Open Access. Powered by Scholars. Published by Universities.®
Nanoscience and Nanotechnology Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Electrical and Computer Engineering (34)
- Electrical and Electronics (19)
- Chemical Engineering (16)
- Physical Sciences and Mathematics (13)
- Electronic Devices and Semiconductor Manufacturing (10)
-
- Materials Science and Engineering (9)
- Catalysis and Reaction Engineering (7)
- Mechanical Engineering (7)
- Physics (7)
- Process Control and Systems (7)
- Civil and Environmental Engineering (6)
- Environmental Engineering (6)
- Life Sciences (6)
- Operations Research, Systems Engineering and Industrial Engineering (5)
- Social and Behavioral Sciences (5)
- Library and Information Science (4)
- Applied Mathematics (3)
- Applied Mechanics (3)
- Bioinformatics (3)
- Business (3)
- Chemistry (3)
- Computer Engineering (3)
- Computer Sciences (3)
- Computer and Systems Architecture (3)
- E-Commerce (3)
- Electromagnetics and Photonics (3)
- Fluid Dynamics (3)
- Management Information Systems (3)
- Institution
- Keyword
-
- Nanotechnology (18)
- Carbon nanotubes (11)
- Nanoparticles (11)
- Electrophoresis (10)
- Elemental semiconductors (7)
-
- Adhesion (5)
- Encapsulation (5)
- Polymers (5)
- Brittleness (4)
- Finite element analysis (4)
- Gold (4)
- Hardness (4)
- Scanning electron microscopy (4)
- Silicon (4)
- Toxicology (4)
- Caco-2 cells (3)
- Department of Agricultural and Biological Engineering (3)
- Dip coating (3)
- Elasticity (3)
- Electrical resistivity (3)
- Ingestion (3)
- Nanomaterial exposure (3)
- Nanostructures (3)
- Nanotube devices (3)
- Nanotubes (3)
- Polymer films (3)
- Self-assembly (3)
- Semiconductor nanotubes (3)
- Tensile testing (3)
- Viscosity (3)
- Publication
-
- Ahmed A. Busnaina (9)
- Mehmet R. Dokmeci (9)
- João F Gomes (6)
- Nicol E. McGruer (4)
- Yung Joon Jung (4)
-
- Anja V. Mudring (3)
- Dr Deogratias Harorimana (3)
- George G. Adams (3)
- Jonathan C. Claussen (3)
- Mikhail Khenner (3)
- Dattatri K. Nagesha (2)
- Latika Menon (2)
- Wenyu Huang (2)
- Albert B Chen (1)
- Allan Widom (1)
- Carmine Vittoria (1)
- Eng-Poh Ng (1)
- Ganesh Balasubramanian (1)
- Jen Schneider (1)
- Kai-tak Wan (1)
- Katherine S. Ziemer (1)
- Kok Hoong Leong (1)
- Li Tang (1)
- Rebecca L. Carrier (1)
- Scott L Whittenburg (1)
- Shumin Li (1)
- Shweta Chopra (1)
- Sinan Müftü (1)
- Srinivas Sridhar (1)
- Tianxiang Nan (1)
- File Type
Articles 31 - 60 of 70
Full-Text Articles in Nanoscience and Nanotechnology
Separation Modes In Microcontacts Identified By The Rate Dependence Of The Pull-Off Force, L. Chen, Nicol E. Mcgruer, George G. Adams, Yan Du
Separation Modes In Microcontacts Identified By The Rate Dependence Of The Pull-Off Force, L. Chen, Nicol E. Mcgruer, George G. Adams, Yan Du
George G. Adams
We report the observation of two distinct modes of rate-dependent behavior during contact cycling tests. One is a higher pull-off force at low cycling rates and the other is a higher pull-off force at high cycling rates. Subsequent investigation of these contacts using scanning electron microscopy (SEM) demonstrates that these two rate-dependent modes can be related to brittle and ductile separation modes. The former behavior is indicative of brittle separation, whereas the latter accompanies ductile separation. Thus by monitoring the rate dependence of the pull-off force, the type of separation mode can be identified during cycling without interrupting the test …
Contact Resistance Study Of Noble Metals And Alloy Films Using A Scanning Probe Microscope Test Station, Lei Chen, H. Lee, Z. J. Guo, Nicol E. Mcgruer, K. W. Gilbert, S. Mall, Kevin D. Leedy, George G. Adams
Contact Resistance Study Of Noble Metals And Alloy Films Using A Scanning Probe Microscope Test Station, Lei Chen, H. Lee, Z. J. Guo, Nicol E. Mcgruer, K. W. Gilbert, S. Mall, Kevin D. Leedy, George G. Adams
George G. Adams
