The study of those aspects of energy and matter in terms of elementary principles and laws. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
1Department of Quantum Science, The Australian National University
This is an instructional paper to guide the construction and diagnostics of external cavity diode lasers (ECDLs), including component selection and optical alignment, as well as the basics of frequency reference spectroscopy and laser linewidth measurements for applications in the field of atomic physics.
Published April 24, 2014. Keywords: Physics, External Cavity Diode Laser, atomic spectroscopy, laser cooling, Bose-Einstein condensation, Zeeman modulation
The field of quantum optics rests on the work of Roy Glauber, who helped elucidate the nature of light as both particles and waves. In this candid interview, the Nobel prize-winning physicist shares his thoughts about this strange and unintuitive behavior of light, balancing fatherhood with an academic career, and working at Los Alamos National Laboratory, where he shockingly learned that he was helping to build The Bomb.…
Published June 26, 2009. Keywords: Physics, Quanum Optics, Light, Wave Particle Duality, Los Alamos, Lindau, Nobel Laureate
Theodor Hänsch was a co-recipient of the 2005 Nobel Prize in Physics for "contributions to the development of laser-based precision spectroscopy, including the optical frequency comb." In this video, Hänsch explains "in a nutshell" the frequency comb, its theories, its many applications, and the breakneck pace of the research leading up to the Nobel Prize.
Published July 13, 2009. Keywords: Physics, Nobel Laureate, Laser-Based Spectroscopy, Frequency Comb, Atomic Clocks, Quantum Optics,
At extremely low temperatures, the molecules of certain fluids are able to flow without internal friction or resistance - a phenomenon know as superfluidity. In this interview, Nobel Laureate Douglas Osheroff (Physics 1996) describes the somewhat arduous quest to prove the predicted superfluid state of helium-3. He also shares his thoughts on mentoring undergraduates and his philosophy on getting the most out of graduate school.…
Published July 7, 2009. Keywords: Physics, Nobel Laureate, Douglas Osheroff, Superfluidity, Helium-3, Superconductivity
1Department of Physics and Astronomy, University College London, 2CERN, 3Physics Division, Lawrence Berkeley National Laboratories
This paper demonstrates a protocol for recasting experimental simplified model limits into conservative and aggressive limits on an arbitrary new physics model. Publicly available LHC experimental results can be recast in this manner into limits on almost any new physics model with a supersymmetry-like signature.
Published November 15, 2013. Keywords: Physics, high energy physics, particle physics, Supersymmetry, LHC, ATLAS, CMS, New Physics Limits, Simplified Models
1Chemical and Biomolecular Engineering Department, University of Houston
Confocal microscopy is used to image quiescent and flowing colloid-polymer mixtures, which are studied as model systems for attractive suspensions. Image analysis algorithms are used to calculate structural and dynamic metrics for the colloidal particles that measure changes due to geometric confinement.
Published May 20, 2014. Keywords: Chemistry, confocal microscopy, particle tracking, colloids, suspensions, confinement, gelation, microfluidics, image correlation, dynamics, suspension flow
1School of Physics and Astronomy, University of Leeds, 2Institute of Materials Research, University of Leeds, 3School of Chemistry, University of Edinburgh, 4Department of Chemical Engineering, Northeastern University, 5Department of Physics, Northeastern University
A method to prepare epitaxial layers of ordered alloys by sputtering is described. The B2-ordered FeRh compound is used as an example, as it displays a metamagnetic transition that depends sensitively on the degree of chemical order and the exact composition of the alloy.
Published October 5, 2013. Keywords: Physics, Sputtering, epitaxial growth, magnetism, ordered alloys
1MESA+ Institute for Nanotechnology, University of Twente
Procedures are outlined to prepare segmented and coaxial nanowires via templated electrodeposition in nanopores. As examples, segmented nanowires consisting of Ag and ZnO segments, and coaxial nanowires consisting of a TiO2 shell and a Ag core were made. The nanowires were used in photocatalytic hydrogen formation experiments.
Published May 2, 2014. Keywords: Physics, Multicomponent nanowires, electrochemistry, sol-gel processes, photocatalysis, photochemistry, H2 evolution
1Center for Free-Electron Laser Science, CFEL, DESY, 2Department of Physics, University of Hamburg, 3The Hamburg Center for Ultrafast Imaging, University of Hamburg
We present a technique that allows the spatial separation of different conformers or clusters present in a molecular beam. An electrostatic deflector is used to separate species by their mass-to-dipole moment ratio, leading to the production of gas-phase ensembles of a single conformer or cluster stoichiometry.
