bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Multimodal Microprobe for Combined Multiple Neurochemical Sensing and Optical Stimulation
Authors: Wassum Kate M , Chiou Pei-Yu , Maidment Nigel T , Monbouquette Harold G 
Published: February 2020

Efforts to understand how neurons within networks interact to control behavior will be greatly facilitated by means with which to measure multiple neuroactive molecules in the brain simultaneously and in near-real time. We are developing an implantable microprobe capable of simultaneous rapid monitoring of three ubiquitous neurotransmitters/neuromodulators: dopamine (DA), glutamate (Glut), and acetylcholine. A detailed mathematical model is guiding electroenzymatic sensor optimization, and the use of a nanostructured Pt deposit has led to improved microsensors for choline and DA operated in constant potential amperometry mode. The creation of microsensor arrays for combined sensing of multiple neurochemicals is facilitated by the use of microcontact printing to deposit specific enzymes on selected microelectrode sites with fine control. Further, we are harnessing the power of optogenetics by incorporating an optical waveguide into our microprobes with microelectrode sensor arrays. This is achieved using an innovative silica-based microprobe design with embedded waveguides and a novel output grating coupler for directional illumination from the center of each neurochemical sensing site. The resultant microprobe enables local modulation of genetically isolated neuron terminals with measurement of transmitter release from those terminals. Our evaluation of probe performance in vivo has focused on the striatum and the basolateral amygdala (BLA). Optically evoked glutamate release has been observed successfully in the BLA of rats, but not in those genetically modified animals whose pre-synaptic activity is subjected to inhibition. Also, the improved DA sensors have enabled detection of electrical stimulation-evoked DA response in the rat dorsal striatum in the drug-naïve state. Further work to correlate multiple transmitter release events with behavioral actions will provide valuable information pertinent to the search for therapeutic interventions for multiple neurological and psychiatric disorders.
Three-Dimensional Freestanding Nanofiber Electrodes for Electric Double Layer and Pseudo-Capacitors
Authors: Kalra Vibha 
Published: February 2020

Fabrication of novel three-dimensional material architectures is essential for development of energy storage devices that allow high rate operation with sufficient energy capacity. In this talk, I will present our work on development of freestanding nanofiber-based electrodes using a simple electrospinning methodology for application in supercapacitors (EDLC/Pseudocapacitors)
We have developed porous carbon nanofibers (PCNF) that exhibit specific surface area of >1500 m2/g and multi-levels of pore sizes in the range of micro (< 2 nm), meso (< 50 nm) and macropores (> 50 nm). We studied these materials as freestanding electrodes in 1) electric double layer capacitors (EDLC) using liquid (aqueous and ionic liquid), as well as solid-state electrolytes and 2) as platforms for polyanilene (PANi) electrodeposition to develop hybrid supercapacitors that integrate electric double layer and pseudocapacitive energy storage. The unique combination of pores at different length scales allows us to achieve a battery-like energy density of up to 80 Wh/kg, while retaining high power and cycle life in EDLCs. In-operando infrared spectroelectrochemistry was conducted to understand the transport of ions through the carbon electrode pores and its effect on performance in ionic liquid-based EDLCs. In the hybrid supercapacitor devices, we demonstrated that the PCNF mats retain their EDLC behavior post PANi coating providing a 366 F g–1 gravimetric capacitance, 140 F cm–3 volumetric capacitance, and up to 2.3 F cm–2 areal capacitance at 100 mV s-1scan rate based on the weight, volume and area of the complete hybrid electrode – polyaniline coating and carbon substrate.
Relevant References: 1) Tran, C.; Lawrence, D.; Richey, F.W.; Dillard, C.; Elabd, Y.; Kalra, V. Electrochemical Performance of Device-ready Porous Carbon Nanofibers in Ionic Liquid Electrolyte-based Supercapacitors. Chemical Communications 2015, 51, 13760; 2) Richey, F.W., Tran, C., Kalra, V., Elabd, Y.A. Ionic Liquid Dynamics in Nanoporous Carbon Nanofibers in Supercapacitors Measured with in operando Infrared Spectroelectrochemistry, The Journal of Physical Chemistry C, 2014, 118, 21846; 3) Tran, C.; Singhal, R.; Lawrence, D.; Kalra, V. Polyaniline-coated Freestanding Porous Carbon Nanofibers as Efficient Hybrid Electrodes for Supercapacitors. Journal of Power Sources 2015, 293, 373.
Melamine-Based, N-Doped Carbon/Reduced Graphene Composite Foam for Li-Ion Batteries and Hybrid Supercapacitors
Authors: Tjandra Ricky , Liu Wenwen , Liu Yangshuai , Yan Ji , Lim Lucas , Yu Aiping 
Published: February 2020

