Publications by authors named "Jeng-Rong Ho"

This study investigates the effect of laser volume energy density (VED) on the properties of AISI 420 stainless steel and TiN/AISI 420 composite manufactured by selective laser melting (SLM). The composite contained 1 wt.% TiN and the average diameters of AISI 420 and TiN powders were 45 µm and 1 µm, respectively.

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The purpose of this study is to investigate the effects of laser spot size on the mechanical properties of AISI 420 stainless steel, fabricated by selective laser melting (SLM), process. Tensile specimens were built directly via the SLM process, using various laser spot diameters, namely 0.1, 0.

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Mechanical properties and microstructure are investigated for a martensitic stainless steel (AISI 420) fabricated by selective laser melting (SLM) in three build directions. The tensile specimens built by SLM are classified into three groups. Group A is horizontally built in the thickness direction, Group B is horizontally built in the width direction, and Group C is vertically built in the length direction.

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Using poly(3-hexylthiophene) (P3HT) covalently bonded with carbon nanotubes (CNT) as an active layer in a bottom-gate/top contact, Au/(P3HT)/(bilayer dielectric)/Si OTFT device has resulted in an enhanced charge transport. The CNTs were firstly functionalized via ligand exchange with ferrocene, next lithiated by sec-butyllithium (s-BuLi) and then linked anionically with P3HT which has been synthesized via the modified Grignard metathesis method. Compared to the pristine P3HT, the CNTs-containing P3HT composite material has a higher energy level of HOMO and a smaller electrochemical bandgap E(g)(chem).

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The charge transport enhancement of using poly(3-hexylthiophene) covalently bonded with gold nanoparticles as an active layer in a bottom-gate/top contact, Au/(P3HT)/(bilayer dielectric)/Si OTFT device has been studied. P3HT was synthesized via the modified Grignard metathesis method and functionalized to have a thiol terminal (P3HT(SH)). Gold nanoparticles (AuNPs) with sizes ranging from 2 to 10 nm were then formed via a reduction of HAuCl4 in the presence of P3HT(SH).

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Lattice-Boltzmann modeling of phonon hydrodynamics.

Phys Rev E Stat Nonlin Soft Matter Phys

June 2008

Based on the phonon Boltzmann equation, a lattice-Boltzmann model for phonon hydrodynamics is developed. Both transverse and longitudinal polarized phonons that interact through normal and umklapp processes are considered in the model. The collision term is approximated by the relaxation time model where normal and umklapp processes tend to relax distributions of phonons to their corresponding equilibrium distribution functions-the displaced Planck distribution and the Planck distribution, respectively.

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