A5071886371- Advanced Condensed Matter Physics
- Physics of Superconductivity and Magnetism
- Theoretical and Computational Physics
- Magnetic and transport properties of perovskites and related materials
- Nanofluid Flow and Heat Transfer
- Material Dynamics and Properties
- Microfluidic and Bio-sensing Technologies
- Planetary Science and Exploration
- Engineering Education and Pedagogy
- Engineering Education and Curriculum Development
- Spaceflight effects on biology
- Biocrusts and Microbial Ecology
- Experimental Learning in Engineering
- Pickering emulsions and particle stabilization
- Advanced Battery Technologies Research
- Microbial Inactivation Methods
- Advanced Battery Materials and Technologies
- Heat Transfer and Optimization
- Microfluidic and Capillary Electrophoresis Applications
- Thermal properties of materials
- Advancements in Battery Materials
- Inorganic Fluorides and Related Compounds
- Heat Transfer Mechanisms
- Slime Mold and Myxomycetes Research
- Microbial Community Ecology and Physiology
Draper Laboratory
2019-2022
California State University Los Angeles
2021
Franklin W. Olin College of Engineering
2009-2018
Montana Technological University
2012
Harvard University
2004-2007
Flinders University
2007
Ohio Business College
2005
Massachusetts Institute of Technology
1997-2003
Tohoku University
1997
Brookhaven National Laboratory
1997
This article reports on the International Nanofluid Property Benchmark Exercise, or INPBE, in which thermal conductivity of identical samples colloidally stable dispersions nanoparticles “nanofluids,” was measured by over 30 organizations worldwide, using a variety experimental approaches, including transient hot wire method, steady-state methods, and optical methods. The nanofluids tested exercise were comprised aqueous nonaqueous basefluids, metal oxide particles, near-spherical elongated...
Neutron scattering experiments have revealed a fascinating interplay between the hole doping, spin fluctuations, and superconductivity of cuprate superconductors. Recently, electrochemical techniques been used to produce large single crystals La 2 CuO 4+ y , which has mobile oxygen dopants. Staging behavior excess demonstrated, low-energy fluctuations in stage 6 measured. The are incommensurate with lattice spatial, energy, temperature dependencies very much like those 2− x Sr 4 similar high...
We study phase separation in a deeply quenched colloid-polymer mixture microgravity on the International Space Station using small-angle light scattering and direct imaging. observe clear crossover from early-stage spinodal decomposition to late-stage, interfacial-tension-driven coarsening. Data acquired over 5 orders of magnitude time show more than 3 increase domain size, following nearly same evolution as that binary liquid mixtures. The late-stage growth approaches expected linear rate...
Colloidal silica gels are shown to stiffen with time, as demonstrated by both dynamic light scattering and bulk rheological measurements. Their elastic moduli increase a power law independent of particle volume fraction; however, static indicates that there no large-scale structural changes. We propose increases in local elasticity arising from bonding between neighboring colloidal particles can account for the strengthening network, while preserving network structure.
We show that the dynamics of large fractal colloid aggregates are well described by a combination translational and rotational diffusion internal elastic fluctuations, allowing both aggregate size elasticity to be determined dynamic light scattering. The comparison results obtained in microgravity on Earth demonstrates cluster growth is limited gravity-induced restructuring. In absence gravity, thermal fluctuations ultimately inhibit set fundamental limitation lowest volume fraction which will gel.
The low-temperature magnetic excitations of the two-dimensional spin-5/2 square-lattice Heisenberg antiferromagnet Rb2MnF4 have been probed using pulsed inelastic neutron scattering. In addition to dominant sharp peaks identified with one-magnon excitations, a relatively weak continuum scattering is also observed at higher energies. This attributed by pairs magnons and intensities are consistent predictions spin wave theory.
Our novel device acoustophoretically transfers cells from culture media to electroporation and then electroporates them using integrated electrodes.
ABSTRACT Peer-mediated approaches have been used for years to improve the academic behaviors of students, especially those with disabilities. The most systematized and well researched peer-mediated relates peer tutoring systems, which include specific elements training, implementation, evaluation. purpose this article is distinguish systems from incidental approaches, document application within specialized areas (e.g., music or horticulture), show representative examplars data-based studies...
In the search for new, more effective coolant fluids, nanoparticle suspensions have shown promise due to their enhanced thermal conductivity. However, there is a concomitant increase in viscosity, requiring an pumping power achieve same flow rate. Studies of cooling simple geometries indicate that benefit using nanofluids, but it difficult justify extending these results far complicated geometries. Moreover, with variability property measurements found literature, possible show conflicting...
We report a neutron-scattering study of the dynamic spin correlations in ${\mathrm{Rb}}_{2}{\mathrm{MnF}}_{4},$ two-dimensional spin-5/2 antiferromagnet. By tuning an external magnetic field to value for spin-flop line, we reduce effective anisotropy essentially zero, thereby obtaining nearly ideal isotropic From shape quasielastic peak as function temperature, demonstrate scaling this system and find dynamical exponent z. compare these results theoretical predictions behavior Heisenberg...