Published January 9, 2014. Keywords: Physics, Chemical Physics, Physical Chemistry, Molecular Physics, Molecular beams, Laser Spectroscopy, Clusters
1Physical Sciences Division, Pacific Northwest National Laboratory
Soft landing of mass-selected ions onto surfaces is a powerful approach for the highly-controlled preparation of novel materials. Coupled with analysis by in situ secondary ion mass spectrometry (SIMS) and infrared reflection absorption spectroscopy (IRRAS), soft landing provides unprecedented insights into the interactions of well-defined species with surfaces.…
Published June 16, 2014. Keywords: Chemistry, soft landing, mass selected ions, electrospray, secondary ion mass spectrometry, infrared spectroscopy, organometallic, catalysis
1Faculty of Physics and Earth Sciences, University of Leipzig
Nuclear magnetic resonance is one of the most important spectroscopic tools. Here, the development of a new approach under high pressure, currently up to 10.1 GPa, is presented. This opens a new window into condensed matter physics and chemistry, where high-pressure research is of great importance.
Published October 10, 2014. Keywords: Physics, NMR, micro-coil, anvil cell, high pressures, condensed matter, radio-frequency
1Department of Physics and Astronomy, Michigan State University, 2Department of Chemistry & Biochemistry/Physics, Mercyhurst University, 3Department of Physics, Saint Louis University, 4Department of Physics, Massachusetts Institute of Technology
Scanning-probe single-electron capacitance spectroscopy facilitates the study of single-electron motion in localized subsurface regions. A sensitive charge-detection circuit is incorporated into a cryogenic scanning probe microscope to investigate small systems of dopant atoms beneath the surface of semiconductor samples.
Published July 30, 2013. Keywords: Physics, Biophysics, Molecular Biology, Cellular Biology, Microscopy, Scanning Probe, Nanotechnology, Physics, Electronics, acceptors (solid state), donors (solid state), Solid-State Physics, tunneling microscopy, scanning capacitance microscopy, subsurface charge accumulation imaging, capacitance spectroscopy, scanning probe microscopy, single-electron spectroscopy, imaging
1Physics Department, The University of Texas at Dallas, 2The NanoTech Institute, The University of Texas at Dallas, 3Department of Applied Physics, Aalto University School of Science
A method of fabricating, in ambient conditions, organic photovoltaic tandem devices in a parallel configuration is presented. These devices feature an air-processed, semi-transparent, carbon nanotube common cathode.
Published November 5, 2014. Keywords: Physics, Organic Photovoltaic, Carbon Nanotubes, Ionic Liquid, Tandem Photovoltaic, Conjugated Polymers, Ambient Processing
1Department of Physics, University of Alberta
Fluorescent-core microcavity sensors employ a high-index quantum-dot coating in the channel of silica microcapillaries. Changes in the refractive index of fluids pumped into the capillary channel cause shifts in the microcavity fluorescence spectrum that can be used to analyze the channel medium.
Published March 13, 2013. Keywords: Physics, Microfluidics, Optics, Quantum Dots, Optics and Photonics, fluid flow sensors (general), luminescence (optics), optical waveguides, photonics, condensed matter physics, microcavities, whispering gallery modes, refractometric sensor, fluorescence, microcapillary, quantum dots
1School of Physics and Astronomy, University of Birmingham
Large laser-interferometers are being constructed to create a new type of astronomy based on gravitational waves. Their sensitivities, as for many other high-precision experiments, are approaching fundamental noise limits such as the atomic vibration of their components. We are pioneering technologies to overcome these limits using novel laser beam shapes.
Published August 12, 2013. Keywords: Physics, Optics, Astronomy, Astrophysics, Gravitational waves, Laser interferometry, Metrology, Thermal noise, Laguerre-Gauss modes, interferometry
JoVE Immunology and Infection
1Microbiology Unit, Department of Biochemistry, University of Oxford, 2Biological Physics Research Group, Clarendon Laboratory, Department of Physics, University of Oxford
Photoactivated localization microscopy (PALM) combined with single-molecule tracking allows direct observation and quantification of protein-DNA interactions in live Escherichia coli cells.