Carbon foams, especially graphene foams, has recently received a lot of interest in the field of flexible energy storage due to their excellent electrochemical properties and flexibility. In this work, a compressible melamine-based carbon/reduced graphene oxide foam was synthesized using a simple one-step process. The nitrogen-rich melamine allows the final composite material to be rich in nitrogen, resulting in a higher conductivity and performance. The synergistic combination of nitrogen-doped carbon foam and reduced graphene oxide results in a compressible, free-standing, binder-free electrode (shown in Figure 1) with a capacity of 330 mAh g-1 at 0.1 A that can be used in both Lithium-ion Hybrid Supercapacitors (LIHSs) and Lithium-ion Batteries (LIBs). The composite electrode can also be used as a current collector for other active materials. As a proof of concept, a LIHS was fabricated using the composite foam as a free-standing electrode in both the cathode an anode. The resulting device has an energy density of 40 Wh kg-1 at 1 A that can be maintained for 800 charge and discharge cycles.
Figure 1 (a) 3D representation of the cMEGX synthesis procedure, (b) SEM image of neat melamine, (c) SEM image of a representative cMEGX sample, (d) optical image of cMEG800 showing its compressibility

Figure 1
Non Destructive Evaluation of Urethane-Epoxy Coating Systems Using the Scanning Kelvin Probe Technique
Authors: Borth David , Hansen Douglas C 
Published: February 2020

High performance aircraft are subjected to harsh environmental factors during operation including impacts with water and other particles, as well as high temperature and humidity. Rain erosion coatings (REC), made from polyurethane (PU), are used to protect the metal and other coatings from these damaging elements by absorbing the force of impacts and providing a barrier against corrosive substances. Over time these coatings break down and may fail in flight by delamination. Failure of a coating leads to unplanned downtime and expensive refinishing procedures. Coatings that are exposed to high temperature and humidity are particularly susceptible to degradation, leading to the assumption that the cause is hydrolysis or reversion. Hydrolysis affects the esters linkages whereas reversion targets the urethane bonds. These types of degradation lead to a breakdown of the polymer network structure and reduce both the tensile strength and melting point of the coating, increasing the likelihood of failure.
The dynamic nature of weather makes predicting when the PU REC will fail is extremely difficult when using traditional lifecycle estimates, since aircraft are exposed to different environmental conditions at different geographical locations or areas of operations. Currently, no method exists for accurately predicting when a particular aircrafts coating will fail. Therefore, there is a need for a reliable non-destructive method to detect the changes in the surface coating that indicate when it is close to failure or has begun to fail.
It is hypothesized that the Scanning Kelvin Probe (SKP) can be used to detect changes in the work function of the REC’s associated with degradation of the polymer structure. If successful, it will serve as the justification for developing a portable scanning unit that can be deployed by maintenance crews to determine when a coating needs to be reapplied. To test this, 4X6 inch 2024 aluminum alloy test panels were exposed in an autoclave to high heat and humidity (121˚C and 100% RH) for a variety of times to simulate the degradation process. They were then scanned with the SKP to characterize the degradation as a function of exposure time. Initial data shows that there is a change in work function with increasing exposure as well as localized areas of higher work function. Raman spectroscopic analysis indicates changes in coating polymer chemistry consistent with hydrolysis of the ester bonds. This data correlates with the changes in work function seen by the Kelvin probe, showing that the SKP can non-destructively detect polymer degradation.
Electrochemical and Corrosion Protection Performance of New Polymer Composite Coatings on Carbon Steel in Sulfuric Acid Medium
Authors: Branzoi Florina , Pahom Zoia 
Published: February 2020

