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A Stochastic Theory Of Inhomogeneously Broadened Linewidths In Solids, Ulrich Zürcher
A Stochastic Theory Of Inhomogeneously Broadened Linewidths In Solids, Ulrich Zürcher
Physics Faculty Publications
We investigate spectral diffusion decay using a model for solids that consists of two-level-systems (TLSs) interacting via strain fields. For the case when the rate of TLS flips vanishes, we find algebraic decay of correlation functions of the local field. We show that properties of equilibrium fluctuations are in agreement with the hierarchical picture proposed by Basché and Moerner: TLSs far away produce fast fluctuations that are small in magnitude, and close TLSs produce large fluctuations that are less frequent.
Room Temperature Aging Of Pd-Cu-Ga Dental Alloys, William A. Brantley, Zhuo Cai, Qiang Wu, Alan B. Carr, John C. Mitchell
Room Temperature Aging Of Pd-Cu-Ga Dental Alloys, William A. Brantley, Zhuo Cai, Qiang Wu, Alan B. Carr, John C. Mitchell
Cells and Materials
Specimens of three Pd-Cu-Ga dental alloys cast five years ago and subsequently stored at room temperature were reexamined and observed to have lower amounts of the eutectic constituents in the near-surface region than originally present, along with other microstructural changes. This previously unreported room temperature aging behavior of these alloys is attributed to the presence of high-diffusivity paths in the non-equilibrium ascast eutectic structures and to the essential role of the surface for the vacancy diffusion mechanism. These results may have important clinical significance for the ill vivo corrosion resistance and long-term biocompatibility of the Pd-Cu-Ga alloys.
Proton Diffusion In Nickel Hydroxide Films: Measurement Of The Diffusion Coefficient As A Function Of State Of Charge, Sathya Motupally, Christopher C. Streinz, John W. Weidner
Proton Diffusion In Nickel Hydroxide Films: Measurement Of The Diffusion Coefficient As A Function Of State Of Charge, Sathya Motupally, Christopher C. Streinz, John W. Weidner
Faculty Publications
Electrochemical impedance spectroscopy (EIS) was used to measure the solid-state diffusion coefficient of protons in nickel hydroxide films at room temperature as a function of state of charge (SOC). A model for the complex faradaic impedance of the nickel hydroxide active material is presented and used to extract the diffusion coefficient of protons from the EIS data. Impedance data over a range of frequencies can be used to extract a constant diffusion coefficient without the knowledge of the initial mobile proton concentration or the form of the charge-transfer kinetic expression. The proton diffusion coefficient is a strong function of SOC …
Electrochemical Determination Of The Diffusion Coefficient Of Hydrogen Through An Lani4.25Al0.75 Electrode In Alkaline Aqueous Solution, G. Zheng, Branko N. Popov, Ralph E. White
Electrochemical Determination Of The Diffusion Coefficient Of Hydrogen Through An Lani4.25Al0.75 Electrode In Alkaline Aqueous Solution, G. Zheng, Branko N. Popov, Ralph E. White
Faculty Publications
The constant potential and constant current discharge techniques were used to determine the hydrogen diffusion coefficients in an LaNi4.25Al0.75 electrode. The values obtained were 2.97 × 10–11 and 3.30 × 10–11 cm2/s, respectively. The advantages and disadvantages of these two techniques are discussed.
Electrochemical Determination Of The Diffusion Coefficient Of Hydrogen Through An Lani4.25Al0.75 Electrode In Alkaline Aqueous Solution, G. Zheng, Branko N. Popov, Ralph E. White
Electrochemical Determination Of The Diffusion Coefficient Of Hydrogen Through An Lani4.25Al0.75 Electrode In Alkaline Aqueous Solution, G. Zheng, Branko N. Popov, Ralph E. White
Faculty Publications
The constant potential and constant current discharge techniques were used to determine the hydrogen diffusion coefficients in an LaNi4.25Al0.75 electrode. The values obtained were 2.97 × 10–11 and 3.30 × 10–11 cm2/s, respectively. The advantages and disadvantages of these two techniques are discussed.
Technology Adoption In The Presence Of An Exhaustible Resource: The Case Of Groundwater Extraction, Ujjayant N. Chakravorty, Farhed Shah, David Zilberman
Technology Adoption In The Presence Of An Exhaustible Resource: The Case Of Groundwater Extraction, Ujjayant N. Chakravorty, Farhed Shah, David Zilberman
Ujjayant Chakravorty
In this paper we integrate technology diffusion within Hotelling's exhaustible resource model. The modern technology is a conservation technology such as drip irrigation used with groundwater. Resource quality heterogeneity and rising water prices are responsible for the gradual adoption of the modern technology, and under reasonable conditions the diffusion curve is an S-shaped function of time. Without intervention, the diffusion process will be slower than is socially optimal, and optimal resource use tax will accelerate the diffusion of the conservation technology and slow down excessive resource depletion caused by market failure due to open access conditions.