The proper selection of electrical contact materials is one of the critical steps in designing a metal contact microelectromechanical system (MEMS) switch. Ideally, the contact should have both very low contact resistance and high wear resistance. Unfortunately this combination cannot be easily achieved with the contact materials currently used in macroswitches because the available contact force in microswitches is generally insufficient (less than 1 mN) to break through nonconductive surface layers. As a step in the materials selection process, three noble metals, platinum (Pt), rhodium (Rh), ruthenium (Ru), and their alloys with gold (Au) were deposited as thin films on …
A Parameter Study Of Separation Modes Of Adhering Microcontacts, Yan Du, George G. Adams, Nicol E. Mcgruer, Izhak Etsion
A Parameter Study Of Separation Modes Of Adhering Microcontacts, Yan Du, George G. Adams, Nicol E. Mcgruer, Izhak Etsion
George G. Adams
A finite element model was developed to study adhesion of elastic-plastic microcontacts in a previous investigation. An interesting result was the identification of two distinct separation modes, i.e. brittle and ductile separation. In the current study, that model is used to conduct a series of simulations to determine the influence of four nondimensional parameters (including the maximum load parameter) on the contact and on the separation modes. The results show that the parameter S (the ratio of the theoretical stress to the hardness) and δƒ/δc (representing the loading level) are the most important. Smaller S can only lead to brittle …
Separation Modes In Microcontacts Identified By The Rate Dependence Of The Pull-Off Force, L. Chen, Nicol Mcgruer, George Adams, Yan Du
Separation Modes In Microcontacts Identified By The Rate Dependence Of The Pull-Off Force, L. Chen, Nicol Mcgruer, George Adams, Yan Du
Nicol E. McGruer
We report the observation of two distinct modes of rate-dependent behavior during contact cycling tests. One is a higher pull-off force at low cycling rates and the other is a higher pull-off force at high cycling rates. Subsequent investigation of these contacts using scanning electron microscopy (SEM) demonstrates that these two rate-dependent modes can be related to brittle and ductile separation modes. The former behavior is indicative of brittle separation, whereas the latter accompanies ductile separation. Thus by monitoring the rate dependence of the pull-off force, the type of separation mode can be identified during cycling without interrupting the test …
Contact Resistance Study Of Noble Metals And Alloy Films Using A Scanning Probe Microscope Test Station, Lei Chen, H. Lee, Z. J. Guo, Nicol E. Mcgruer, K. W. Gilbert, S. Mall, Kevin D. Leedy, George G. Adams
Contact Resistance Study Of Noble Metals And Alloy Films Using A Scanning Probe Microscope Test Station, Lei Chen, H. Lee, Z. J. Guo, Nicol E. Mcgruer, K. W. Gilbert, S. Mall, Kevin D. Leedy, George G. Adams
Nicol E. McGruer
The proper selection of electrical contact materials is one of the critical steps in designing a metal contact microelectromechanical system (MEMS) switch. Ideally, the contact should have both very low contact resistance and high wear resistance. Unfortunately this combination cannot be easily achieved with the contact materials currently used in macroswitches because the available contact force in microswitches is generally insufficient (less than 1 mN) to break through nonconductive surface layers. As a step in the materials selection process, three noble metals, platinum (Pt), rhodium (Rh), ruthenium (Ru), and their alloys with gold (Au) were deposited as thin films on …
A Parameter Study Of Separation Modes Of Adhering Microcontacts, Yan Du, George G. Adams, Nicol E. Mcgruer, Izhak Etsion
A Parameter Study Of Separation Modes Of Adhering Microcontacts, Yan Du, George G. Adams, Nicol E. Mcgruer, Izhak Etsion
Nicol E. McGruer
