The painful and debilitating effects of osteoarthritis at the knee can be remedied by replacing the damaged articulating surfaces of the kne...
The painful and debilitating effects of osteoarthritis at the knee can be remedied by replacing the damaged articulating surfaces of the knee with a total knee replacement. Modern knee replacements consist of a metal alloy component on the femoral side (top of the knee) and a special plastic called ultra-high molecular weight polyethylene on the tibial side (bottom of the knee). Through recent improvements in materials, these implants have seen increased longevity, often lasting 15 years or more in the body before requiring a second surgery. As patients opt for knee replacements earlier in life, remain more active after surgery and live longer, the demands on the design and longevity of knee replacements increases.nnOne of the leading causes of revision surgery is periprosthetic bone loss, which means that bone near the implant has thinned. As the knee articulates during walking, the top metal component slides, rolls and rotates on the polyethylene. This relative motion causes the polyethylene to wear. Microscopic debris leaves the surface and enters the surrounding tissue, where it can set off a cascade of cellular reactions that lead to bone resorption. Currently, knee replacement designs and materials are evaluated before being implanted by machines that run accelerated tests by simulating the motion of walking at the knee.nnHowever, walking is not the only activity of daily living. Sitting in a chair, rising from a chair, stepping up a stair and stepping down a stair are the most common activities for total knee replacement patients after walking. In a motion analysis lab, we measured the movements and dynamics of these activities using retroreflective markers, infrared cameras and force plates. Using a computational method known as inverse dynamics and a parametric numerical model, we were able to show that these activities generally have larger motions and higher forces. In particular, the secondary motions of the knee, such as internal-external rotation and medial-lateral (side-to-side) translation, are often larger in non-walking activities.nnUltra-high molecular weight polyethylene, the plastic most commonly used in knee replacements, is made of long chains of molecules. The material is highly wear resistant because the chains are entangled. As thousands of cycles of walking accumulate, the molecular chains align in the primary direction of motion. Once aligned, the material is more susceptible to wear in secondary directions. The larger secondary motions of other activities could lead higher wear. Because pre-implantation tests only include walking, the tests may be insufficient to accurately predict the wear of the implant in the body.nnCurrently, testing is underway to evaluate if the motions of non-walking activities do increase the wear of knee replacements. In addition, knee replacements that had been implanted and were retrieved from patients after revision surgery or death are being evaluated for wear. The results of these retrieved specimen will help determine whether the inclusion of non-walking activities in testing routines is necessary to evaluate the wear of total knee replacements.nnMy dance to explain my in-progress PhD thesis was originally choreographed for live performance and adapted for the camera. Less
The sun creates a lot of energy by hydrogen fusion. Scientists are investigating fusion, building our own ‘sun on earth’, as a sustainab...
The sun creates a lot of energy by hydrogen fusion. Scientists are investigating fusion, building our own ‘sun on earth’, as a sustainable energy source on earth. A lot of energy is released when hydrogen isotopes fuse together into helium and neutrons. One of the key problems is that these high energy neutrons can damage the crystal structure of the surrounding tungsten wall. This can create vacancies in the metal lattice, which trap hydrogen atoms. Trapped hydrogen cannot fuse to release energy.nnMaterial temperature turns out to be an important factor in managing hydrogen capture. We investigated how hydrogen can escape if the tungsten material is hot. On the one hand, hot tungsten atoms are more mobile and can move back into vacancies in the crystal, so that the metal effectively heals itself. Additionally, the hydrogen atoms themselves have a higher mobility at a high temperature. They can now escape from their captivity and take part in the fusion process within the heart of the machine; one step closer to creating a sun on earth.nnMy PhD dance is performed around and on the experiment I’m using for my research, Magnum-PSI (FOM Institute DIFFER, the Netherlands). Magnum-PSI is capable of reproducing the conditions that we expect in the wall of a fusion reactor. We can therefore test materials on their capabilities of withstanding