In this study, galvanostatic electrodeposition mode was used for the synthesis of new composite (Ppy-AOT/PNEA and PNEA/ Ppy-AOT) coatings onto carbon steel of type OLC 45 for corrosion protection.
Monolayer poly (N- ethylaniline) (PNEA), polypyrrole (Ppy), dioctyl sulfosuccinate sodium (AOT) and bilayer PNEA/Ppy-AOT and Ppy-AOT/PNEA coatings have been electropolymerization onto carbon steel by galvanostatic synthesis techniques from aqueous solutions 0.1 M N ethylaniline, 0.1M pyrrole, 0.01 M dioctyl sulfosuccinate sodium (AOT) and 0.3 M oxalic acid. In order to include dioctyl sulfosuccinate ions as dopant in the polypyrrole, AOT was also added to the polymerization solution of polypyrrole.
The monolayer and bilayer polymers coatings were characterized electrochemically, spectroscopically and morphologically by cyclic voltammetry, Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) techniques.
Corros ion behaviour of PNEA-AOT/PPY coated carbon steel of type OLC 45 was investigated by potentiostatic and potentiodynamic polarization, open circuit potential measurements and electrochemical impedance spectroscopy (EIS) techniques in 0.5M and 1 M H2SO4solutions. The results of the corrosion tests showed that PNEA/PPY-AOT coatings ensure good corrosion protection of carbon steel in aggressive media. Bilayer coatings revealed better corrosion protection efficiencies than monolayer coatings. The new complex nanostructured composite obtained from this process is promising and might lead to industrial applications in the protection of the carbon steel substrates against corrosion.

Keywords: nanocomposite films, galvanostatic electrodeposition, corrosion protection, SEM, EIS, FT-IR
Effect of Residual Chlorine Concentration on Water Pipe Corrosion
Authors: Han Keum Seok , Park Ju-hyun , Park Young-bog , Kim Seong Jea , Kim Hyen Don , Choi Young-june , Choi In-cheol , Hong Seong Ho 
Published: February 2020

1. Introduction
Water pipe corrosion corrodes the iron by the oxidation reduction reaction, and the corrosion rate is accelerated by the oxidizing agent used as disinfectant in the tap water. The major oxidizing agent in tap water are ozone and chlorine. pH, alkalinity and residual chlorine concentration are factors of internal corrosion.
We are replacing the ductile cast iron pipe with inner coating and stainless steel pipe. However, it is still used in many cases, such as gray cast iron pipes and galvanized steel pipes without internal coatings in Korea.
Chlorine is a very strong oxidant for all metals and organics, and the reaction between chlorine and iron is as follows.
HOCl + 2Fe2+ + 5H2O → 2Fe(OH)3↓ + Cl- + 5H+

Recently, as the problem with sinkholes has arisen on the a buried road as water pipes, sewage pipes, etc, interest in corrosion has been growing.
The purpose of this study is to evaluate the effect of residual chlorine on the corrosion factor by analyzing the water quality and to evaluate the necessity of the proper residual chlorine on in the water purification plant.
2. Experimental Method
In order to evaluate the corrosion of residual chlorine concentration of tap water, we were carried out Tafel experiment and water quality analysis. The corrosion rate was measured by a Tafel experiment using an electrochemical corrosion measurement system (PAR VMP-3). For tap water in Seoul, corrosion evaluation was performed according to alkalinity and hardness, residual chlorine concentraion.
3. Summary of results
The tap water quality of Seoul was as follows that residual chlorine is 0.4 mg/L, and alkalinity is 50 mg/L as CaCO3, with a pH of 7.3. The results of experiments on the rate of corrosion of Carbon Steel specimens to residual chlorine in seoul tap water, can be seen in Fig. 1.
As a result of the Tafel experiment according to the initial residual chlorine concentration under the same conditions (same LI index), The corrosion rate was 0.01 mmpy at 0 mg/L of residual chlorine and 0.074mmpy at 0.8mg/L of residual chlorine, corrosion rate for residual chlorine in carbon steel specimens was more than 7 times. It was confirmed that the higher the concentration of residual chlorine, the faster the corrosion rate was increased.
The corrosivity of tap water in Korea is evaluated by the LI index, but residual chlorine has a large effect on corrosion, so it is required to add residual chlorine for the tap water corrosion evaluation.
It is reducing the concentration of residual chlorine for reduce the chlorine odor of tap water in the distribution water system in Korea. But, residual chlorine guideline for corrosion reduction is necessary in Korea.

Figure 1
Recent Developments in Mild Steel Corrosion Rate Predictive Models in Sweet Environments
Authors: Kahyarian Aria , Nesic Srdjan 
Published: February 2020

An accurate and reliable corrosion rate prediction is an essential parameter in design, material selection, and mitigation strategies for oil and gas transmission pipelines. While underestimating the corrosion rates may result in health, safety, environmental concerns and financial loss due to maintenance costs and production interruption, overestimation of this parameter may result in significant unnecessary costs for pipeline construction and maintenance. Such concerns have been a strong driving force for developing a better understanding of the corrosion phenomena and advancements in the corrosion rate predictive tools.
The corrosion rate predictive models developed to date can be classified depending on the mathematical description of the fundamental thermodynamics and kinetic processes, underlying the corrosion phenomena. That includes empirical models, semi-empirical models, elementary mechanistic models, and comprehensive mechanistic models. The advantages and deficiencies of each group of models was discussed in detail in an earlier review [1]. The present study is focused on improving the comprehensive mechanistic models.
Considering the importance of the chemical composition of the solution, the water speciation calculations were updated with more recent literature data. The non-ideal behavior of the gas phase (CO2) in terms of fugacity coefficient and the liquid phase in terms of activity coefficients were incorporated into the model. It was shown that assuming an ideal behavior would result in significant error in chemical speciation at pCO2>10 bar. A more simple charge transfer rate calculations were proposed to replace the Tafel equation commonly used in the literature. It is shown that not only these expressions are mathematically more simple, but they are also more theoretically consistent with the conditions typical in corroding systems. The effect of organic acids (acetic acid in particular) is included in the CO2 corrosion model considering the recent mechanistic findings [2].
The existing comprehensive mathematical models usually assume an infinitely diluted solution in calculations. This matter is also disused in terms of the effect of non-ideal solutions in mass transfer and charge transfer rates. The present model was developed based on moderately diluted solution theory to partially accommodate for the non-ideal behavior but maintain a reasonable computation time. Furthermore, the precipitation and growth of an iron carbonate corrosion product layer is included in the model to account for the effect of this protective layer on the mass transfer and charge transfer rates.

References

[1] A. Kahyarian, M. Singer, S. Nesic, Modeling of Uniform CO2 Corrosion of Mild Steel in Gas Transportation Systems: a Review, J. Nat. Gas Sci. Eng. 29 (2016) 530–549. doi:10.1016/j.jngse.2015.12.052.
[2] A. Kahyarian, B. Brown, S. Nesic, Mechanism of Cathodic Reactions in Acetic Acid Corrosion of Iron and Mild Steel, Corrosion. 72 (2016) 1539–1546. doi:http://dx.doi.org/10.5006/2177.
A Study of NiTi Alloy Mechanical and Corrosion Behavior Subjected to Mechanical and Cyclic Thermal Loading in Corrosive Environment
Authors: Mohajeri Mahdi , Castaneda Homero , Lagoudas Dimitris 
Published: February 2020

The corrosion behavior of a nickel titanium alloy (NiTi) have been investigated. The NiTi alloy is
subjected to cyclic thermal loading in corrosive environments (3.5 wt% NaCl and Ringer
solution).
Thermogravimetric measurement versus temperature is perfumed to obtain forward and
reverse martensitic transformation temperatures.
Electrochemical Avesta cell is used to study corrosion behavior of NiTi alloy under thermal
cycling in absence of mechanical loading. Electrochemical Impedance Spectroscopy and cyclic
voltammetry measurements are used to study corrosion behavior at different temperatures
and phases.
The change in corrosion rate during phase transformations are being investigated. An
equivalent circuit model is used to calculate the electrochemical parameters from EIS
measurements for forward and reverse martensitic transformations. The results shows the
breakdown of passive oxide film on the surface with martensitic transformation. This
breakdown would be an origin for fatigue crack initiation and an explanation for fatigue lifetime
reduction of NiTi in corrosive environments.
Galvanic Corrosion of AA7075-T6 Caused By Doped Titanium Oxides in a Controlled Atmospheric Environment
Authors: Policastro Steve , Anderson Rachel , Horton Derek J. , Hangarter Carlos , Keith John A. , Groenenboom Mitchell C. 
Published: February 2020