Published March 10, 2014. Keywords: Immunology, Super-resolution microscopy, single-particle tracking, Live-cell imaging, DNA-binding proteins, DNA repair, molecular diffusion
1Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 2Electrical Engineering and Computer Science, University of Michigan, 3Biomedical Engineering, University of Michigan
Parametric optomechanical excitations have recently been experimentally demonstrated in microfluidic optomechanical resonators by means of optical radiation pressure and stimulated Brillouin scattering. This paper describes the fabrication of these microfluidic resonators along with methodologies for generating and verifying optomechanical oscillations.
Published May 29, 2014. Keywords: Physics, Optomechanics, Radiation pressure, Stimulated Brillouin scattering (SBS), Whispering gallery resonators (WGR), Oscillators, Microfluidics, Nonlinear Optics
1Department of Physics, University of Notre Dame, 2Department of Chemical and Biomolecular Engineering, University of Notre Dame, 3Center of Functional Nano-Ceramics, National University of Science and Technology, "MISIS"
This protocol describes the preparation of gasless nanostructured energetic materials (Ni+Al, Ta+C, Ti+C) using the short-term high-energy ball milling (HEBM) technique. It also describes a high-speed thermal imaging method to study the reactivity of mechanically fabricated nanocomposites. These protocols can be extended to other reactive nanostructured energetic materials.…
Published April 2, 2015. Keywords: Engineering, Reactive composites, Energetic materials, High-Energy Ball Milling, Gasless Combustion, Ignition, Reactivity Enhancement
1Clarendon Laboratory, Department of Physics, University of Oxford, 2Wellcome Trust Sanger Institute, Genome Center
Studies of biomolecules in vivo are crucial for understanding molecular function in a biological context. Here we describe a novel method allowing the internalization of fluorescent biomolecules, such as DNA or proteins, into living microorganisms. Analysis of in vivo data recorded by fluorescence microscopy is also presented and discussed.
Published February 8, 2015. Keywords: Microbiology, Electroporation, fluorescence, FRET, in vivo, single-molecule imaging, bacteria, Escherichia coli, yeast, internalization, labeled DNA, labeled proteins
1Department of Didactics, Université du Québec à Montréal, 2Department of IT and Tech3Lab, HEC Montreal, 3Department of Marketing and Tech3Lab, HEC Montreal, 4Department of Specialized Education, Université du Québec à Montréal
This paper aims to describe the techniques involved in the collection and synchronization of the multiple dimensions (behavioral, affective and cognitive) of learners’ engagement during a task.
Published July 1, 2015. Keywords: Behavior, Measurement of engagement, learning, neurophysiology, electroencephalography, signal synchronization, electrodermal activity, automatic facial emotion recognition, emotional valence, arousal
1Institute for Solid State Research, IFW-Dresden, 2Institute of Metal Physics of National Academy of Sciences of Ukraine, 3Diamond Light Source LTD, 4Department of Physics, University of Johannesburg, 5CNR-SPIN, and Dipartimento di Fisica "E. R. Caianiello", Università di Salerno, 6Institute of Physics of Complex Matter, École Polytechnique Fédérale de Lausanne
The overall goal of this method is to determine the low-energy electronic structure of solids at ultra-low temperatures using Angle-Resolved Photoemission Spectroscopy with synchrotron radiation.
Published October 9, 2012. Keywords: Physics, Chemistry, electron energy bands, band structure of solids, superconducting materials, condensed matter physics, ARPES, angle-resolved photoemission synchrotron, imaging
1Combustion Research Facility, Sandia National Laboratories, 2Chemical Sciences Division, Advanced Light Source, Lawrence Berkeley National Laboratory, 3Physikalische Chemie I, Universität Bielefeld
Gas sampling from laboratory-scale flames with online analysis of all species by mass spectrometry is a powerful method to investigate the complex mixture of chemical compounds occurring during combustion processes. Coupled with tunable soft ionization via synchrotron-generated vacuum-ultraviolet radiation, this technique provides isomer-resolved information and potentially fragment-free mass spectra. …
Published May 26, 2014. Keywords: Physics, Combustion, Flame, Energy Conversion, Mass Spectrometry, Photoionization, Synchrotron, Hydrocarbon, Soot, Aerosol, Isomer
1Department of Earth Science and Engineering, Imperial College London
We present a methodology for the imaging of multiple fluid phases at reservoir conditions by the use of x-ray microtomography. We show some representative results of capillary trapping in a carbonate rock sample.
