Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1131&context=usdoepub

A review of polymer electrolyte membrane fuel cells: Technology, applications,and needs on fundamental research

▪ Abstract Proton-coupled electron transfer (PCET) is an important mechanism for charge transfer in a wide variety of systems including biology- and materials-oriented venues. We review several are...

/pdf/proton-coupled-electron-transfer-3oyvp0w9qd.pdf

Proton-Coupled Electron Transfer

Fluid dynamic turbulence is one of the most challenging computational physics problems because of the extremely wide range of time and space scales involved, the strong nonlinearity of the governing equations, and the many practical and important applications. While most linear fluid instabilities are well understood, the nonlinear interactions among them makes even the relatively simple limit of homogeneous isotropic turbulence difficult to treat physically, mathematically, and computationally. Turbulence is modeled computationally by a two-stage bootstrap process. The first stage, direct numerical simulation, attempts to resolve the relevant physical time and space scales but its application is limited to diffusive flows with a relatively small Reynolds number (Re). Using direct numerical simulation to provide a database, in turn, allows calibration of phenomenological turbulence models for engineering applications. Large eddy simulation incorporates a form of turbulence modeling applicable when the large-scale flows of interest are intrinsically time dependent, thus throwing common statistical models into question. A promising approach to large eddy simulation involves the use of high-resolution monotone computational fluid dynamics algorithms such as flux-corrected transport or the piecewise parabolic method which have intrinsic subgrid turbulence models coupled naturally to the resolved scales in the computed flow. The physical considerations underlying and evidence supporting this monotone integrated large eddy simulation approach are discussed.

New insights into large eddy simulation

A review of water flooding issues in the proton exchange membrane fuel cell

A mesoscale simulation is developed to simulate transport and electrochemistry in a small section of a proton exchange membrane fuel cell (PEMFC) cathode catalyst layer. Oxygen, proton, and electron transport are considered in the model. Many simulations are run with a wide variety of different parameters on stochastically reconstructed microstructures with a resolution of 2 nm. Knudsen diffusion plays an important role in limiting the transport of oxygen through the catalyst layer. Using larger carbon spheres in the catalyst layer increases the effective diffusivity of oxygen through the catalyst layer. The effective proton conductivity increases when larger spheres are used, a normal distribution of spheres is used, or a higher overlap tolerance is used. Increasing the overlap tolerance or overlap probability results in an increase in the effective electron conductivity. When electrochemical reactions are considered in a part of the catalyst layer that is close to the gas diffusion layer, the critical parameter that determines oxygen consumption is the carbon sphere radius. Oxygen consumption at a given carbon volume fraction is larger in microstructures containing spheres with smaller radii, because there is more surface area available for electrochemical reactions.

Pore Scale Simulation of Transport and Electrochemical Reactions in Reconstructed PEMFC Catalyst Layers

https://www.engr.uvic.ca/~ndjilali/Papers/JPS_Zhu%20et%20al_2008_Preprint.pdf

Three-dimensional numerical simulations of water droplet dynamics in a PEMFC gas channel

Dynamic behaviour of liquid water emerging from a GDL pore into a PEMFC gas flow channel

Transient non-isothermal model of a polymer electrolyte fuel cell

With the increasing market share of lithium-ion battery in the secondary battery market and their applications in electric vehicles, the recycling of the spent batteries has become necessary. The number of spent lithium-ion batteries grows daily, which presents a unique business opportunity of recovering and recycling valuable metals from the spent lithium-ion cathode materials. Various metals including cobalt, manganese, nickel, aluminum, and lithium can be extracted from these materials through leaching with chemicals such as hydrochloric acid ( HCl ), nitric acid ( HN O 3 ), sulfuric acid ( H 2 S O 4 ), oxalate ( H 2 C 2 O 2 ), DL-malic acid ( C 4 H 5 O 6 ), citric acid ( C 6 H 8 O 7 ), ascorbic acid ( C 6 H 8 O 6 ), phosphoric acid ( H 3 P O 4 ) or acidithiobacillus ferrooxidans. This paper provides a comprehensive review on the available hydrometallurgical technologies for recycling spent lithium-ion cathode materials. The recycling processes, challenges and perspectives reported to date and recycling companies in the market are summarized. To accelerate the development of battery recycling technology toward commercialization, some potential research directions are also proposed in this paper.

Pang-Chieh Sui

Papers

Pore Scale Simulation of Transport and Electrochemical Reactions in Reconstructed PEMFC Catalyst Layers

Three-dimensional numerical simulations of water droplet dynamics in a PEMFC gas channel

Dynamic behaviour of liquid water emerging from a GDL pore into a PEMFC gas flow channel

Transient non-isothermal model of a polymer electrolyte fuel cell

A review of recycling spent lithium-ion battery cathode materials using hydrometallurgical treatments