A finite element model was developed to study adhesion of elastic-plastic microcontacts in a previous investigation. An interesting result was the identification of two distinct separation modes, i.e. brittle and ductile separation. In the current study, that model is used to conduct a series of simulations to determine the influence of four nondimensional parameters (including the maximum load parameter) on the contact and on the separation modes. The results show that the parameter S (the ratio of the theoretical stress to the hardness) and δƒ/δc (representing the loading level) are the most important. Smaller S can only lead to brittle …
Scalable Nanotemplate Assisted Directed Assembly Of Single Walled Carbon Nanotubes For Nanoscale Devices, Prashanth Makaram, Sivasubramanian Somu, Xugang Xiong, Ahmed A. Busnaina, Yung-Joon Jung, Nicol E. Mcgruer
Scalable Nanotemplate Assisted Directed Assembly Of Single Walled Carbon Nanotubes For Nanoscale Devices, Prashanth Makaram, Sivasubramanian Somu, Xugang Xiong, Ahmed A. Busnaina, Yung-Joon Jung, Nicol E. Mcgruer
Nicol E. McGruer
The authors demonstrate precise alignment and controlled assembly of single wall nanotube (SWNT) bundles at a fast rate over large areas by combining electrophoresis and dip coating processes. SWNTs in solution are assembled on prepatterned features that are 80 nm wide and separated by 200 nm. The results show that the direction of substrate withdrawal significantly affects the orientation and alignment of the assembled SWNT bundles. I-V characterization is carried out to demonstrate electrical continuity of these assembled SWNT bundles.
Mechanical And Electrical Evaluation Of Parylene-C Encapsulated Carbon Nanotube Networks On A Flexible Substrate, Chia-Ling Chen, Ernesto Lopez, Yung-Joon Jung, Sinan Müftü, Selvapraba Selvarasah, Mehmet R. Dokmeci
Mechanical And Electrical Evaluation Of Parylene-C Encapsulated Carbon Nanotube Networks On A Flexible Substrate, Chia-Ling Chen, Ernesto Lopez, Yung-Joon Jung, Sinan Müftü, Selvapraba Selvarasah, Mehmet R. Dokmeci
Yung Joon Jung
Carbon nanotube networks are an emerging conductive nanomaterial with applications including thin film transistors, interconnects, and sensors. In this letter, we demonstrate the fabrication of single-walled carbon nanotube (SWNT) networks on a flexible polymer substrate and then provide encapsulation utilizing a thin parylene-C layer. The encapsulated SWNT network was subjected to tensile tests while its electrical resistance was monitored. Tests showed a linear-elastic response up to a strain value of 2.8% and nearly linear change in electrical resistance in the 0%–2% strain range. The networks’ electrical resistance was monitored during load-unload tests of up to 100 cycles and was hysteresis-free.
Parallel Arrays Of Individually Addressable Single-Walled Carbon Nanotube Field-Effect Transistors, Sarah Lastella, Govind Mallick, Raymond Woo, Shashi Karna, David Rider, Ian Manners, Yung-Joon Jung, Chang Ryu, Pulickel Ajayan
Parallel Arrays Of Individually Addressable Single-Walled Carbon Nanotube Field-Effect Transistors, Sarah Lastella, Govind Mallick, Raymond Woo, Shashi Karna, David Rider, Ian Manners, Yung-Joon Jung, Chang Ryu, Pulickel Ajayan
Yung Joon Jung
High-throughput field-effect transistors (FETs) containing over 300 disentangled, high-purity chemical-vapor-deposition-grown single-walled carbon nanotube (SWNT) channels have been fabricated in a three-step process that creates more than 160 individually addressable devices on a single silicon chip. This scheme gives a 96% device yield with output currents averaging 5.4 mA and reaching up to 17 mA at a 300 mV bias. Entirely semiconducting FETs are easily realized by a high current selective destruction of metallic tubes. The excellent dispersity and nearly-defect-free quality of the SWNT channels make these devices also useful for nanoscale chemical and biological sensor applications.