Measurements are reported of the time dependence current during electrochemical oxidation and reduction at a fixed voltage single crystals ceramic samples ${\mathrm{La}}_{2}{\mathrm{CuO}}_{4+\mathrm{\ensuremath{\delta}}}.$ Staging peaks in neutron measurements together with magnetization confirm that stage $n=6$ corresponds to $\ensuremath{\delta}=0.055\ifmmode\pm\else\textpm\fi{}0.05,$ high-\ensuremath{\delta} side oxygen-rich--oxygen-poor miscibility gap. Furthermore, $n=4$ occurs value...
We examined biofilms formed by the metabolically versatile bacterium Rhodopseudomonas palustris grown via different metabolic modes. R. was in flow cell chambers with identical medium conditions either presence or absence of light and oxygen. In oxygen light, grew photoheterotrophically, heterotrophically. used confocal laser scanning microscopy image analysis software to quantitatively analyze compare biofilm formation over time these two describe quantifiable differences structure between...
Solid-state batteries offer the potential to improve safety, cyclability, and energy density of Li-ion batteries. However, their conductivity, stability, processing limit use. To this end, effects solid electrolyte microstructure on overall battery performance are determined. The conductivities Al-doped Li7La3Zr2O12 (Al-LLZO), with a range microstructures, found using resistor network model. Varying properties combined Li-metal negative electrode LiCoO2 positive in 1-D continuum model...
This work-in-progress, innovative-practice paper describes the creation and first two iterations of an experimental course which aims to develop a process-focused approach integrated quantitative engineering analysis in early stage students. The goal this two-semester is improve confidence competence our students choosing applying tools solve practical problems throughout their time college beyond, including other projects, senior capstone experiences, internships careers. led by...
We report a neutron scattering study of the spin correlations for spin- $5/2$ two-dimensional antiferromagnet $\mathrm{Rb}{}_{2}\mathrm{MnF}{}_{4}$ in an external magnetic field. Choosing fields near system's bicritical point, we tune effective anisotropy interaction to zero, constructing ideal $S\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}5/2$ Heisenberg system. The correlation length and structure factor amplitude are closely described by semiclassical theory Cuccoli et al. over...
Breakthrough cell therapies for the treatment of cancers require separation specific cells, such as T from patient's blood. Current therapy processes rely on magnetic separation, which adds clinical risk and requires elevated manufacturing controls due to added foreign material that constitutes beads. Acoustophoresis, a method uses ultrasound has demonstrated label-free enrichment cells blood, but residual other lymphocytes limit ultimate purity output product. Here, increase specificity...
The critical fluctuations of ${\mathrm{CuGeO}}_{3}$ have been measured by synchrotron x-ray scattering, and two length scales are clearly observed. ratio between the is found to be significantly different along a axis, with axis surface normal direction. We believe that such directional preference clear sign random strains, especially those caused dislocations, origin long scale fluctuations.
We report comprehensive synchrotron x-ray scattering and magnetic susceptibility studies of the doped spin–Peierls materials Cu 1- x Zn GeO 3 CuGe y Si O . Temperature versus dopant concentration phase diagrams are mapped out for both dopants. The closely resemble that Mg , including observation spin gap is established at a much higher temperature than which dimerization attains long-range order. transitions in samples exhibit unusual transition behavior, characterized by highly rounded...
A new, project-based-learning course, Quantitative Engineering Analysis, has been created and delivered at Olin College of that integrates introductory-level mathematics, physics, engineering. The course focuses on developing students' knowledge, skills, confidence in using quantitative analysis as part the engineering design process. structure is built around multidisciplinary projects; one which involves a boat draws fundamentals marine naval architecture to teach core concepts such vector...
In response to the well documented lack of highly qualified STEM educators in United States, this work seeks understand how increase interest K-12 teaching among engineering students. This paper presents a preliminary framework and findings exploring factors that motivate choice career alumni small college. particular, it focuses on relationship between ways which study participants defined "teaching" "teacher" their post-graduate interests pursuits. Fourteen subjects participated...
We present results of a systematic x-ray scattering study the effects Mg doping on high-field incommensurate phase ${\mathrm{CuGeO}}_{3}.$ Lorentzian-squared line shapes, changing first-order transition to second order, and destruction long-range order with infinitesimal are observed, consistent random-field in three-dimensional $\mathrm{XY}$ system. Values for soliton width pure lightly doped ${\mathrm{CuGeO}}_{3}$ deduced. find that even very small has drastic effect shape lattice modulation.
Biofilms are how bacteria naturally exist‐enclosed in an extracellular matrix of proteins, nucleic acids, and polysaccharides. This state protects against environmental stresses, such as antibiotics biocides. Two strains Synechocystis sp. Strain 6803, a wildtype strain extremely motile mutant strain, were grown flow cells under identical conditions their biofilms analyzed using confocal microscopy. A significant difference was found terms biofilm structures growth. Wildtype significantly...