Published February 25, 2015. Keywords: Medicine, Reservoir condition, micro-CT, Multi-phase, Carbon Storage, Capillary Trapping, Pore-scale
1Applied Water Physics, Wetsus - Centre of Excellence for Sustainable Water Technology, 2IRCAM GmbH, 3Institute for Thermal Turbomachinery and Machine Dynamics, Graz University of Technology
Horizontal and vertical electrohydrodynamic liquid bridges are simple and powerful tools for exploring the interaction of high intensity electric fields and polar dielectric liquids. The construction of basic apparatus and operational examples, including thermographic images, for three liquids (e.g., water, DMSO, and glycerol) is presented.
Published September 30, 2014. Keywords: Physics, floating water bridge, polar dielectric liquids, liquid bridge, electrohydrodynamics, thermography, dielectrophoresis, electrowetting, Sumoto effect, Armstrong effect
1Department of Electrical and Computer Engineering, Schulich School of Engineering, University of Calgary, 2Department of Radiology, University of Calgary
We demonstrate methods for the detection of architectural distortion in prior mammograms. Oriented structures are analyzed using Gabor filters and phase portraits to detect sites of radiating tissue patterns. Each site is characterized and classified using measures to represent spiculating patterns. The methods should assist in the detection of breast cancer.
Published August 30, 2013. Keywords: Medicine, Anatomy, Physiology, Cancer Biology, angular spread, architectural distortion, breast cancer, Computer-Assisted Diagnosis, computer-aided diagnosis (CAD), entropy, fractional Brownian motion, fractal dimension, Gabor filters, Image Processing, Medical Informatics, node map, oriented texture, Pattern Recognition, phase portraits, prior mammograms, spectral analysis
1Department of Chemical Engineering, Massachusetts Institute of Technology
We present a simple protocol to obtain fluorescence microscopy movies of growing yeast cells, and a GUI-based software package to extract single-cell time series data. The analysis includes automated lineage and division time assignment integrated with visual inspection and manual curation of tracked data.
Published July 18, 2013. Keywords: Microbiology, Cellular Biology, Molecular Biology, Genetics, Biophysics, Saccharomyces cerevisiae, Microscopy, Fluorescence, Cell Biology, microscopy/fluorescence and time-lapse, budding yeast, gene expression dynamics, segmentation, lineage tracking, image tracking, software, yeast, cells, imaging
1Department of Chemical Engineering and Materials Science, University of Southern California, 2Department of Electrical Engineering-Electrophysics, University of Southern California
We describe the use of a carbon dioxide laser reflow technique to fabricate silica resonant cavities, including free-standing microspheres and on-chip microtoroids. The reflow method removes surface imperfections, allowing long photon lifetimes within both devices. The resulting devices have ultra high quality factors, enabling applications ranging from telecommunications to biodetection.…
Published July 2, 2012. Keywords: Materials Science, Chemical Engineering, Physics, Electrophysics, Biosensor, device fabrication, microcavity, optical resonator
1Department of Physics, University of Pittsburgh
Oxide nanostructures provide new opportunities for science and technology. The interfacial conductivity between LaAlO3 and SrTiO3 can be controlled with near-atomic precision using a conductive atomic force microscopy technique. The protocol for creating and measuring conductive nanostructures at LaAlO3/SrTiO3 interfaces is demonstrated.…
Published July 18, 2014. Keywords: Physics, oxide nanostructures; nanoelectronics; semiconductor; LaAlO3/SrTiO3; lithography; AFM nanolithography
1Institute of Biophysics, National Research Council of Italy, 2Dipartimento di Sistemi e Informatica, Università di Firenze, 3Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia
We measured the tension release in an axon that was partially lesioned with a laser dissector by simultaneous force spectroscopy measurement performed on an optically-trapped probe adhered to the membrane of the axon. The developed experimental protocol evaluates the axon adhesion to the culture substrate.
Published May 27, 2013. Keywords: Bioengineering, Biophysics, Neuroscience, Cellular Biology, Biomedical Engineering, Engineering (General), Life Sciences (General), Physics (General), Axon, tension release, Laser dissector, optical tweezers, force spectroscopy, neurons, neurites, cytoskeleton, adhesion, cell culture, microscopy
1Materials Science and Technology Division, Oak Ridge National Laboratory, 2Department of Physics & Astronomy, University of Tennessee, Knoxville
We describe the use of pulsed laser deposition (PLD), photolithography and wire-bonding techniques to create micrometer scale complex oxides devices. The PLD is utilized to grow epitaxial thin films. Photolithography and wire-bonding techniques are introduced to create practical devices for measurement purposes.