Scalable Nanotemplate Assisted Directed Assembly Of Single Walled Carbon Nanotubes For Nanoscale Devices, Prashanth Makaram, Sivasubramanian Somu, Xugang Xiong, Ahmed A. Busnaina, Yung-Joon Jung, Nicol E. Mcgruer
Scalable Nanotemplate Assisted Directed Assembly Of Single Walled Carbon Nanotubes For Nanoscale Devices, Prashanth Makaram, Sivasubramanian Somu, Xugang Xiong, Ahmed A. Busnaina, Yung-Joon Jung, Nicol E. Mcgruer
Yung Joon Jung
The authors demonstrate precise alignment and controlled assembly of single wall nanotube (SWNT) bundles at a fast rate over large areas by combining electrophoresis and dip coating processes. SWNTs in solution are assembled on prepatterned features that are 80 nm wide and separated by 200 nm. The results show that the direction of substrate withdrawal significantly affects the orientation and alignment of the assembled SWNT bundles. I-V characterization is carried out to demonstrate electrical continuity of these assembled SWNT bundles.
Mechanical And Electrical Evaluation Of Parylene-C Encapsulated Carbon Nanotube Networks On A Flexible Substrate, Chia-Ling Chen, Ernesto Lopez, Yung-Joon Jung, Sinan Müftü, Selvapraba Selvarasah, Mehmet R. Dokmeci
Mechanical And Electrical Evaluation Of Parylene-C Encapsulated Carbon Nanotube Networks On A Flexible Substrate, Chia-Ling Chen, Ernesto Lopez, Yung-Joon Jung, Sinan Müftü, Selvapraba Selvarasah, Mehmet R. Dokmeci
Mehmet R. Dokmeci
Carbon nanotube networks are an emerging conductive nanomaterial with applications including thin film transistors, interconnects, and sensors. In this letter, we demonstrate the fabrication of single-walled carbon nanotube (SWNT) networks on a flexible polymer substrate and then provide encapsulation utilizing a thin parylene-C layer. The encapsulated SWNT network was subjected to tensile tests while its electrical resistance was monitored. Tests showed a linear-elastic response up to a strain value of 2.8% and nearly linear change in electrical resistance in the 0%–2% strain range. The networks’ electrical resistance was monitored during load-unload tests of up to 100 cycles and was hysteresis-free.
Directed Assembly Of Gold Nanoparticle Nanowires And Networks For Nanodevices, Xugang Xiong, Ahmed A. Busnaina, Selvapraba Selvarasah, Sivasubramanian Somu, Ming Wei, Joey Mead, Chia-Ling Chen, Juan Aceros, Prashanth Makaram, Mehmet R. Dokmeci
Directed Assembly Of Gold Nanoparticle Nanowires And Networks For Nanodevices, Xugang Xiong, Ahmed A. Busnaina, Selvapraba Selvarasah, Sivasubramanian Somu, Ming Wei, Joey Mead, Chia-Ling Chen, Juan Aceros, Prashanth Makaram, Mehmet R. Dokmeci
Mehmet R. Dokmeci
Alternating electric field is used to assemble gold nanoparticle nanowires from liquid suspensions. The effects of electrode geometry and the dielectrophoresis force on the chaining and branching of nanowire formation are investigated. The nanowire assembly processes are modeled using finite element calculations, and the particle trajectories under the combined influence of dielectrophoresis force and viscous drag are simulated. Nanoparticle nanowires with 10 nm resolution are fabricated. The wires can be further oriented along an externally introduced flow. This work provides an approach towards rapid assembly and organization of ultrasmall nanoparticle networks.
Toxicity Of Cdse Nanoparticles In Caco-2 Cell Cultures, Lin Wang, Dattatri Nagesha, Selvapraba Selvarasah, Mehmet Dokmeci, Rebecca Carrier
Toxicity Of Cdse Nanoparticles In Caco-2 Cell Cultures, Lin Wang, Dattatri Nagesha, Selvapraba Selvarasah, Mehmet Dokmeci, Rebecca Carrier
Mehmet R. Dokmeci
Background
Potential routes of nanomaterial exposure include inhalation, dermal contact, and ingestion. Toxicology of inhalation of ultra-fine particles has been extensively studied; however, risks of nanomaterial exposure via ingestion are currently almost unknown. Using enterocyte-like Caco-2 cells as a small intestine epithelial model, the possible toxicity of CdSe quantum dot (QD) exposure via ingestion was investigated. Effect of simulated gastric fluid treatment on CdSe QD cytotoxicity was also studied.