such a harsh environment.nnI would like to thank all people that helped me create this dance. We had an incredible amount of fun using the experimental hall in the weekend for a completely different purpose than the usual experiments. Special thanks to FOM Institute DIFFER (www.differ.nl).nnExplanation of my PhD dance in detail:nThe two dancers at the platform on top of the machine illustrate the fusion of two hydrogen atoms (yellow dresses) into helium within the sun. An abundance of energy is released in this way. Looking down from the machine, we see a single hydrogen atom ‘on earth’. Her movements are the same as in the duet, however much smaller. She dances alone to show that when too much hydrogen is captured in the surrounding wall of a fusion reactor, there is not enough hydrogen to keep the fusion process going.nIn the following scene, we see the regular structure of a tungsten material, depicted by the disks on the ground and the three dancers (black dresses). Smoke rings illustrate the high energy neutrons that, released in the fusion reaction, continuously bombard the material. An interaction between neutrons and the tungsten materials will not happen often, but when it does it will cause a chain reaction of displacements in the material; the frisbees move in all directions. nAt low surface temperature (blue light), the hydrogen atoms are more easily trapped and hence can no longer take part in a fusion reaction. The yellow dancers are captured in the material, they join in on the movements of the black dancers.n At high surface temperatures (red light) the hydrogen atoms have a higher mobility, which prevents them from getting trapped within the material. Their movements are wider and more energetic. Additionally, the material itself regenerates. The disks return to a regular structure, limiting the number of vacancies in which hydrogen can be captured. Now liberated, the yellow hydrogen atoms escape and dance away from the material. n The dance continues with a duet of hydrogen atoms entangled in a fusion reaction. We end back in the original scene, but this time with two fusion duets; one in the sun (on top of the machine), the other within a fusion reactor (on the floor). Less
My PhD research was on studying pairs of heavy-element reactions to see if there was a better way to make these isotopes. By shooting an io...
My PhD research was on studying pairs of heavy-element reactions to see if there was a better way to make these isotopes. By shooting an ion beam of a particular energy from an accelerator at a target and measuring the decays of the particular isotope we made in a detector further away, we can determine the reaction probability (cross section) of that reaction. The cross section is a ratio of the production rate of the thing you want to make by the beam dose per unit area by the number of target nuclei per unit area. If you make the same isotope two different ways and one way has a significantly higher cross section, it indicates a favored reaction. In my dissertation research I looked at eight different reactions, or four pairs, making the elements Db, Bh, Mt, and Rg. If you aren’t familiar with those elements, look at the bottom of the transition metals on the periodic table. nnThe cyclotron accelerates beam ions in an outwardly spiraling horizontal path. If you look closely you can see that the beam ball color and the target hoop color are combined in the hoop color of the product atom, most of the time. (I didn’t have any white LED beam balls.) I used t-shirts of different colors with their element symbols to show that the combination of the beam ball and target hoop made something completely different. The product atom recoils out of the target and travels along with unreacted beam and gets separated along the way to the detector. The decaying atom of Mt first undergoes alpha decay by getting rid of the yellow ball. The so-called “daughter” product Bh also decays by alpha emission to Db, but the Db atom grabs a red ball representing an electron and turns into Rf. This isotope of Rf spontaneously fissions – or splits in two – and that ends the decay chain. I used this same kind of experimental method to discover the new isotope 260Bh, which is so awesome I had to use fire to represent it.nnYou see eight “data points” towards the end of the video but I only list five reactions plus the new isotope because those are the ones I did myself. The other three data points were added to my results from a thorough meta-analysis of the literature. The short answer to the question of “is there a favored reaction method?” is NO. The statistical uncertainty in the cross sections of each reaction pair overlap, represented at the end by the rotating hoops.nnThanks for watching! Less
Quick Key:nNavy: electrons (e-)nBlue/Orange: ferrocenium / ferrocene (Fcn+/ Fcn)nRed: lithium ions (Li+)nYellow: solvent (Sol)nnnSide reacti...