Reduction reactions, such as oxygen reduction, hydrogen evolution, nitrate reduction, and sulfate reduction, are of interest in atmospheric corrosion because they are more positive than many structural airframe alloy oxidation reactions and can therefore drive material breakdown. The rate controlling reduction reaction is the one capable of supporting the largest corrosion rate at a given potential. In the case of heterogeneous corrosion, in which the anodic and cathodic sites are spatially distinct and stable, as is found in a galvanic couple; the ability of the noble metal to support a reduction reaction strongly influences the corrosion of the active metal.
For aircraft alloys having received conversion coatings and topcoats to control self-corrosion due to precipitate phases, high-strength fasteners made of stainless steel or titanium alloys are the most obvious point of attack for galvanic corrosion. In atmospheric electrolytes, droplet chloride concentrations can exceed 4M, and the oxygen reduction reaction (ORR) is frequently the dominant reduction reaction driving corrosion. Novel binary titanium alloys that had been developed using density functional theory and Monte Carlo simulations that predicted oxygen reduction reaction (ORR) rates on the metal oxides, were coupled to structural aluminum alloy (AA7075-T6) panels and exposed to a simulated tropical rainforest environment for 30 days in order to compare predicted galvanic corrosion rates with actual galvanic corrosion in an environment in which Cl-ions were applied in a controlled manner.

Acknowledgment

This work was sponsored by the Office of Naval Research, ONR, under grant/contract number N0001415WX00948; the views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Office of Naval Research, the U.S. Navy or the U.S. government.
Figure 1. Galvanic corrosion test panels exposed to a simulated tropical rainforest environment with controlled chloride dosing.

Figure 1
Dissolution and the Consequent Surface Morphology of Pt-Cu Binary Alloys Under Potential Cycling
Authors: Ooi Azusa , Tada Eiji , Nishikata Atsushi 
Published: February 2020

Polymer electrolyte fuel cell (PEFC) is regarded as clean energy conversion system, however its high cost prohibits the progress of PEFC. Thus, a reduction in the amount of Pt used as cathode catalyst is required. In order to overcome this problem, Pt transition-metal (Pt-M) alloy catalysts have been developed instead of Pt catalysts, however a deterioration of Pt-M alloy catalysts is concerned because both Pt and M are dissolved from Pt-M alloy catalysts under PEFC operating conditions. In this study, potential cycling tests and inductively coupled plasma mass spectroscopy (ICP-MS), field emission-scanning electron microscopy (FE-SEM), and field emission auger electron spectroscopy (FE-AES) were combined, and dissolution behavior of Pt-Cu alloys has been investigated under potential cycling by using these techniques.
Pt50-Cu50 (Pt-50 at% Cu) and Pt25-Cu75 were fabricated by arc-melting under an Ar atmosphere. These alloys were subjected to potential cycling tests at 298 K in 0.5 M H2SO4 solution with a two-compartment stationary cell. A double junction silver / silver-chloride electrode was used as reference electrode, and Au coil was used as the counter electrode. A total of 1,000 cycles of potential cycling tests were employed between 0.05 V and 1.4 V vs. SHE at 100 mV s-1. Tests was interrupted every 100 cycles, and the test solution was sampled for quantitative ICP-MS analysis of both Pt and Cu ions dissolved in it. In addition, surface structure and depth profile after potential cycling tests were evaluated by FE-SEM and FE-AES, respectively.
FE-AES depth profiles before and after 100 cycle potential cycling confirmed that Pt-enriched layer formed on Pt25-Cu75 surface after potential cycling. Moreover, the amount of dissolved Pt and Cu ions during 1st sequential order of 100-cycles-potential cycling were 1 monolayer (ML) and 2370 ML, respectively. Hence, Pt-enriched layer formed by the large amount of Cu selectively dissolved from Pt25-Cu75. FE-SEM image of Pt25-Cu75 after 100 cycle potential cycling showed numerous pits (d
pit = 2 – 5 nm) formed on its surface, and the large amount of Cu dissolution occurs from 2nd to 10th sequential order of 100-cycles-potential cycling. Thus, selective dissolution of Cu seems not to be suppressed in the latter cycles because Cu dissolution continuously occurs through the pits. On the other hand, FE-SEM image of Pt50-Cu50 after 100 cycle potential cycling was extremely flat. Accordingly, dense Pt-enriched layer formed on its surface, and it suppressed further Cu dissolution from the alloy.
The authors acknowledge Ookayama Materials Analysis Division, Tokyo Institute of Technology, for assistance with the ICP-MS analysis.