Results
Commercially available CdSe QDs, which have a ZnS shell and poly-ethylene glycol (PEG) coating, and in-house prepared surfactant coated CdSe QDs were dosed to Caco-2 cells. Cell viability and attachment …
Nanoengineering Of A Negative-Index Binary-Staircase Lens For The Optics Regime, Bernard Didier F. Casse, Ravinder K. Banyal, W. T. Lu, Y. J. Huang, Selvapraba Selvarasah, Mehmet R. Dokmeci, Srinivas Sridhar
Nanoengineering Of A Negative-Index Binary-Staircase Lens For The Optics Regime, Bernard Didier F. Casse, Ravinder K. Banyal, W. T. Lu, Y. J. Huang, Selvapraba Selvarasah, Mehmet R. Dokmeci, Srinivas Sridhar
Mehmet R. Dokmeci
We show that a binary-staircase optical element can be engineered to exhibit an effective negative index of refraction, thereby expanding the range of optical properties theoretically available for future optoelectronic devices. The mechanism for achieving a negative-index lens is based on exploiting the periodicity of the surface corrugation. By designing and nanofabricating a planoconcave binary-staircase lens in the InP/InGaAsP platform, we have experimentally demonstrated at 1.55 μm that such negative-index concave lenses can focus plane waves. The beam propagation in the lens was studied experimentally and was in excellent agreement with the three-dimensional finite-difference time-domain numerical simulations.
Three Dimensional Controlled Assembly Of Gold Nanoparticles Using A Micromachined Platform, Nishant Khanduja, Selvapraba Selvarasah, Chia-Ling Chen, Mehmet R. Dokmeci, Xugang Xiong, Prashanth Makaram, Ahmed A. Busnaina
Three Dimensional Controlled Assembly Of Gold Nanoparticles Using A Micromachined Platform, Nishant Khanduja, Selvapraba Selvarasah, Chia-Ling Chen, Mehmet R. Dokmeci, Xugang Xiong, Prashanth Makaram, Ahmed A. Busnaina
Mehmet R. Dokmeci
By using optical lithographic procedures, the authors present a micromachined platform for large scale three dimensional (3D) assembly of gold nanoparticles with diameters of ∼ 50 nm. The gold nanoparticles are formed into 3D low resistance bridges (two terminal resistance of ∼ 40 Ω) interconnecting the two microelectrodes using ac dielectrophoresis. The thickness of the parylene interlevel dielectric can be adjusted to vary the height of the 3D platform for meeting different application requirements. This research represents a step towards realizing high density, three dimensional structures and devices for applications such as nanosensors, vertical integration of nanosystems, and characterization of …
Nanoengineering Of A Negative-Index Binary-Staircase Lens For The Optics Regime, Bernard Didier Casse, Ravinder Banyal, W. Lu, Y. Huang, Selvapraba Selvarasah, Mehmet Dokmeci, Srinivas Sridhar
Nanoengineering Of A Negative-Index Binary-Staircase Lens For The Optics Regime, Bernard Didier Casse, Ravinder Banyal, W. Lu, Y. Huang, Selvapraba Selvarasah, Mehmet Dokmeci, Srinivas Sridhar
Srinivas Sridhar
We show that a binary-staircase optical element can be engineered to exhibit an effective negative index of refraction, thereby expanding the range of optical properties theoretically available for future optoelectronic devices. The mechanism for achieving a negative-index lens is based on exploiting the periodicity of the surface corrugation. By designing and nanofabricating a planoconcave binary-staircase lens in the InP/InGaAsP platform, we have experimentally demonstrated at 1.55 μm that such negative-index concave lenses can focus plane waves. The beam propagation in the lens was studied experimentally and was in excellent agreement with the three-dimensional finite-difference time-domain numerical simulations.
