bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microscale Fuel Cells for Portable Power Applications
Authors: Miller Kelly L , Burbules Mary Beth , DeLaney Scott C , Hollinger Adam S 
Published: February 2020

The development of microscale fuel cells has been motivated by the increasing demand for high power density, portable electronic devices (i.e., smartphones, tablet computers) with a fast recharge [1]. In comparison to rechargeable batteries, microscale fuel cells demonstrate superior energy densities and the potential to provide longer off-grid run times [2]. Additionally, fuel cells enable nearly instantaneous recharging by refilling or replacing a liquid-based fuel cartridge. However, due to the size constraints and power demands of modern portable electronic devices, microscale fuel cells must be optimized to produce sufficient power for as long as possible before requiring refilling or replacing of a self-contained fuel cartridge. To perform this optimization, parameters such as catalyst area, catalyst loading, fuel molarity, temperature, and flow rate, electrolyte molarity and flow rate, and electrode geometry are modified, isolated, and tested experimentally until maximum performance is achieved.
Because the aforementioned process is laborious, we present a mathematical flow and diffusion model to simulate the effects of the experimental parameters [3]. The model outputs performance data, confirmed by experimental data, over a range of parameters without the use of curve fitting, resulting in significantly improved simulation accuracy compared to simple curve fits. The model is adjusted to replicate the experimental results for a given set of parameters by adjustment of a set of internal variables. Utilizing a design of experiment (DOE)-based analysis of the model’s governing equation, the model is modified to simulate other experimental parameters accurately, resulting in a tool for microscale direct methanol fuel cell (DMFC) optimization. DOE experimental protocol reveals interactions between parameters and ultimately, a more complete understanding of DMFC performance parameters.
[1] E. Kjeang, N. Djilali, D. Sinton, Journal of Power Sources, 186 (2009) 353-369.
[2] C. Potera, Environ. Health Perspect., 115 (2007) A38-A41.
[3] A.S. Hollinger, M.G. Willis, D.G. Doleiden, Proceedings of the ASME 2015 Power and Energy Conversion Conference, San Diego, CA, 2015.
Integrating Ultrafast Coherent Diffractive Imaging and Atomistic Simulations to Investigate Externally Stimulated Metallic Nanocrystals
Authors: Sasikumar Kiran , Cherukara Mathew , Clark Jesse N , Peterka Tom , Harder Ross , Sankaranarayanan Subramanian K. R. S. 
Published: February 2020

Despite the increasing role of nanomaterials in technology, the mechanical and dynamical properties of single nanoparticles at picosecond timescales are not well understood. In particular, core-shell nanocrystals are an important class of nanoparticles for catalysis, biomedical and energy applications. The effect of the nanoscale interface between the core and shell material on coherent lattice vibrations (phonons) is yet to be investigated in detail. Understanding the temporal behavior of such nanomaterials under conditions of external thermal stimulation is crucially important for energy research. In addition, observing ultrafast lattice distortions can provide key insights into the behavior of nanomaterials and nanoscale interfaces.
Recently, experimental techniques have evolved to conduct time-dependent lattice dynamics measurements in nanomaterials. In particular, Bragg Coherent Diffraction Imaging (BCDI) in conjunction with optical pump-probe experiments via ultrafast x-ray lasers has been used to directly image the generation and subsequent evolution of coherent acoustic phonons within nanocrystals. In particular, experiments on bimetal (Au/Al) core-shell nanocrystals have revealed inhomogeneous effects in the lattice breathing upon heating with femtosecond x-ray lasers. Conventional theoretical models cannot be used to explain the physics of the phenomena in such non-equilibrium environments that involve extreme heat fluxes and temperature gradients.
Atomistic molecular dynamics (MD) simulation is an appropriate technique to investigate lattice dynamics in such environments, particularly in core-shell structures where interfacial effects can play an important role in phonon scattering. With the convergence of time and length scales accessible by both experiments and simulations, we are now able to integrate experimental observations with multi-million atom MD simulations to enhance the fundamental understanding of materials behavior under external stimulation.
In this talk, we demonstrate the workflow to integrate ultrafast time-resolved coherent diffractive imaging with large-scale atomistic molecular dynamics simulations to investigate lattice dynamics in externally stimulated core-shell bimetallic nanocrystals. We will focus, primarily, on the MD simulations performed on core-shell bimetallic nanocrystals under the influence of extreme heat fluxes. We explore the vibrational modes that dominate lattice breathing and look into the effect the nanoparticle size and shape have on the same. In addition, we attempt to identify the origin of the inhomogeneous effects, observed experimentally, in the lattice breathing of core-shell structures.

