Martin Gardner (October 21, 1914 – May 22, 2010) was an American popular mathematics and science writer who wrote about math puzzles and intellectual recreations in Scientific American for a quarter-century. Despite his lack of formal mathematical training, his column “Mathematical Games” has had a huge impact on the way people view math and engage with mathematical concepts recreationally. Every year on his birthday, mathematicians, scientists, artists and puzzle enthusiasts around the globe gather to honor Gardner’s work with math puzzles, logic puzzles, hexaflexagons and Möbius strips, magic and card tricks and visual paradoxes.

Join Prof. Jenna Frye, our 2018 HEMI/MICA Artist/Designer in Residence, to celebrate Gardner’s legacy by making your own hexaflagons and solving playful puzzles. Feel free to bring a magic trick, puzzle, optical illusion or recreational mathematics problem to share!

A sustainable conversion systems through nano/micro scaled phenomena

In the lecture I will briefly introduce our ongoing research projects relating to electromagnetic, electrochemical, fluid-dynamic and catalytic phenomena for enhancement of transport of energy and molecule using nano-scaled technologies which can be scaled up for macroscopic enhancement of high efficiency energy conversion.

1. Generation of electricity by radiation spectrally-controlled using micro-structured surfaces

We are conducting a research on an electricity generation system using a GaSb semiconductor thermophotovolaic cell. In this case, since the GaSb cell has an active range from visible to 1.8 microns wavelength, spectral control should be required in both cases of far- and near-field radiation. In the case of far-field radiation, microcavity structure is useful from a wave guide theory for metals, while in the case of near-field radiation, a pillar-array structure is useful from an interference and resonance of Surface Plasmon Polariton (SPP).

2. A high power density Solid Oxide Fuel Cell using an anode incorporating Proton Conductor

We are conducting a research on an integrated system between a biomass gasification catalyst reformer with a hydrogen separation film and a solid oxide fuel cell with an anode incorporating proton conductor. The SOFC produces electricity with thermal energy under the condition of an operating temperature around 1000K, while the hydrogen will be produced though endothermic reaction under the condition of thermodynamically-required temperature around 1000K. As a result, an internal reforming system in the SOFC will provide the highest total conversion efficiency. In the case of biomass gasification, only the hydrogen produced in the porous Ni catalyst reformer goes though the separation film made of a thin silica glass and then will be supplied for the SOFC. The reduction of hydrogen concentration leads to advanced progress of reaction to produce hydrogen. On the other hand, in the case of SOFC, a new anode incorporating proton conductor was proposed.

The BCY (Barium Cerium Yttrium oxide) plays an important role of hydrogen adsorption and excellent supply the adsorbed hydrogen into the three phase boundary (TPB). As a result, using the proton conductor, the reaction overpotential (reaction resistnce) was reduced to an almost half of that of the conventional anode SOFC.

3. Development of Diesel Particulate Membrane Filter (DPMF) for zero emission vehicles

We are conducting a research on a Diesel Particulate Membrane Filter (DPMF) and the conventional DPF. The soot filtration efficiency will be almost 100% after soot cake was established on the DPF wall surface. As a result, a membrane made of nano-sized SiC-particles will become an excellent filter even for nano-scaled diesel particulates. In addition, a thin oxide layer on the surface of SiC nanoparticle plays an important role on oxygen adsorption. The adsorbed oxygen was reacted with soot under the condition of a lower temperature than that for the conventional DPF. Moreover, including a single-nano-scaled Platinum particle in the oxide layer, the oxidation temperature becomes lower.

Using the DPMF, a zero emission vehicle will be achieved in near future.

——-

Katsunori Hanamura is the professor of School of Engineering, Tokyo Institute of Technology, Japan. He received his Ph. D from Tokyo Institute of Technology in 1991. He started his career as the research associate in Department of Mechanical Engineering, Tokyo Institute of Technology in 1984 and was promoted as the full professor in 2003. Prof. Hanamura’s research interests are primarily focused on thermal engineering, near-field radiation transfer, SOFC and biomass gasification. He is the leader of JST national program on phase interface science for highly efficient energy utilization. (http://www.mep.titech.ac.jp/~TANSO/hanamura/e_framepage/index-j.htm)

Projects in Additive Manufacturing and Charged Polymers at ARL

Additive Manufacturing (AM) processes are revolutionizing the on-demand capabilities of current front-line missions for the modern soldier, allowing unprecedented levels of manufacturing versatility and multi-functionality as needed. As the technology continues to mature, new materials and methods for evaluating AM parts will be required. In this seminar, a variety of important topics related to polymer additive manufacturing at the US Army Research Laboratory are discussed, including applications in the areas of: recycling of front-line battlefield polymer waste for on-demand AM, fabrication of novel filaments for AM processes, and construction of nanocomposites using AM. Techniques for evaluating mechanical performance of AM polymers are also discussed, including topics in the areas of interfacial mechanical behavior and fracture properties.

Nikki Zander, Dan Cole, Kevin Hart, and Frank Gardea from the Army Research Lab will be joining us at the Johns Hopkins University Homewood Campus. Seminar will be held at 11 AM in Malone Hall, G 33/35.

Foldable and Responsive Soft Metamaterials

Shu Yang
Department of Materials Science and Engineering, University of Pennsylvania

Materials that can expand and collapse, fold, and transform into a variety shapes have attracted significant interest and have obvious applications in flexible electronics, color displays, smart windows, actuators, sensors, and both photonic and phononic devices. But how can we render a rigid device super-flexible so that it can wrap around a sphere without bending and stretching? How can flat surfaces be transformed into any desired 3D structure without disruptive stretching and deformation?
In my talk, I will show several examples how we introduce holes and cuts in periodically structured materials, so called metamaterials, exhibiting dramatic shape change (e.g. ~800% areal expansion) and super-conformability via expanding or collapsing of the periodic hole arrays without deforming individual lattice units. When choosing the cuts and geometry correctly, we show folding into the third dimension, known as kirigami. The kirigami structures can be rendered pluripotent, that is changing into different 3D structures from the same 2D sheet. We then pre-program the buckling direction and curvatures by introducing notches on existing kirigami structures or by embedding cues in surface patterns of liquid crystal elastomers with internal strains. Lastly, I will show our initial success in additive manufacturing toward textile based self-folding devices.

Seminar will be held at 3:30 PM in Malone Hall G 33/35.

Development of Micro-Architected Materials for Space Propulsion and Pulsed Power Applications

Nasr M. Ghoniem, University of California, Los Angeles

Advances in electrode, chamber, and structural materials will enable breakthroughs in future generations of electric propulsion and pulsed power (EP & PP) technologies. Although wide ranges of electric propulsion and pulsed power technologies have witnessed rapid advances during the past few decades, much of the progress was based on empirical development of materials through experimentation and trial-and-error approaches. To enable future technologies and to furnish the foundations for quantum leaps in performance metrics of these systems, a science-based materials development effort is required. We aim to develop new plasma-resilient material architectures that will enable future generations of electric propulsion and pulsed power technologies through an integrated research approach that combines multiscale modeling of plasma-material interactions, experimental validation, and material characterization. The range of materials of interest in EP & PP include refractory metals, such as tungsten and its alloys (W-Re) and molybdenum, ceramic composites, such as BN and Al2O3, high-strength copper alloys, and carbon-carbon composites. These classes of materials serve various design functions; primarily in cathode and anode applications, in accelerator grids, and in beam dumps of HPM sources. The presentation will give a review of our fundamental understanding for the limits of using these materials in EE & PP, and the opportunity to design material architectures that may dramatically improve their performance. We discuss the results of recent research related to three questions: (1) How can we control the thermomechanical response of materials in extreme heat flux and mitigate failure? (2) What are the phenomena that determine the unstable erosion of material surfaces in plasma and ion environments? and (3) How can we design materials that beneficially influence the plasma through Secondary Electron Emission (SEE)? We first review the status of our experimental facilities for simulation of the space environment. Then, we present results of our understanding of the thermomechanics of materials in severe pulsed plasma environments, and the factors that control the erosive instabilities of surfaces. Finally, results of the effects of surface architectures on secondary electron emission will be given.

Seminar will be held at 11:00 AM in Malone Hall, G33/35.

Dynamic Behavior of Earth Materials Subjected to Pressure-Shear Loading

Dr. John Borg, Prof. of Mechanical Engineering, Marquette University

The dynamic behavior of earth materials, such as wet and dry sand, is of interest to a variety of research fields such as defense, mining and planetary science. Plane-strain experiments are necessary to obtain the Hugoniot response of such systems however such loading is not indicative of most loading scenarios of interest.  Thus understanding oblique impact configuration (pressure-shear) can lead to a better understanding of the role of strength in the dynamic response of earth materials.  Figure 1 illustrates the basic configuration of the impact experiment and sand of interest.  A key aspect of this experiment is obtaining an accurate measurement of the normal and transverse velocity of the anvil.  For these experiments a photon Doppler velocimetry (PDV) will be used.  The configuration and the inherent difficulties of applying such a diagnostic technique to this experiment will be discussed.

Seminar will be held at 3:30 PM in Malone G33/35.

Fig. 1. (a) Oblique impact configuration with assembly with a thin sand sample with incident and reflected probes (b) Oklahoma #1 pure sand (425 – 500 μm diameter)