Microwave Absorption Of Patterned Arrays Of Nanosized Magnetic Stripes With Different Aspect Ratios, Leszek M. Malkinski, Minghui Yu, Andriy Y. Voyk, Donald J. Scherer Ii, Leonard Spinu, Weillie Zhou, Scott Whittenburg, Zachary Davis, Jin-Seung Jung
Microwave Absorption Of Patterned Arrays Of Nanosized Magnetic Stripes With Different Aspect Ratios, Leszek M. Malkinski, Minghui Yu, Andriy Y. Voyk, Donald J. Scherer Ii, Leonard Spinu, Weillie Zhou, Scott Whittenburg, Zachary Davis, Jin-Seung Jung
Scott L Whittenburg
Arrays consisting of nanosized stripes of Permalloy with different length-to-width ratios have been fabricated using electron beam nanolithography, magnetron sputtering, and lift-off process. These stripes have a thickness of 100 nm, a width of 300 nm, and different lengths ranging from 300 nm to 100 μm. The stripes are separated by a distance of 1 μm. Magnetization hysteresis loops were measured using a superconducting quantum interference device susceptometer. Microwave absorption at 9.8 GHz was determined by means of ferromagnetic resonance technique. The dependence of the resonant field on the angle between the nanostructure and the in-plane dc magnetic field indicates …
Effect Of Thermal Stabilizers Composed Of Zinc Barbiturate And Calcium Stearate For Rigid Poly(Vinyl Chloride).Pdf, Shumin Li
Shumin Li
Carboxymethylation Of Kappa-Carrageenan For Intestinal-Targeted Delivery Of Bioactive Macromolecules, Kok Hoong Leong
Carboxymethylation Of Kappa-Carrageenan For Intestinal-Targeted Delivery Of Bioactive Macromolecules, Kok Hoong Leong
Kok Hoong Leong
The work presented herein discusses the carboxymethylation of kappa-carrageenan, a natural linear polysaccharide, to afford a pH-dependent swelling property allowing for intestinal-targeted delivery of bioactive macromolecules. The carboxymethylation conditions with respect to the volume and concentration of sodium hydroxide (VNaOH, CNaOH), weight of monochloroacetic acid (WMCA), and reaction temperature (T) were optimized using a response surface method incorporating a multivariate spline interpolation technique (RSMS). Fluorescein isothiocyanate-labeled dextran (FD-4; 4.4 kDa) was used as a hydrophilic macromolecule model. Beads made from encapsulating FD-4 in the carboxymethylated kappa-carrageenan displayed pH-dependent swelling and encapsulation efficiency of 74%. The release of FD-4 was low …
Synthesis Of Ordered Arrays Of Multiferroic Nife₂O₄-Pb(Zr₀.₅₂Ti₀.₄₈)O₃ Core-Shell Nanowires, Ming Liu, Xin Li, Hassan Imrane, Yajie Chen, Trevor L. Goodrich, Zhuhua Cai, Katherine S. Ziemer, Jian Y. Huang, Nian X. Sun
Synthesis Of Ordered Arrays Of Multiferroic Nife₂O₄-Pb(Zr₀.₅₂Ti₀.₄₈)O₃ Core-Shell Nanowires, Ming Liu, Xin Li, Hassan Imrane, Yajie Chen, Trevor L. Goodrich, Zhuhua Cai, Katherine S. Ziemer, Jian Y. Huang, Nian X. Sun
Katherine S. Ziemer
A synthesis method was developed for producing core-shell nanowire arrays, which involved a combination of a modified sol-gel process, electrochemical deposition, and subsequent oxidization in anodized nanoporous alumina membranes. This method was applied to generate ordered arrays of one dimensional multiferroic NiFe₂O₄ core and Pb(Zr₀.₅₂Ti₀.₄₈)O₃ (PZT) shell nanostructures. Extensive microstructural, magnetic, and ferroelectric characterizations confirmed that the regular arrays of core-shell multiferroic nanostructures were composed of a spinel NiFe₂O₄ core and perovskite PZT shell. This synthesis method can be readily extended to prepare different core-shell nanowire arrays and is expected to pave the way for one dimensional core-shell nanowire arrays.
