bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monitoring Gas Sensors at Work: Operando Raman-FTIR Study of Ethanol Detection By Indium Oxide
Authors: Hess Christian 
Published: February 2020

Metal-oxide semiconductors such as In2O3 have been used widely as gas sensing materials because of their high sensitivity to target gases and their simple fabrication. Their operation is based on changes of the materials electrical conductivity caused by the adsorption of gas molecules on the semiconductors surface. Despite progress in the field, a detailed mechanistic understanding of the gas sensing process is still missing. The knowledge-based development of better gas sensors crucially depends on the development of experimental approaches allowing for a correlation of the sensor response with spectroscopic information obtained under working conditions of the gas sensor (operando approach). In this contribution we demonstrate the potential of this approach using a new operando Raman-FTIR experiment enabling the simultaneous measurement of the sensor response, adsorbed species (Raman), changes of the metal-oxide material (Raman) and gas-phase composition (FTIR).[1]
Our results for ethanol gas sensing show a correlation between the sensor signal, the nature of the adsorbates, the indium oxide oxidation state and the surface hydroxyl group intensity depending on gas environment and temperature (see Fig. 1) [1]. For example at 190°C, in the presence of ethanol (250 ppm, EtOH/N2), the hydroxyl band at 3659 cm-1 disappears and that at 3643 cm-1 band becomes weaker due to their reaction with ethanol forming acetate groups (937 cm-1, 2937 cm-1). In the course of the redox reaction indium oxide is reduced as characterized by the appearance of bands at 325 cm-1 and 407 cm-1. These changes are accompanied by a strong decrease in sensor resistance. Thus our results show that ethanol is oxidized to adsorbed acetate by indium oxide releasing electrons to the conduction band consequently decreasing the resistance.
Summarizing, our study demonstrates that detailed spectroscopic analysis under working conditions of the gas sensor is essential to unravel its mode of operation.
References:
[1] S. Sänze, A. Gurlo, C. Hess, Angew. Chem. Int. Ed. 2013, 52, 1.
The Potential of Sensors and Biosensors for Integrated Process Control in Real-Time. Can They Survive the Environment?
Authors: VAN Staden Jacobus Frederick 
Published: February 2020

The industry of tomorrow places a heavy demand on more efficient processes that performs in a more fluent cost-saving and sustainable way throughout the whole process production system. These industries need improvements in process monitoring and measurement that is the key for delivering better process control and therefore more sustainable processes. Innovations in process measurement are therefore needed to relate more closely to the full stream process environment to deliver better higher final quality products by allowing better process control and hence substantial cost reduction and a friendlier environment.
This will need a complete new approach for the different scenarios regarding the innovation, development, design, behaviour, implementation and application of sensor and biosensors. These type of measuring devices and probes should functioned in temperatures on a continuous basis for extended periods ranging from temperatures around
1000 ºC to room temperature and even below and from high pressures to normal pressures depending on the process production system. This talk will look and outlined different types of sensor and biosensor devices currently available and the potential to survive in the environment of integrated process control in real-time.
Acknowledgements
The present work was supported by the Romanian National Programme
PN II, Ideas, Contract Nr. 100/27.10.2011.
Peculiarities of Electroless Copper Deposition Using Environmentally-Friendly Natural Polyhydroxylic Compounds As Cu(II) Ligands
Authors: Norkus Eugenijus , Prusinskas Kestutis , Stalnioniene Irena , Tamasauskaite-Tamasiunaite Loreta 
Published: February 2020

Cu(II) ligands are important components of common formaldehyde-containing alkaline electroless copper plating baths:
Cu(II)-Ligand + 2CH2O(hydrated) + 4OH- → Cu + 2HCOO- + H2 + 2H2O + Ligand (1)
From one hand, the ligands used should form Cu(II) complexes stable enough to prevent Cu(OH)2 formation, since the solubility product of Cu(OH)2 is of the order 10-18 and the concentration of “free” (uncomplexed) Cu(II) ions in the pH range 11–14 cannot exceed 10-12–10-18 M, respectively. On the other hand, it is worth to note that kinetics of copper deposition as well as the properties of copper deposits (compactness, exterior, morphology and crystal structure) in high extent depend on the nature of ligands used for Cu(II) binding into complexes in electroless copper plating solutions.
The aim of the study presented herein was comparison of the parameters of process of electroless copper plating – mainly plating rate and nanoscale surface roughness of the copper deposits obtained, – using different polyhydroxylic ligands under the similar conditions.
The ligands considered were glycerol, xylitol, D-mannitol, D-sorbitol and saccharose.

Acknowledgement

The work was carried out within the Project VP1-3.1 ŠMM-08-K-01-009 that is partly supported by the National Programme “An Improvement of the Skills of Researchers” launched by the Lithuanian Ministry of Education and Science.
Structure and Phase Distribution of the Electrophortically Deposited Hydroxyapatite and Cerium Oxide
Authors: Saraf Shashank , Gupta Ankur , Seal Sudipta , Tsurtsumia Olga 
Published: February 2020

HydroxyApatite (HA) is known as a typical representative of the biologically active ceramics the coatings if which on the implant materials is considered as one of the ways of achieving the natural and accelerated bonding to the living tissues. Ceria (CeO2) is an anti -oxidative and -inflammatory substance material for the application in bio-medical fields the interest towards which is increasing drastically. The attempt to apply those two ceramic nano powders together has never been done before. In the given work, the electrophoretic deposition of HA and CeO2(separately as well as from the binary solution) was conducted on metallic substrate materials having different conductive properties. As specimens the potential implant alloy of Fe-Cr-Al-RE and a pure Ni mesh were taken. That allowed us to get the data related to the deposition on the flat and high surface area having porous materials as well as that of the ones having different electrical properties: Ni mesh showing outstanding electrical conductivity and thermally pretreated Fe-Cr-Al-RE alloy that formed corrosion protective passivation surface layer of alumina being known as insulating ceramics.
Various deposition parameters were applied and the most appropriate one was selected for our further research purposes. Amongst many different coating deposition techniques available the electrophoretic one is characterized by the simplicity, low price and of course with the coating parameters comparable with the ones obtained by the other commercial rather expensive techniques.
The Figure 1 shows electrophoretically successfully deposited top layer of HA nanoparticles. The microstructure, phase composition and their distribution within the deposited ceramic layers of HA, CeO2 and HA+CeO2were carefully studied using scanning electron microscopy, XRD and EDX methods. Some calculations on the to be deposited particles potentials and their deposition parameters were done.
The present work has revealed that electrophoretic deposition of the HA, CeO2 or HA+CeO2 nano powder coatings has a strong potential to be widely applied for the bio-medical (and possibly in other) fields.
Step-Voltage Testing of Ni-Cd Batteries
Authors: Lipkin Mikhail Semenovich , Lipkin Semen M. , Sedov Andrey Vladimirovich , Onyshko Dmitry Anatolievich 
Published: February 2020

State of charge diagnostics is very important problem for high power batteries, charging by constant voltage during long time. For many types of secondary cells, based on intercalation processes, a relation between capacity and current response on potential step can be obtain. This relation is direct proportional only in ideal case, but for real batteries a lot of different causes transformed this relation to more complex form. In this situation neural network models give some advantages.
Proposed principle of diagnostics is based on applying series of steps of voltage with information about battery’s capacity appears in values of corresponding current steps. Three-step voltage was used therefore three values of current were available for calculating the value of capacity (fig. 1).
In this paper 24 batteries with capacities varying from 0.5 A/h to 1.2 A/h were used, so the training set consisted of 24 three dimensional vectors of current values. Principal components analysis [1] has shown that capacity information (data variance in training set) is approximately evenly distributed over all three current values, therefore all of them can be directly used as an input for calculating value of battery’s capacity.
For such calculation feed forward neural network (ANN) with one hidden layer containing three neurons was used. Considering that speaking of battery’s capacity lower prediction is much less critical than higher one results of ANN work can be shown on the following histogram (fig. 2).
Thus, multiple voltage steps technique is multiparameter diagnostic, which provides determination on-line state of charge of secondary batteries. It is especially important for high power modules in the condition of complex history.

Jolliffe, I. T., Principal Component Analysis, 1986, Springer-Verlag, p 487.
The Electrochemical Capacitive Laber-Free Detection of DNA Modification and Hybridization Process Using Interdigitated Gold Microelectrodes
Authors: Solis-Marcano Nadja Enid , