Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 5 of 5

Full-Text Articles in Mechanical Engineering

Ultrasound-Assisted Synthesis Of Mesoporous Β-Ni(Oh)2 And Nio Nano-Sheets Using Ionic Liquids, Tarek Alammar, Osama Shekhah, Jonas Wohlgemuth, Anja V. Mudring Jan 2012

Ultrasound-Assisted Synthesis Of Mesoporous Β-Ni(Oh)2 And Nio Nano-Sheets Using Ionic Liquids, Tarek Alammar, Osama Shekhah, Jonas Wohlgemuth, Anja V. Mudring

Anja V. Mudring

Via a facile ultrasound synthesis from nickel acetate and sodium hydroxide with ionic liquids as the solvent and template it is possible to obtain nano-β-Ni(OH)2 of various dimensionalities depending on the reaction conditions with the ionic liquid (IL) being the most important factor. Scanning electron microscopy (SEM) imaging showed β-Ni(OH)2 to form as nanosheets, nanorods and nanospheres depending on the IL. ILs with strong to moderate hydrogen bonding capability like [C3mimOH][Tf2N] (1-(3-hydroxypropyl)-3-methylimidazolium bis(trifluoromethanesulfonylamide)), [C4mim][Tf2N] (1-butyl-3-methylimidazolium bis(trifluoromethanesulfonylamide)) and [Edimim][Tf2N] (1-ethyl-2,3-diemethylimidazolium bis(trifluoromethanesulfonylamide)) lead to the formation of nanosheets whilst ...


The Development And Implementation Of A Nanotechnology Module Into A Large, Freshman Engineering Course, Vinod Lohani, Ganesh Balasubramanian, Ishwar Puri, Scott Case, Roop Mahajan Jan 2009

The Development And Implementation Of A Nanotechnology Module Into A Large, Freshman Engineering Course, Vinod Lohani, Ganesh Balasubramanian, Ishwar Puri, Scott Case, Roop Mahajan

Ganesh Balasubramanian

The development and implementation of a nanotechnology learning module into a freshman engineering course in Virginia Tech’s large engineering program is discussed. This module, a part of a spiral theory based nanotechnology option that will be implemented in the curriculum of the Engineering Science Mechanics (ESM) department at Virginia Tech, was piloted with ~180 freshmen in Spring ’08. The pilot included a prior knowledge survey, a 40-minute in-class presentation on nanotechnology, a hands-on module involving analysis of nanoscale images, plotting of force functions at atomic scale using LABVIEW, and a post-module survey. Students’ misconceptions, observed through the prior knowledge ...


Unsteady Nanoscale Thermal Transport Across A Solid-Fluid Interface, Ganesh Balasubramanian, Soumik Banerjee, Ishwar K. Puri Sep 2008

Unsteady Nanoscale Thermal Transport Across A Solid-Fluid Interface, Ganesh Balasubramanian, Soumik Banerjee, Ishwar K. Puri

Ganesh Balasubramanian

We simulate unsteady nanoscale thermal transport at a solid-fluidinterface by placing cooler liquid-vapor Ar mixtures adjacent to warmer Fe walls. The equilibration of the system towards a uniform overall temperature is investigated using nonequilibrium molecular dynamics simulations from which the heat flux is also determined explicitly. The Ar–Fe intermolecular interactions induce the migration of fluid atoms into quasicrystallineinterfacial layers adjacent to the walls, creating vacancies at the migration sites. This induces temperature discontinuities between the solidlikeinterfaces and their neighboring fluid molecules. The interfacial temperature difference and thus the heat flux decrease as the system equilibrates over time. The averaged ...


A Fully Lagrangian Numerical Method For Calculating The Dynamics Of Oscillating Micro And Nanoscale Objects Immersed In Fluid, Nicole N. Hashemi, Mark Paul, Javier Alcazar, Raul Radovitzky Jan 2007

A Fully Lagrangian Numerical Method For Calculating The Dynamics Of Oscillating Micro And Nanoscale Objects Immersed In Fluid, Nicole N. Hashemi, Mark Paul, Javier Alcazar, Raul Radovitzky

Nastaran Hashemi

Many micro and nano-technologies rely upon the complicated motion of objects immersed in a viscous fluid. It is often the case that for such problems analytical theory is not available to quantitatively describe and predict the device dynamics. In addition, the numerical simulation of such devices involves moving boundaries and use of the standard Eulerian computational approaches are often difficult to implement. In order to address this problem we use and validate a fully Lagrangian finite element approach that treats the moving boundaries in a natural manner. We validate the method for use in calculating the dynamics of oscillating objects ...


Static Friction And Surface Roughness Studies Of Surface Micromachined Electrostatic Micromotors Using An Atomic Force/Friction Force Microscope, Sriram Sundararajan, Bharat Bhushan Jan 2001

Static Friction And Surface Roughness Studies Of Surface Micromachined Electrostatic Micromotors Using An Atomic Force/Friction Force Microscope, Sriram Sundararajan, Bharat Bhushan

Sriram Sundararajan

A technique to measure the static friction forces (stiction) encountered in surface micromachined micromotors using a commercial atomic force microscope (AFM)/friction force microscope has been developed and is described. An AFM tip is pushed against a rotor arm of the micromotor so as to generate lateral deflection (torsion) of the tip, which is measured by the AFM. The maximum value of the lateral deflection obtained prior to rotor movement (rotation) is a measure of the static friction force of the micromotors. This technique was employed to study the effect of humidity and rest time on the static friction force ...