Study On The Glycerolysis Reaction Of High Free Fatty Acid Oils For Use As Biodiesel Feedstock, João F. Gomes
Study On The Glycerolysis Reaction Of High Free Fatty Acid Oils For Use As Biodiesel Feedstock, João F. Gomes
João F Gomes
Biodiesel is the main alternative to fossil diesel and it may be produced from different feedstocks such as semi-refined vegetable oils, waste frying oils or animal fats. However, these feedstocks usually contain significant amounts of free fatty acids (FFA) that make them inadequate for the direct base catalyzed transesterification reaction (where the FFA content should be lower than 4%). The present work describes a possible method for the pre-treatment of oils with high content of FFA (20 to 50%) by esterification with glycerol. In order to reduce the FFA content, the reaction between these FFA and an esterification agent is …
Design Of A New Test Chamber For Evaluation Of The Toxicity Of Rubber Infill, João F. Gomes
Design Of A New Test Chamber For Evaluation Of The Toxicity Of Rubber Infill, João F. Gomes
João F Gomes
A test chamber was projected and built (according to ISO 16000-9 Standard) to simulate atmospheric conditions experienced by rubber infill (when applied in synthetic turf pitches) and measure accurately the airborne emissions of pollutants such as dusts and volatile organic compounds (VOC), as well as pollutants present in leacheates. It should be pointed out that standard ISO 16000-9 is only concerned with the determination of the emission of VOC from building products and furnishing (not specific of synthetic turf materials), while other standards are concerned with the emission of leacheates only. This procedure is to be considered as a technical …
What Is A Chemical Engineer ?, João F. Gomes
On The Toxicological Effects Of Airborne Nanoparticles From Welding Processes, João F. Gomes
On The Toxicological Effects Of Airborne Nanoparticles From Welding Processes, João F. Gomes
João F Gomes
No abstract provided.
Nanosized Molecular Sieves Utilized As An Environmentally Friendly Alternative To Antioxidants For Lubricant Oils, Eng-Poh Ng Dr.
Nanosized Molecular Sieves Utilized As An Environmentally Friendly Alternative To Antioxidants For Lubricant Oils, Eng-Poh Ng Dr.
Eng-Poh Ng
Lubricants play a significant part in current environmental considerations since they are an integral and indispensable component of modern technology. The production, application and disposal of the lubricants have to follow increasingly strict requirements for protecting the environment and living organisms. In this respect, molecular sieve (LTL type zeolite) is investigated as a potential environmentally friendly alternative to traditional antioxidant additives for lubricant oils. Accelerated oxidation experiments using pure base oil and additivated base oil in the presence of the LTL molecular sieve are carried out in parallel, and the oxidation processes are monitored by FT-IR spectroscopy, spectrophotometry, chromatography, total …
Microbiosensors Based On Dna Modified Single-Walled Carbon Nanotube And Pt Black Nanocomposites, Jin Shi, Tae-Gon Cha, Jonathan C. Claussen, Alfred R. Diggs, Jong Hyun Choi, D. Marshall Porterfield
Microbiosensors Based On Dna Modified Single-Walled Carbon Nanotube And Pt Black Nanocomposites, Jin Shi, Tae-Gon Cha, Jonathan C. Claussen, Alfred R. Diggs, Jong Hyun Choi, D. Marshall Porterfield
Jonathan C. Claussen
Glucose and ATP biosensors have important applications in diagnostics and research. Biosensors based on conventional materials suffer from low sensitivity and low spatial resolution. Our previous work has shown that combining single-walled carbon nanotubes (SWCNTs) with Pt nanoparticles can significantly enhance the performance of electrochemical biosensors. The immobilization of SWCNTs on biosensors remains challenging due to the aqueous insolubility originating from van der Waals forces. In this study, we used single-stranded DNA (ssDNA) to modify SWCNTs to increase solubility in water. This allowed us to explore new schemes of combining ssDNA-SWCNT and Pt black in aqueous media systems. The result …
Electrochemical Glutamate Biosensing With Nanocube And Nanosphere Augmented Single-Walled Carbon Nanotube Networks: A Comparative Study, Jonathan C. Claussen, Mayra S. Artiles, Eric S. Mclamore, Subhashree Mohanty, Jin Shi, Jenna L. Rickus, Timothy S. Fisher, D. Marshall Porterfield