Figure 1
from Bare Metals to Metal Oxides Nanoparticles and Hierarchical Supramolecular Metal Oxide Nanoparticle Network Assemblies
Authors: Redel Engelbert 
Published: February 2020

A unique, universal and general route to a library of different metal oxide nanoparticle materials starting from bare metal powders will be presented. Such metal oxide nanoparticles are further used to construct porous and hierarchical photonic multilayer assemblies or can be assembled into 1D supramolecular nanoparticle network structures.
Potential applications of such materials will be also presented, reaching from optical and tune able and porous 1D photonic crystals (PCs) to transparent and conductive oxides (TCOs) porous thin films, electrochromo-photonic switches as well as sensing devices.

REFERENCES:

E. REDEL, P. MIRTCHEV, C. HUAI, S. PETROV, G. A. OZIN
Nanoparticle Films and Photonic Crystal Multilayers from Colloidal Stable, Size-Controllable Zinc and Iron Oxide Nanoparticles. ACS NANO, 2011, 5, 2861-2869.
E. REDEL, S. PETROV, D. OMER, J. MOIR, C. HUAI, P. MIRTCHEV, G. A. OZIN
From Metal Powders to Metal Oxide Nanoparticles and Porous Thin Films.

SMALL
2012, 8, 68-72.
E. REDEL, J. MLYNARSKI, J. MOIR, A. JELLE, C. HUAI, S. PETROV, M. G. HELANDER, F. C. PEIRIS, G. V. FREYMANN, G. A. OZIN
“Electrochromic Bragg Mirror (ECBM)” Advanced Materials
2012, 24, OP265-OP269.
S. MAKUMIREA, V. S. K. CHAKRAVADHANULA, E. REDEL, A. SHONHAI
“The effect of colloidal and charge stabilized Zinc peroxide (ZnO2) and Titanium dioxide (TiO2) nanoparticles on the structural integrity of DNA and protein”

Toxicology Letters
2014, 227, 56-64.
E. REDEL, V. S. K. CHAKRAVADHANULA, Y. LANHUA, C. NATZEK, S. HEISSLER
“On the self-assembly of paramagnetic TiOx NPs to supramolecular TiO2 network structures”

Nanotechnology
2015, 26
, 051001.
Electrochemical Characterization of Lithium-Oxygen Cells Employing a Bi-Functional Metal-Free Catalyst Composed of Dual-Doped Graphene and Mesoporous Carbon
Authors: Kim Jae-Hong , G Kannan Aravindaraj , Woo Hyun-Sik , Kim Dong-Won 
Published: February 2020

Rechargeable lithium-oxygen (Li-O2) batteries have received great attention due to their high theoretical energy density. The successful operation of the Li-O2 battery requires the reversible formation and decomposition of insoluble Li2O2 on the cathode surface during the discharge and charge processes. However, the large overpotential during the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) should be reduced to make this battery commercially viable. Recently, carbon-based nanomaterials have been widely explored as either a catalyst support or a catalyst for the ORR in different electrolytes. In particular, graphene nanosheets with their two-dimensional, sp2-hybridized carbon structure have received great interest due to desirable properties such as high surface area, high electronic conductivity and charge carrier mobility, high mechanical strength and chemical stability. In this work, mesoporous carbon was grown on graphene nanosheets by in situ nitrogen and sulfur co-doping using a two-step synthesis method (hereafter referred to as NSGC). The growth of mesoporous carbon on graphene nanosheets prevented the restacking of graphene, resulting in a higher active surface area and enhanced electronic conductivity. Furthermore, the presence of mesoporous structures could accommodate the insoluble Li2O2 formed during discharge. As a result, the synthesized NSGC exhibited enhanced bi-functional catalytic activities toward ORR and OER, and showed a high initial discharge capacity of 11,431 mAh g-1 and good cycling stability as an air cathode in Li-O2 batteries.
Gold Nanoparticles Supported over Low-Cost Adsorbents for Hydrogen Generation from a Solid Hydrogen Feedstock
Authors: Abdel-Fattah Tarek M , Horten Mitchell , Osborn Justin 
Published: February 2020

