A5037565169- Thermal properties of materials
- Photonic and Optical Devices
- Photonic Crystals and Applications
- Gas Sensing Nanomaterials and Sensors
- Aerogels and thermal insulation
- Optical Coatings and Gratings
- Analytical Chemistry and Sensors
- Advanced Sensor and Energy Harvesting Materials
- Building Energy and Comfort Optimization
- Advanced Chemical Sensor Technologies
- Electrochemical sensors and biosensors
- Metal and Thin Film Mechanics
- High voltage insulation and dielectric phenomena
- Heat and Mass Transfer in Porous Media
- Scientific Measurement and Uncertainty Evaluation
- Calibration and Measurement Techniques
- Natural Fiber Reinforced Composites
- Hybrid Renewable Energy Systems
- Plant Molecular Biology Research
- Advanced Nanomaterials in Catalysis
- Polymer Foaming and Composites
- Thermal Radiation and Cooling Technologies
- Dielectric materials and actuators
- Force Microscopy Techniques and Applications
- Advanced Sensor Technologies Research
University of Dayton
2021-2024
Oak Ridge National Laboratory
2020-2021
National Transportation Research Center
2021
Louisiana Tech University
2017-2019
University of Lucknow
2009-2012
Manipulating thermal conductivity through nanoengineering is of critical importance to advance technologies, such as soft robotics, artificial skin, wearable electronics, batteries, insulation, and thermoelectrics. Here, by examining amorphous polymers, including polystyrene, polypropylene, polyethylene, ethylene vinyl alcohol, using molecular dynamics simulations, we find that the conductivities polymers can be reduced below their limit size effects. Size-dependent transport in materials...
Diabetic individuals need simple, accurate, and cost effective means by which to independently assess their glucose levels in a non-invasive way. In this work, sensor based on randomly oriented CuO nanowire networks supported polyethylene terephthalate thin film is evaluated as flexible, transparent, non-enzymatic sensing system analogous those envisioned for future wearable diagnostic devices. The amperometric characteristics of type device architecture are both before after bending, with...
In this paper we report humidity sensing studies of undoped and SnO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> doped WO xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> . Sensitivity is 13.48 MΩ/%RH for -SnO nanocomposite. Hysteresis less than 3% Aging nanocomposite 5.7%. Activation energy conduction obtained from Arrhenius graph are 0.127 eV in 27°C to 200°C 0.547 600°C temperature range Response time recovery sample 117 s 411...
The ability of graphene to serve as an ultrathin heat spreader has been previously demonstrated with impressive results. However, is electrically conductive, making its use in contact electronic devices problematic from a reliability and integration perspective. As alternative, hexagonal boron nitride (h-BN) similarly structured material large in-plane thermal conductivity but which possesses wide band gap, thereby giving it potential be utilized for directing contact, near-junction...
The development of insulation materials with low effective thermal conductivity is essential for energy savings in various applications, including buildings, food services, pipe insulation, and refrigeration. Such can be developed by using micro- or nanoporous structures, as well low-thermal gases and/or reduced pressure. A variety medium approximation (EMA) models have been to study transport through solid porous structures. However, many cases, the impacts porosity on conduction are not...
Spatially Variant Photonic Crystals (SVPCs) have shown the ability to control propagation and direction of light in near-infrared spectrum. Using a novel approach for simplified modeling fabrication techniques, we designed unique, spatially-varied, unit-cell structures develop photonic crystals that maintain self-collimation desired beam tuning applications. The finite-difference time-domain technique is used predict beam-bending capabilities our SVPCs. These SVPC designs simulation results...
In this paper we report application of Cu2O doped ZnO composite prepared by solid state reaction route as humidity sensor. Pellet samples ZnO‐Cu2O nanocrystalline powders with 2, 5 and 10 weight% in have been prepared. Pellets annealed at temperatures 200–500° C exposed to humidity. It is observed that relative increases, resistance the pellet decreases for from 10% 90%. Sample 5% 500° shows best results sensitivity 1.50 MΩ/%RH. case hysteresis low reproducibility high, making it suitable...
This work explores the design, fabrication, and testing of spatially variant photonic crystals to achieve beam control in near-infrared spectrum. These capabilities can improve optical systems for increased transmission direction light.
Abstract The self-collimation of light through Photonic Crystals (PCs) due to their optical properties and a special geometric structure offers new form beam steering with highly control capabilities for range different applications. objective this work is understand bending beams bio-inspired Spatially Variant (SVPCs) made from dielectric materials such as silicon dioxide common polymers used in three-dimensional printing like SU-8. Based upon natural PCs found animals butterflies fish, the...
Paper reports sensing studies of NO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> gas by WO xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> (prepared through sol-gel route) and Ag doped for operating temperatures 200°C, 250°C 300°C, concentration 0 to 100 ppm. Both pure show better sensitivity the temperature 200°C. both increase in value with increasing (ppm) . For ppm, element over increased 25% Response time sensors depend on...
We propose several means to improve the current gas and solid thermal conductivity models for insulation materials. With refined models, we decompose effective into gas, solid, radiation contributions expanded polystyrene (EPS), high-density EPS (HD-EPS), polyurethane (PUR) foams, PUR aerogels, silica vacuum panel (VIP) cores, fumed boards with various gases pressures. For cellular foams (EPS, HD-EPS, foams), relative air are 58%, 75%, 72%, 3%, 9%, 11%, 38%, 16%, 17%, respectively. granular...