Electrochemical Glutamate Biosensing With Nanocube And Nanosphere Augmented Single-Walled Carbon Nanotube Networks: A Comparative Study, Jonathan C. Claussen, Mayra S. Artiles, Eric S. Mclamore, Subhashree Mohanty, Jin Shi, Jenna L. Rickus, Timothy S. Fisher, D. Marshall Porterfield
Jonathan C. Claussen
We describe two hybrid nanomaterial biosensor platforms, based on networks of single-walled carbon nanotubes (SWCNTs) enhanced with Pd nanocubes and Pt nanospheres and grown in situ from a porous anodic alumina (PAA) template. These nanocube and nanosphere SWCNT networks are converted into glutamate biosensors by immobilizing the enzyme glutamate oxidase (cross-linked with gluteraldehyde) onto the electrode surface. The Pt nanosphere/SWCNT biosensor outperformed the Pd nanocube/SWCNT biosensor and previously reported similar nanomaterial-based biosensors by amperometrically monitoring glutamate concentrations with a wide linear sensing range (50 nM to 1.6 mM) and a small detection limit (4.6 nM, 3s). These results combined with …
Nanotechnology Education—First Step In Implementing A Spiral Curriculum, Ganesh Balasubramanian, Vinod K. Lohani, Ishwar K. Puri, Scott W. Case, Roop L. Mahajan
Nanotechnology Education—First Step In Implementing A Spiral Curriculum, Ganesh Balasubramanian, Vinod K. Lohani, Ishwar K. Puri, Scott W. Case, Roop L. Mahajan
Ganesh Balasubramanian
A nanotechnology learning module was implemented into a freshman engineering course at Virginia Tech. The novelty of our approach is that an established spiral curriculum model has been employed, for the first time to the best of authors’ knowledge, to design the nanotechnology option. The module was piloted in a freshman class (180 students) during spring ‘08. The key components included (1) a prior knowledge survey, (2) a 40-minute in-class presentation on basic nanotechnology concepts, (3) an activity that involves nanoscale image analysis and the plotting of molecular forces usingLabVIEWsoftware,and(4)apost-modulesurvey.Lessonslearnedfromthepilotimplementationwereincorporated appropriately to expose roughly 1450 freshmen to nanotechnology basics in …
Effects Of Carbon Nanotube-Tethered Nanosphere Density On Amperometric Biosensing: Simulation And Experiment, Jonathan C. Claussen, James B. Hengenius, Monique M. Wickner, Timothy S. Fisher, David M. Umulis, D. Marshall Porterfield
Effects Of Carbon Nanotube-Tethered Nanosphere Density On Amperometric Biosensing: Simulation And Experiment, Jonathan C. Claussen, James B. Hengenius, Monique M. Wickner, Timothy S. Fisher, David M. Umulis, D. Marshall Porterfield
Jonathan C. Claussen
Nascent nanofabrication approaches are being applied to reduce electrode feature dimensions from the microscale to the nanoscale, creating biosensors that are capable of working more efficiently at the biomolecular level. The development of nanoscale biosensors has been driven largely by experimental empiricism to date. Consequently, the precise positioning of nanoscale electrode elements is typically neglected, and its impact on biosensor performance is subsequently overlooked. Herein, we present a bottom-up nanoelectrode array fabrication approach that utilizes low-density and horizontally oriented single-walled carbon nanotubes (SWCNTs) as a template for the growth and precise positioning of Pt nanospheres. We further develop a computational …
Rh1−Xpdxnanoparticle Composition Dependence In Co Oxidation By Oxygen: Catalytic Activity Enhancement In Bimetallic Systems, James Russell Renzas, Wenyu Huang, Yawen Zhang, Michael E. Grass, Dat Tien Hoang, Selim Alayoglu, Derek R. Butcher, Franklin Tao, Zhi Liu, Gabor A. Somorjai
Rh1−Xpdxnanoparticle Composition Dependence In Co Oxidation By Oxygen: Catalytic Activity Enhancement In Bimetallic Systems, James Russell Renzas, Wenyu Huang, Yawen Zhang, Michael E. Grass, Dat Tien Hoang, Selim Alayoglu, Derek R. Butcher, Franklin Tao, Zhi Liu, Gabor A. Somorjai
Wenyu Huang
Bimetallic 15 nm Rh1−xPdxnanoparticle catalysts of five different compositions and supported on Si wafers have been synthesized, characterized using TEM, SEM, and XPS, and studied in CO oxidation by O2 in two pressure regimes: atmospheric pressure and 100–200 mTorr. The RhPd bimetallic nanocrystals exhibited similar synergetic effect of increased reaction activity at both atmospheric (760 Torr) and moderate (100–200 mTorr) pressures compared with pure Pd or Rh. The magnitude of the effect depends on the relative pressures of the CO and O2 reactant gases and the reaction temperature. The catalytic activity of the nanocrystals measured at moderate pressure is directly …