Published July 1, 2013. Keywords: Materials Science, Physics, Chemistry, Chemical Engineering, Mechanical Engineering, Nanotechnology, electrical transport properties in solids, condensed matter physics, thin films (theory, deposition and growth), conductivity (solid state), Pulsed laser deposition, oxides thin films, photolithography, wire-bonding, thin film, etching, fabrication, nanofabrication
1Department of Physics, University of California at Berkeley, 2Department of Chemistry, University of California at Berkeley, 3Department of Chemical and Biomolecular Engineering, University of California at Berkeley, 4National Institute for Materials Science (Japan), 5Materials Sciences Division, Lawrence Berkeley National Laboratory, 6Kavli Energy NanoSciences Institute, University of California at Berkeley and Lawrence Berkeley National Laboratory
This paper details the fabrication process of a gate-tunable graphene device, decorated with Coulomb impurities for scanning tunneling microscopy studies. Mapping the spatially dependent electronic structure of graphene in the presence of charged impurities unveils the unique behavior of its relativistic charge carriers in response to a local Coulomb potential.
Published July 24, 2015. Keywords: Engineering, Physics, graphene, electrostatic gating, scanning tunneling microscopy (STM), Coulomb impurity, chemical vapor deposition (CVD), poly(methyl methacrylate) (PMMA) transfer, wire bonding
1Department of Math and Sciences, Alvernia University, 2Applied Research Associates (ARA), Inc.
LIBS detection capabilities on soil simulants were tested using a range of pulse energies and timing parameters. Calibration curves were used to determine detection limits and sensitivities for different parameters. Generally, the results showed that there was not a significant reduction in detection capabilities using lower pulse energies and non-gated detection.
Published September 23, 2013. Keywords: Chemistry, analytical chemistry, laser research, atomic physics, [LIBS, Laser-induced breakdown spectroscopy, gated and non-gated detection, energy study]
1Department of Mechanical Engineering, Massachusetts Institute of Technology, 2Laboratory for Manufacturing and Productivity, Massachusetts Institute of Technology, 3School of Engineering and Applied Sciences, Harvard University, 4Department of Materials Science and Engineering, Massachusetts Institute of Technology, 5Department of Chemistry & Chemical Biology, Harvard University
Tin sulfide (SnS) is a candidate material for Earth-abundant, non-toxic solar cells. Here, we demonstrate the fabrication procedure of the SnS solar cells employing atomic layer deposition, which yields 4.36% certified power conversion efficiency, and thermal evaporation which yields 3.88%.
Published May 22, 2015. Keywords: Engineering, Solar cells, thin films, thermal evaporation, atomic layer deposition, annealing, tin sulfide
1Department of Medical Physics, Centre Oscar Lambret
A growing number of radiation therapy devices offer the advantage of delivering the dose through very small beams to the tumor, allowing for increased conformity and higher doses per fraction. Many different detectors can be used for the dosimetry of these small fields. In the present study, the effect of ion recombination is investigated for a liquid ionization chamber using a stereotactic radiation therapy system.…
Published May 9, 2014. Keywords: Physics, Radiation therapy, dosimetry, small fields, Cyberknife, liquid ionization, recombination effects
1Electrical Engineering and Computer Science Department, University of Michigan
We describe methods for the design, fabrication, and experimental characterization of plasmonic photoconductive emitters, which offer two orders of magnitude higher terahertz power levels compared to conventional photoconductive emitters.
Published July 8, 2013. Keywords: Physics, Electrical Engineering, Computer Science, Materials Science, Electronics and Electrical Engineering, Instrumentation and Photography, Lasers and Masers, Optics, Solid-State Physics, Terahertz, Plasmonic, Time-Domain Spectroscopy, Photoconductive Emitter, electronics
1Department of Agricultural and Biological Engineering, Mississippi State University, 2Center for Advanced Vehicular Systems, Mississippi State University
The current study prescribes a coupled experiment-finite element simulation methodology to obtain the uniaxial dynamic mechanical response of soft biomaterials (brain, liver, tendon, fat, etc.). The multiaxial experimental results that arose because of specimen bulging obtained from Split-Hopkinson Pressure Bar testing were rendered to a uniaxial true stress-strain behavior when simulated through iterative optimization of the finite element analysis of the biomaterial.…
Published May 18, 2015. Keywords: Bioengineering, Split-Hopkinson Pressure Bar, High Strain Rate, Finite Element Modeling, Soft Biomaterials, Dynamic Experiments, Internal State Variable Modeling, Brain, Liver, Tendon, Fat
1Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, 2Department of Chemistry, The Johns Hopkins University
We describe experimental details of the synthesis of patterned and reconfigurable particles from two dimensional (2D) precursors. This methodology can be used to create particles in a variety of shapes including polyhedra and grasping devices at length scales ranging from the micro to centimeter scale.