Quick Key:nNavy: electrons (e-)nBlue/Orange: ferrocenium / ferrocene (Fcn+/ Fcn)nRed: lithium ions (Li+)nYellow: solvent (Sol)nnnSide reactions in lithium-ion batteries are a major problem for battery safety and lifetime. My research tries to determine what these side reactions are and how to control them. To do this, I developed a new method to characterize side reactions by using the molecule ferrocene. When ferrocene is in its reduced (electrically neutral) form, it is orange. When it is in the oxidized (positively charged) form, known as ferrocenium, it is blue-green.nnThe main reaction in this system is the reduction of lithium ions (red dancers). When lithium ions are reduced by electrons (navy blue dancers), the resulting lithium intercalates into the electrode. However, solvent molecules (yellow dancers) are reduced at the same potential. The insoluble solvent reduction products precipitate as a film on the electrode surface. This film passivates the electrode, blocking further reaction. nnSolvent reduction is much more complex than the single-electron reaction shown here, and the properties of such thin films are hard to measure. To better understand the films, we add ferrocenium (blue dancer). Because ferrocenium reduction occurs at a different potential than lithium or solvent reduction, its rate is much easier to measure. As the film grows thicker and less porous, through-film ferrocenium reduction becomes more difficult. This method can thereby determine film parameters such as the thickness and porosity.nnThis dance was performed with the help of Lindy on Sproul, our campus swing dance club. The song, "What'cha Know Joe?", reflects both the poorly-understood nature of side reactions and the mental state frequently experienced during a Ph. D. Less
I created this video for the competition "Dance Your PhD," sponsored by Science and TED. nnThe aim of the contest is to get scientists to cr...
I created this video for the competition "Dance Your PhD," sponsored by Science and TED. nnThe aim of the contest is to get scientists to creatively explain their PhD theses through dance. I have a second goal, which is to show what "math research" means (since many people think it means looking up formulas in books).nnIn the first minute of this video, the dancer (Libby) shows how two pentagons are glued together to make a surface. This is the key idea of the video -- the explaining of science, wordlessly, through dance. You will understand it, and you will remember it. This is my favorite part!nnOkay, now step back for a minute. Imagine that you are walking in a straight line on a bagel. Maybe you walk right through the hole, and return back to where you started. Maybe you walk around the outside (like an equator), and return back to where you started. Or maybe you walk in a spiraling path (still in a straight line), through the hole and around the bagel a few times before returning to where you started.nnIn the next part of the video, Libby dances across the pentagon in a straight line. This is exactly like your spiraling walk on the bagel: she dances in a straight line, and goes around the surface a few times (maybe 8, because there are 8 lines on the pentagons) before she returns to where she started and repeats the path.nnWhen Libby dances across the pentagons in straight lines, she dances across the colored edges of the pentagons. We care about which ones she crosses, so we keep track of it by having a Math Hatter with that color shirt get in line. This creates a sequence of colors (which repeats with period 8).nnMy thesis investigates what happens to this color sequence when we change the pentagon surface. We "shear, cut and reassemble the pentagons," which is clearly shown in the video. This changes the original 8 lines on the pentagons to a different pattern -- 4 lines, as it turns out. When Libby dances across these four lines, she's doing a different, shorter spiral around the bagel (if you will). She crosses four colored edges, which gives us a new sequence of Math Hatters. Thesis question: What is the relationship between the 8-color sequence and the 4-color sequence?nnAnswer: Each Math Hatter checks to see if s/he has the same color on both sides, and if so, stays in line (keeps her hat), and if not, sadly has to leave (removes his hat).nnThat's my theorem: Shearing and reassembling the pentagons is equivalent to seeing if the colors are the same on both sides. nnMost videos submitted to this contest use metaphor: "I study titanium bonding to bone, which is kind of like titanium and bone dancing together." I am fortunate that I can show you the actual objects (shapes and lines) that I study, and explain the actual result I proved in my thesis.nnThanks for watching, and for reading this explanation.nnHere is the FAQ about how I created this video: https://vimeo.com/47273811nnThis video has been shown at:n- the AMS Math Research Community at Snowbird, UTn- the Summer@ICERM REU, Brown Universityn- the Anja S. Greer Math Conference at Phillips Exeter AcademynnAlso seen on:n- Reddit: http://www.reddit.com/r/math/comments/vx3wt/cutting_sequences_on_the_double_p...n- PhD + epsilon: http://blogs.ams.org/phdplus/2012/08/31/performance-math/n- Brown Daily Herald: http://www.browndailyherald.com/grad-student-illustrates-math-thesis-through-dance-1.2774229#n- BDH article (essentially) reported In Russian: http://blog.campus-online.ru/?p=1800n- The Aperiodical: http://aperiodical.com/2012/07/dance-your-phd-cutting-sequences-on-the-double...n- Math Munch: http://mathmunch.wordpress.com/2012/07/09/faces-blackboards-and-dancing-phds/n- AMS Graduate Student Blog: http://mathgradblog.williams.edu/dance-math-phd/n- howthebodyworks: http://howthebodyworks.org/post/30128065018/dance-your-thesis-by-diana-davis-is-the-firstn- Williams math headlines: http://math.williams.edu/diana-davis-07-phd-dance-video/n- Brown math headlines: http://www.math.brown.edu/nnIf you have read this far and you want to read the actual paper for which this video serves as a sort of abstract, here it is: http://www.math.brown.edu/~diana/math/VeechPolygons.pdfnYou can write to me at diana(at)math.brown.edu. Less
*** WINNER OF THE 2012 DANCE YOUR PhD COMPETITION ***nnSydney University researcher, Peter Liddicoat, has won the 2012 Dance Your PhD compet...