Due to the rising concern of global warming and the limited supply of fossil fuels, hydrogen gas production for use as a clean and renewable energy source has been a rapidly growing field of research. A significant amount of work has been done in generating hydrogen gas from water [1-3]. However, this is an energy intensive process. Solid chemical storage of hydrogen using metal hydrides has been proposed as an attractive alternative. Sodium borohydride is considered one of the most viable hydrogen storage materials because it provides a safe and practical means of producing hydrogen and has a high hydrogen content (10.7% wt). Sodium borohydride produces hydrogen by slowly reacting with water to evolve 4 moles of hydrogen gas [3]. While a slow reaction is favorable for reduction, the use of sodium borohydride to produce hydrogen gas for energy generation necessitates the use of catalysis to accelerate the reaction to an appreciable rate. A significant amount of research has been conducted searching for catalysts of such reactions, often finding noble metals to be the most efficient. Nobel metals are often expensive, therefore price must be considered when deciding on a catalyst. A cost effective strategy to create noble metal catalysts is to synthesize nanoparticles of the metal of interest and adsorb them to low-cost supports.
Gold nanoparticles affixed to activated carbon and glasswool were tested for catalytic activity in the hydrogen evolution reaction of aqueous sodium borohydride and compared against the catalytic activity of uncoated activated carbon and glasswool supports. The evolved gas was measured through the use of a water-displacement system, Ohaus microbalance, and mass logging software. Preliminary data suggests that the gold nanoparticle supports are more efficient at generating hydrogen than non-coated substrates.

References:

[1] Abdel-Fattah T. M.; Wixtrom A. Catalytic Reduction of 4-Nitrophenol Using Nanoparticles on Carbon Nanotubes. 2014,
ECS J SOLID STATE SC 3(4) M18-M20.
[2] Schlesinger, H.; Brown, H.; Finholt, A.; Gilbreath, J.; Hoekstra, H.; Hyde, E. Sodium Borohydride, Its Hydrolysis and its Use as a Reducing Agent and in the Generation of Hydrogen. 1952,
J. Am. Chem. Soc. 75(1) 215-219.
[3[ Zahmakiran, M.; Özkar, S. Zeolite-Confined Ruthenium(0) Nanoclusters Catalyst: Record Catalytic Activity, Reusability, and Lifetime in Hydrogen Generation from the Hydrolysis of Sodium Borohydride. 2009, Langmuir. 25(5) 2667-2678.
Controlled Synthesis of BaTiO3 Nanofibers for Enhanced Piezoelectric Properties
Authors: Shirazi Paymon , Anderson Christopher S. , Ma Meghann C. , Myung Nosang Vincent 
Published: February 2020

Reducing the size of piezoelectric energy harvesting devices – progressing from bulk materials, through the micro scale, and now into the nanoscale – is attracting interest in new size-based classifications of clean energy sources converting ambient, attenuated mechanical energy into electrical energy. Compared to the macro devices, nanostructures based transducer materials, with their exclusively large surface area-to-volume ratio, have shown enhanced piezoelectric properties. In this paper, electrospinning was used to fabricate nanofibrous structures by jetting a solution of barium and titanium precursors dissolved in poly (vinyl pyrrolidone) (PVP) with an applied voltage. Three separate full-factorial design of experiments (DOEs) (one 3-level, two 2-levels) were conducted to control and optimize the process to minimize fiber diameter with the least amount of beading defects. The three factor design focused on the optimization of the solution properties (viscosity, electrical conductivity, surface tension), one of the two factors focused on electrospinning parameters (voltage, flow rate), and the other on environmental conditions (temperature, absolute humidity). The viscosity was controlled by the polymer weight percentage, the electrical conductivity controlled by the salt to polymer ratio, and the surface tension controlled by the solvent. Low temperature and low absolute humidity produced the smallest fibers. Scanning electron microscopy (SEM) was utilized to characterize the morphology and diameter of the as-spun nanofibers. Micrographs of our best results showed as-spun nanofibers with an average diameter of 74.6 ± 15 nm with minimal beading. The as-spun nanofiber mats were subsequently calcinated and annealed to produce BaTiO3 nanofibers to be tested for their piezoelectric properties.
A Study on Profile Control at Wafer Edge By CMP Head Separated Retainer Ring
Authors: Yoo Jinsu , Lee Dongjun , Yoon Hyunjoo , Jeon Joonbae , Kim Kyoungwoo , Hwang Hasub 
Published: February 2020