Published February 4, 2013. Keywords: Chemistry, Chemical Engineering, Biomolecular Engineering, Materials Science, Physics, Nanotechnology, Molecular Self-assembly, Electrochemistry, Folding, three dimensional, lithography, colloid, patchy particles, particles, nanoparticles, robotics, drug delivery, microfabrication, nanofabrication, nano, assembly, synthesis, reaction, origami
1Department of Physics, University of Illinois at Urbana-Champaign, 2Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, 3Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign
Single fluorophores can be localized with nanometer precision using FIONA. Here a summary of the FIONA technique is reported, and how to carry out FIONA experiments is described.
Published September 26, 2014. Keywords: Molecular Biology, FIONA, fluorescence imaging, nanometer precision, myosin walking, thick tissue
1Department of Electrical and Computer Engineering, The University of Utah, 2Department of Chemistry, The University of Wisconsin-Madison
We report that the diffraction limit of conventional optical lithography can be overcome by exploiting the transitions of organic photochromic derivatives induced by their photoisomerization at low light intensities.1-3 This paper outlines our fabrication technique and two locking mechanisms, namely: dissolution of one photoisomer and electrochemical oxidation.…
Published December 11, 2014. Keywords: Physics, Optics, nanomaterials, fabrication, nanolithography, optical nanolithography, sub-wavelength diffraction
1Geophysical Laboratory, Carnegie Institution of Washington
The high-pressure and high-temperature experiments described here mimic planet interior differentiation processes. The processes are visualized and better understood by high-resolution 3D imaging and quantitative chemical analysis.
Published November 15, 2013. Keywords: Physics, Geophysics, Planetary Science, Geochemistry, Planetary interior, high-pressure, planet differentiation, 3D tomography
1Fraunhofer Institute for Ceramic Technologies and Systems, 2Dresden Center for Nanoanalysis, Technische Universität Dresden, 3Globalfoundries Fab 8, 4Globalfoundries Fab 1
The time-dependent dielectric breakdown (TDDB) in on-chip interconnect stacks is one of the most critical failure mechanisms for microelectronic devices. This paper demonstrates the procedure of an in situ TDDB experiment in the transmission electron microscope, which opens a possibility to study the failure mechanism in microelectronic products.
Published June 26, 2015. Keywords: Engineering, Time-dependent dielectric breakdown, reliability, copper interconnect, degradation kinetics, in situ TEM, ultra-low-k (ULK) material
1Department of Mechanical Engineering, University of British Columbia
Two experimental devices for examining liquid jet impingement on a high-speed moving surface are described: an air cannon device and a spinning disk device. The apparatuses are used to determine optimal approaches to the application of liquid friction modifier (LFM) onto rail tracks for top-of-rail friction control.
Published April 17, 2015. Keywords: Engineering, Liquid jet impingement, high-speed moving surface, spray nozzle, liquid friction modifier (LFM), air cannon, spinning disk, rail track lubrication, fluid mechanics
1Department of Physics, University of California, San Diego, 2Department of Engineering Science and Mechanics, Pennsylvania State University, 3Department of Neurosurgery, Pennsylvania State University, 4Section of Neurobiology, University of California, San Diego
We present a method to form an imaging window in the mouse skull that spans millimeters and is stable for months without inflammation of the brain. This method is well suited for longitudinal studies of blood flow, cellular dynamics, and cell/vascular structure using two-photon microscopy.