*** WINNER OF THE 2012 DANCE YOUR PhD COMPETITION ***nnSydney University researcher, Peter Liddicoat, has won the 2012 Dance Your PhD competition (run by Science magazine). Watch his winning video where he translates his PhD research in materials science into dance.nnAnnouncement of contest winners: nhttp://news.sciencemag.org/sciencenow/2012/10/dance-your-phd-and-the-winner-is.html?ref=hpnnMore information about the competition: http://gonzolabs.org/dance/nn------------------------------------------------------------------nnTitle: "A super-alloy is born: The romantic revolution of Lightness & Strength"nn"It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness" -- surely Charles Dickens was describing life as a PhD student? Through interpretive dance, we've tried to communicate the circus that is a PhD experience.nnOur story introduces the Engineer's elusive dream to arrange the coupling of Lightness and Strength - a classic engineering romance over the ages. Strength is heavy and difficult to work with, Lightness is delicate and frail.nnThe Engineer summons the Scientist and explains the problem. This is a daunting task. Inspired by the Engineer, the Scientist uses a sophisticated atom probe microscope to observe, at the atomic level, what makes Lightness so frail. He finds that when force is applied to the perfect crystal structure of Lightness the bonds break and the atoms slip along a straight line. But how to make it stronger? Could the lines of atoms be arranged so that they didn't slip?nnTaking an unconventional route, The Scientist tries a process of applying torsion to redesign the atomic architecture. He applies this revolving force to the crystal, dividing it into multiple smaller parts, and creates interfaces that might block slip. Alloying atoms are arranged on the interfaces to provide important adhesion between the small crystals. Nervously, the Scientist tests this new design and discovers the new material resists much greater force without breaking. This new material is a light-weight aluminium alloy with the strength of heavy steel, a new world record!nnThe Engineer evaluates the new Super-Alloy. It performs fantastically! The Engineer thanks the Scientist and carries the Super-Alloy off into the sunset.nnFor further info, please see:nnWhat is an atom probe microscope? What is atom probe tomography?nhttp://youtu.be/kjBkh091LG8nn"Nanostructural hierarchy increases the strength of aluminium alloys"nLiddicoat, P.V., Liao, X.Z., Zhao, Y., Zhu, Y.T., Murashkin, M. Y., Lavernia, E. J., Valiev, R. Z., Ringer, S.P.nNature Communications, 2010, Volume 1, Issue 6, p. 63-69nn"Nanostructures give alloy super strength"nAMMRF Media Release, 2010nhttp://ammrf.org.au/012_070910.php Less
The concept of Dynamic Capabilities originates in the Resource Based View of a firm. Resource based approach is relatively static and cannot...
