car. 55:00 we’ve joined the AMAZON ASSOCIATE PROGRAM so before you buy anything on amazon, please use our referral link; it won’t change the purchase price, but we’ll get a small portion back. After the show we talk for a little while about Soylent and its advantages for people working in the lab (How great would it be to be able to work in the lab all the time and not need a lunch break!) and if you want to offer chase a job, email us a contact@laserpodcast.com! Song 1: walkin’ on sunshine Song 2: burl Ives silver & gold…

LASER: Materials Science Podcast

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Short Update & Help LASER! 2:02

11 years yang lalu2:02

2:02

Just a quick update about our plans for the future, and some begging for ratings and reviews, topic suggestions, and interviews. Now that we’re 10 episodes deep, and finally getting the hang of this podcasting thing, its time to start trying to expand our listener base, and make a couple changes to the show. We’re going to start recording short pieces trying to explain specific topics or experimental techniques in materials science & engineering. We would also like to start inviting people involved in interesting things onto the show, and discussing with them. So please help us out by leaving a rating and review, telling people about us, and if you are doing something interesting or know somebody else who is, please email us at cameron-at-lsaerpodcast-dot-com! Do the same if you have any STEM topic you want us to discuss. Thanks, Cameron…

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