Published March 7, 2012. Keywords: Neuroscience, cranial window, craniotomy, two-photon microscopy, blood flow, dendrite, optogenetics, cortex, capillary, microglia, chronic, mouse
1High Pressure Science and Engineering Center, Department of Physics and Astronomy, University of Nevada, Las Vegas, 2GeoSoilEnviroCARS, University of Chicago, 3High Pressure Collaborative Access Team, Carnegie Institution of Washington
The laser heated diamond anvil cell combined with synchrotron micro-diffraction techniques allows researchers to explore the nature and properties of new phases of matter at extreme pressure and temperature (PT) conditions. Heterogeneous samples can be characterized in situ under high pressure by 2D mapping and combined powder, single-crystal and multigrain diffraction approaches.…
Published October 7, 2013. Keywords: Physics, x-ray diffraction, geochemistry, geophysics, solid-state physics, high-pressure, high-temperature, Diamond anvil cell, micro-diffraction, novel materials, iron oxides, mantle mineralogy
1Department of Applied Physics, Eindhoven University of Technology, 2Dutch Institute for Fundamental Energy Research
We demonstrate how to determine the size distribution of semiconductor nanocrystals in a quantitative manner using Raman spectroscopy employing an analytically defined multi-particle phonon confinement model. Results obtained are in excellent agreement with the other size analysis techniques like transmission electron microscopy and photoluminescence spectroscopy.
Published August 22, 2015. Keywords: Engineering, Nanocrystal, size distribution, Raman spectroscopy, phonon confinement, size-dependent properties, silicon
1Institute of Shock Physics, Imperial College London
Fracture and fragmentation are late stage phenomena in dynamic loading scenarios and are typically studied using explosives. We present a technique for driving expansion using a gas gun which uniquely enables control of both loading rate and sample temperature.
Published June 28, 2015. Keywords: Engineering, Shock Physics, Fracture, Fragmentation, High Strain Rate, Expanding Cylinder, Ti-6Al-4V
1Center for Nanoscale Materials, Argonne National Laboratory, 2Institute for Molecular Engineering, University of Chicago
Organic photovoltaic (OPV) materials are inherently inhomogeneous at the nanometer scale. Nanoscale inhomogeneity of OPV materials affects performance of photovoltaic devices. In this paper, we describe a protocol for quantitative measurements of electrical and mechanical properties of OPV materials with sub-100 nm resolution.
Published January 23, 2013. Keywords: Materials Science, Nanotechnology, Mechanical Engineering, Electrical Engineering, Computer Science, Physics, electrical transport properties in solids, condensed matter physics, thin films (theory, deposition and growth), conductivity (solid state), AFM, atomic force microscopy, electrical properties, mechanical properties, organic photovoltaics, microengineering, photovoltaics
1Materials Science Division, Argonne National Laboratory, 2Energy Systems Division, Argonne National Laboratory, 3MassThink LLC
White light microscope interferometry is an optical, noncontact and quick method for measuring the topography of surfaces. It is shown how the method can be applied toward mechanical wear analysis, where wear scars on tribological test samples are analyzed; and in materials science to determine ion beam sputtering or laser ablation volumes and depths.
Published February 27, 2013. Keywords: Materials Science, Physics, Ion Beams (nuclear interactions), Light Reflection, Optical Properties, Semiconductor Materials, White Light Interferometry, Ion Sputtering, Laser Ablation, Femtosecond Lasers, Depth Profiling, Time-of-flight Mass Spectrometry, Tribology, Wear Analysis, Optical Profilometry, wear, friction, atomic force microscopy, AFM, scanning electron microscopy, SEM, imaging, visualization
1School of Physics & Astronomy, University of St Andrews
Use of photonic crystal slow light waveguides and cavities has been widely adopted by the photonics community in many differing applications. Therefore fabrication and characterization of these devices are of great interest. This paper outlines our fabrication technique and two optical characterization methods, namely: interferometric (waveguides) and resonant scattering (cavities).…
Published November 30, 2012. Keywords: Physics, Optics and Photonics, Astronomy, light scattering, light transmission, optical waveguides, photonics, photonic crystals, Slow-light, Cavities, Waveguides, Silicon, SOI, Fabrication, Characterization
1Department of Physics 0374, University of California, San Diego, 2Department of Psychiatry and Neuroscience, Centre de Recherche de l’Université Laval Robert-Giffard
This protocol describes the design and surgical implantation of a head-restraining mechanism to monitor neuronal activity in sub-cortical brain structures in alert rats. It delineates procedures to isolate single neurons in the juxtacellular configuration and to efficiently identify their anatomical locations.
Published April 27, 2015. Keywords: Neuroscience, electrophysiology, juxtacellular, iontophoresis, stereotaxic surgery, thalamus, vibrissa