Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
- Publication
Articles 1 - 9 of 9
Full-Text Articles in Engineering
Structure And Intermicellar Interactions In Block Polyelectrolyte Assemblies, Surita Bhatia, M. A. Crichton
Structure And Intermicellar Interactions In Block Polyelectrolyte Assemblies, Surita Bhatia, M. A. Crichton
Surita Bhatia
Amphiphilic diblock polyelectrolytes are becoming popular in industrial applications due to their versatility, ranging from usage in pharmaceuticals to personal care products. Many of these systems also exhibit interesting rheological and morphological behavior. Our system is based on a polystyrene-poly(ethyl acrylate) diblock. The properties can be tuned by utilizing a simple hydrolysis reaction, converting poly(ethyl acrylate) (PEA) to poly(acrylic acid) (PAA). We study the effect of this hydrolysis reaction on the interaction between micelles of polystyrene-poly(acrylic acid) in water using small-angle and ultra-small-angle neutron scattering. We see that as more PEA is converted to PAA, the aggregation number and polystyrene …
Low-Density Parity-Check Codes For Volume Holographic Memory Systems, Hossein Pishro-Nik, Nazanin Rahnavard, Jeongseok Ha, Faramarz Fekri, Ali Adibi
Low-Density Parity-Check Codes For Volume Holographic Memory Systems, Hossein Pishro-Nik, Nazanin Rahnavard, Jeongseok Ha, Faramarz Fekri, Ali Adibi
Hossein Pishro-Nik
We investigate the application of low-density parity-check (LDPC) codes in volume holographic memory (VHM) systems. We show that a carefully designed irregular LDPC code has a very good performance in VHM systems. We optimize high-rate LDPC codes for the nonuniform error pattern in holographic memories to reduce the bit error rate extensively. The prior knowledge of noise distribution is used for designing as well as decoding the LDPC codes. We show that these codes have a superior performance to that of Reed-Solomon (RS) codes and regular LDPC counterparts. Our simulation shows that we can increase the maximum storage capacity of …
Raney Ni-Sn Catalyst For H2 Production From Biomass-Derived Hydrocarbons, George W. Huber, J. W. Shabaker, J. A. Dumesic
Raney Ni-Sn Catalyst For H2 Production From Biomass-Derived Hydrocarbons, George W. Huber, J. W. Shabaker, J. A. Dumesic
George W. Huber
Hydrogen (H2) was produced by aqueous-phase reforming of biomass-derived oxygenated hydrocarbons at temperatures near 500 kelvin over a tin-promoted Raney-nickel catalyst. The performance of this non–precious metal catalyst compares favorably with that of platinum-based catalysts for production of hydrogen from ethylene glycol, glycerol, and sorbitol. The addition of tin to nickel decreases the rate of methane formation from C-O bond cleavage while maintaining the high rates of C-C bond cleavage required for hydrogen formation.
Aqueous-Phase Reforming Of Ethylene Glycol Over Supported Platinum Catalysts, George W. Huber, J W. Shabaker, R. R. Davda, R. D. Cortright, J. A. Dumesic
Aqueous-Phase Reforming Of Ethylene Glycol Over Supported Platinum Catalysts, George W. Huber, J W. Shabaker, R. R. Davda, R. D. Cortright, J. A. Dumesic
George W. Huber
Aqueous-phase reforming of 10 wt% ethylene glycol solutions was studied at temperatures of 483 and 498 K over Pt-black and Pt supported on TiO2, Al2O3, carbon, SiO2, SiO2-Al2O3, ZrO2, CeO2, and ZnO. High activity for the production of H2 by aqueous-phase reforming was observed over Pt-black and over Pt supported on TiO2, carbon, and Al2O3 (i.e., turnover frequencies near 8-15 min-1 at 498 K); moderate catalytic activity for the production of hydrogen is demonstrated by Pt supported on SiO2-Al2O3 and ZrO2 (turnover frequencies near 5 min-1); and lower catalytic activity is exhibited by Pt supported on CeO2, ZnO, and SiO2 …
Nonlinear Parameter Estimation For Solution–Diffusion Models Of Membrane Pervaporation, Bing Cao, Michael A. Henson
Nonlinear Parameter Estimation For Solution–Diffusion Models Of Membrane Pervaporation, Bing Cao, Michael A. Henson
Michael A Henson
An optimization-based procedure for estimating unknown parameters in solution–diffusion models of membrane pervaporation is presented. Permeation of two components through a polymer membrane is described by distinct solution and diffusion models. The solution model is based on a modified form of Flory–Huggins theory that accounts for interactions between the two penetrants. The diffusion model is derived from Fick’s law, where the diffusion coefficients are allowed to depend on the local concentration of each component in the membrane. A phenomenologic relation is used to account for the effect of temperature on the component fluxes. The solution and diffusion models, as well …
Macromolecules In The 21st Century: An International Symposium On Polymer Science And Technology On The Occasion Otto Vogl's 75th Birthday, Gerald S. Kirshenbaum, Helga Roder
Macromolecules In The 21st Century: An International Symposium On Polymer Science And Technology On The Occasion Otto Vogl's 75th Birthday, Gerald S. Kirshenbaum, Helga Roder
Otto Vogl
No abstract provided.
2dsim: A Prototype Of Nanoscopic Traffic Simulation, Daiheng Ni
2dsim: A Prototype Of Nanoscopic Traffic Simulation, Daiheng Ni
Daiheng Ni
This paper reviews and compares car-following and lane- changing logics embedded in some microscopic traffic simulation models, and comments are made on the existing techniques of traffic simulation. Future directions of traffic simulation are identified in three aspects: vehicle modeling, driver modeling, and vehicle movement modeling. To illustrate these ideas, a conceptual model, 2DSIM, is proposed, which consists of a dynamic vehicle sub-model and an intelligent driver sub-model. They are further integrated into a driver-vehicle-environment closed-loop system which constitutes the basic building block of road traffic.
Simulation Of Freeway Merging And Diverging Behavior, Daiheng Ni, John D. Leonard
Simulation Of Freeway Merging And Diverging Behavior, Daiheng Ni, John D. Leonard
Daiheng Ni
Simplified theory of kinematic waves was proposed by Newell and uses cumulative arrival and departure counts to describe kinematic waves of freeway traffic. The original paper deals only with traffic on freeway mainline. It is of great interest, at least practically, to investigate whether the simplified theory can be used to simulate freeway traffic merging and diverging behavior. In his paper, Newell as- sumed that on-ramp traffic always has the priority and can bypass queues, if any. This assumption will be released so that traffic from the mainline and the on-ramp will have to compete for downstream supply. For off-ramps, …
Periodic Broadcast And Patching Services - Implementation, Measurement And Analysis In An Internet Streaming Video Testbed, Mk Bradshaw, B Wang, S Sen, Lx Gao, J Kurose, P Shenoy, D Towsley
Periodic Broadcast And Patching Services - Implementation, Measurement And Analysis In An Internet Streaming Video Testbed, Mk Bradshaw, B Wang, S Sen, Lx Gao, J Kurose, P Shenoy, D Towsley
Lixin Gao
No abstract provided.