The concept of Dynamic Capabilities originates in the Resource Based View of a firm. Resource based approach is relatively static and cannot fully explain how firms adopt to changing environments. Dynamic Capabilities are the construct that explains this dynamism. Dynamic Capabilities are the capabilities of a firm to rearrange its resources according to the need of the (dynamic) environment. One part of this construct is Dynamic Managerial Capabilities. Routines of a firm provide some abilities of resource reconfiguration (e.g. routine of "Contact with clients" may be fulfilled in different ways according to the situation). But the role of managers is often underestimated. Managers do have influence and not only within routines, but also in breaking existing routines. nThe RBV differs from other economic approaches e.g. by the role of rationality of individuals. Last articles in the field of RBV and Dynamic Capabilities touch upon emotions and incorrectness of "cold cognition" approach. My dissertation might prove the influence of two positive (admiration/inspiration, "fiero"/feeleing of having something done and succeeded) and two negative (fear, anger) emotions onto dynamic managerial capabilities. nI have generalized my hypotheses for this contest. In my dissertation I´ll try to split Dynamic Managerial Capabilities into capacities of Sensing of opportunities and threats, Seizing of opportunities, and Reconfiguration of resources. Thus every of the named in my video hypotheses will be split into three sub-hypotheses to check the influence of emotions onto every part of the construct.nIn my video I try to show how the investigation of emotions might influence RBV. I hope emotions would play the same role for RBV as color and visual effects did for film industry in the mid of the last century.nThis video was created together with my friends and colleagues: Maiia Deutschmann, Raphael Jung, and Peggy Zimmer for the contest "Dance Your Ph.D 2012". It was a pleasure for me and, interestingly, some of the ideas for my dissertation were born during the communication with my friends while making this video.nI appreciate Gonzolabs and Vimeo for this fascinating opportunity! I also appreciate the European University Viadrina (Frankfurt a.d. Oder), the German Graduate School of Management and Law (Heilbronn), and the Graduate Programme on Dynamic Capabilities and Relationships, which I am a part of. nMy special thanks to the FreeMusicArchive.org and the bands “Dyman” and “The Womb” which share their perfect(!) music and allow the use of it. Less
"Belly Dance/Beyonce style" performed by Miss Varsha (16 years old,Studying in 10+2 and under Phd from Prachin Kala Kendra Chandigarh in BHA...
"Belly Dance/Beyonce style" performed by Miss Varsha (16 years old,Studying in 10+2 and under Phd from Prachin Kala Kendra Chandigarh in BHARATNATYAM IV year) at the time of semi final round in "Dance Jodhpur Dance season-2" program age group 15 to 25 organised by Rajan Amplifier at Aiswariya College Jodhpur (Rajasthan) on 21.06.2012 and selected for the grand finale to be held on 1st July 2012 in Mahavir Complex Jodhpur and Judge by Mr.Terrence Lewis sir. She was participating IInd time in the season one also up to final round in junior group please give your support for final and sponsor for her bright future. Less
TV talent show audition secrets WEDNESDAY OCTOBER 31, 2012 / 10:30 - 13:30 / PRINCE OF WALES THEATRE, LONDON For more information or to book...
TV talent show audition secrets WEDNESDAY OCTOBER 31, 2012 / 10:30 - 13:30 / PRINCE OF WALES THEATRE, LONDON For more information or to book visit: bit.ly Donna Soto-Morettini CASTING DIRECTOR & PERFORMANCE COACH Donna Soto-Morettini worked for many years as a professional singer and actress, in Southern California and throughout the western United States. She holds a PhD from Oxford University, and has been training professional actors and singers for 20 years. She has served as Director of Drama for the Royal Scottish Conservatoire, Head of Acting and Dance for Liverpool Institute for Performing Arts, and Head of Acting at the Central School of Speech and Drama in London. Since 2007 she has worked as a Casting Director and Performance Coach for television, and credits include How Do You Solve a Problem like Maria, Any Dream Will do, I'd Do Anything, Over the Rainbow (BBC), Popstar to Operastar, Superstar (ITV), and The Voice (BBC). She is the author of Popular Singing, The Philosophical Actor (winner of the Choice Award for Outstanding Academic Title 2011) and her book, Mastering Auditions: How to Perform Under Pressure will be published by Methuen in September. Less
Artist: DJ Husband Label: PHD Pure Hard Dance Digital Recordings Genre: Hard Dance (German Trance, Hard Trance) Release Date: October 22, 20...
Artist: DJ Husband Label: PHD Pure Hard Dance Digital Recordings Genre: Hard Dance (German Trance, Hard Trance) Release Date: October 22, 2012 Catalogue No: PHD018 Length: 7:00 Purchase Link: www.trackitdown.net Less
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