CMP (chemical mechanical planarization) is a process in which both chemical and mechanical mechanisms act simultaneously to produce the planarized wafer.[1]
The wafer edge profile control is the most challenging issue in CMP process. Even much investigation has been tried to eliminate wafer edge profile control, the understanding the origins of the wafer edge profile control during polishing are still needed.
Fig1. shows the differences were compared with the single retainer ring and separated retainer ring.
Fig2. shows that the separated retainer ring can control wafer edge profile as the result of the simulation.
Fig3. is the removed wafer normalize amount as compared with the result of single retainer ring and separated retainer ring.
In this study, we examined the better wafer edge profile control was presented by changing the original form of RR(retainer ring) into having two individual pressure controls.
Based on experimental and simulation result, it was possible to achieve uniform surface even in the wafer edge area in the case of separated retainer ring by decreasing pad deformation.
REFERENCE
1. P. Singer, “Chemical-Mechanical Polishing : A new focus on consumable”, Semiconductor International, pp. 48-53, Feb, 1994.
2. Preston, F. W., “The Theory and Design of Plate Glass Polishing Machine”. Journal of the Society of Glass Technology, 11, p. 214, 1927.
3. Zhao, D., Wang, T., He, Y., and Lu, X., “Effect of Zone Pressure on Wafer Bending and Fluid Lubrication Behavior during Multi-zone CMP Process”, Microelectronic Engineering, 108, p. 33, 2013.
4. Wang, T., Lu, X., Zhao, D., & He, Y., "Contact Stress Non-uniformity of Wafer Surface for Multi-zone Chemical Mechanical Polishing Process." Science China Technological Sciences, 56(8), p.1974, 2013.

Figure 1
Electrochemistry Modeling for Energy Conversion and Storage
Authors: Lueth Chris 
Published: February 2020

Renewable energy devices, such as fuel cells, flow batteries, and electrolyzers require reliable functioning of mass and energy transfer processes. For example, water management in fuel cells is tightly linked to their thermal and electrochemical operation. To better understand and predict these interactions, computer aided engineering (CAE) may provide a valuable tool. CAE in parallel with experimentation has proven invaluable for efficient design and theoretical insight in traditional engineering fields like automotive and aerospace. In many instances, it has even replaced the need for expensive prototyping. Combing the traditional flow, stress, and thermodynamic models with electrochemistry may provide the innovation required for the development of renewable energy technology and processes.
We will present recent electrochemistry developments in an industrial CAE software. The general framework provides unprecedented flexibility with the range of physics and length scales available with an extensive suite of compatible models. The general implementation allows for simulation of a wide array of processes, from pH effects on corrosion to water management in fuel cells.
Electrospun Polyimide Based Composite Fibrous Separator with High Heat Resistance for Lithium Ion Batteries
Authors: Jo Seong Mu , Joh Han-Ik , Lee Sungho 
Published: February 2020

High heat-resistive nanofibrous membrane as new separator of future lithium ion battery was prepared by electrospinning of PVdF and Polyimide(PI) mixture solution. Electrospun PI/PVdF composite fibrous separators generally have mechanical performance with tensile strength of 32 MPa, and modulus of 700 MPa after post-process such as hot-pressing. The internal structure of the electrospun PVdF/PI composite fiber with a diameter of few hundreds nanometer were composed of a bundle of PI nanofiber with a diameter of few tens nanometer, which resulted from microphase separation and highly stretching of PI micro-domain during electrospinning. These composite fibrous separator show high ionic conductivity of 1.3× 10-3 S/cm at room temperature and sufficient electrochemical stability windows above 4.5 V ver. Li+/Li. From thermal stability tests, PE separator was melted above 130oC, but PI/PVdF blend membranes show good dimensional stability at above 200 oC. It indicates the membrane will still retain the mechanical integrity of membrane even after meltdown at high temperature. Also, the prototype cells with electrospun PI/PVdF composite membrane have good long term cycle performance over 500 cycles compared with PE separator at 1C rate.
Hydrogen Trap in Seashells
Authors: Kato Yoshimine , Tsuchida Hirotsugu , Dobara Kent , Aramaki Masatoshi , Furukimi Osamu 
Published: February 2020

Hydrogen evolution and adsorption were found that from seashells at high temperature. Large quantities of seashells are abandoned as production waste and it is desired to make use of them. As it is well known that the component of seashell is mostly calcium carbonate CaCO3 layers which are bonded by conchiolin layers. In conchiolin layers there are many types of carbohydrates and those seem to be origin of hydrogen evolution during the heat treatment in N2 gas flow at temperature between 300 and 900°C. Hydrogen gas detection was conducted with gas chromatography mass spectrometer during the heat treatment flowing Ar gas of 50ml/min. The total evolution hydrogen amount from the Mizuhopecten yessoensis［scallop］shell was roughly about 0.05ml/g. It was observed by X-ray diffraction that the CaCO3 layers metamorphose to calcium hydroxide Ca(OH)2 above 450°C that may due to the hydrogen from conchiolin layers. It was also observed by FESEM that there are many nm-size holes on the surface of the seashells. These holes formation may due to hydrogen and etc. evolution from the conchiolin layers. Then after 800°C calcium oxide CaO was formed due to the Ca(OH)2 decomposition. It was also confirmed that surface area has increased up to about 11m2/g with increasing temperature using Specific Surface Area Analyzer (Shimazu Gemini VII 2390). After the heat treatment the hydrogen adsorption or chemical bind was observed in the seashells by using NMR analysis and oxidation-reduction potential (ORP) analysis.
Commercial Ca(OH)2 powder was obtained and similar experiment was done for comparison. The Ca(OH)2 powder was heated at the temperature range from 600 to 1300°C in Ar based 3% hydrogen gas flow. The hydrogen adsorption from the gas was confirmed using NMR analysis and ORP analysis. It showed adsorption of hydrogen at annealing temperature of around 800°C to 900°C. nm-size holes on the surface of Ca(OH)2 powder was also observed by FESEM. Hydrogen adsorption may be caused by this large surface area due to these fine holes.
(Keynote) Japan's Policy and Activity on Hydrogen Energy
Authors: Ohira Eiji 
Published: February 2020

This presentation will provide an overview of Japan’s hydrogen and fuel cell activities, focusing on the latest policy, market and NEDO’s research, development and demonstration programs. In June 2014, Japanese Ministry of Economy, Trade and Industry (METI) compiled the “Strategic Road Map for Hydrogen and Fuel Cells” toward the realization of a “hydrogen society.” This road map states how Japan would be able to make use of hydrogen, what are goals to be achieved in each step of production, transportation, storage and utilization of hydrogen, and what kind of collaborative efforts could be possible among industry, academia and government for achieving these goals.
Regarding market status, Japan has success to market introduction of hydrogen technology. Fuel cell micro combined heat and power system for household has been on market since 2009 and over 150,000 units are installed. Fuel cell vehicle was launched in December 2014 and around 70 hydrogen refueling stations have been operated now.
The New Energy and Industrial Technology Development Organization (NEDO) has been conducting comprehensive technology development and demonstrative research programs on hydrogen energy. The most recent result from NEDO’s program such as new materials for PEFC, analysis technology of morphology, electrochemical reaction and mass transfer in MEA, evaluation technology for long time fuel cell durability will be addressed. Following current topic, NEDO’s future challenge to develop hydrogen energy demand will be presented. NEDO just started R&D program to develop large scale n hydrogen supply chain with long-distance transportation of hydrogen and hydrogen gas turbine technology. NEDO is now also conducting Power to Gas which is a key technology to provide CO2 free hydrogen in the future.
Investigating the Effect of Chlorides on the Reaction Kinetics of a Copper Electrodeposition Process
Authors: Vyas Ritesh , Kubicsko Michael 
Published: February 2020

Over the past two decades, the replacement of aluminum interconnects with copper is one of the biggest advances in semi-conductor industry. As the wiring density continues to increase, so does the demand for tighter control on the electrolytic copper deposition process for these industries. Apart from organic additives and other trace metals, one of the crucial component in plating baths mixtures for manufacturing PCB boards and photovolotaic cells is the intermediate cuprous ion composition, which is formed during the copper dispropornation reaction:

2
Cu

+

(aq)

⇌ Cu(s) + Cu2+
(aq)

The cuprous ion is typically unstable in normal acidic solution and it disproportionates into metallic copper and cupric ions. In the presence of chlorides however, the disproportionation reaction equilibrium is shifted and the cuprous ions are stabilized. Cuprous ions are also required in order for the other additives (brightener, suppressor, leveler) used in the process to operate at maximum efficiencies. It is therefore important to know if the Cu2+
intermediate is truly formed and present during the a copper electrodeposition process.
In this work, we used Autolab RRDE system to identify mechanisms governing copper electrodeposition process and study the influence of chloride concentration on the generation of intermediates.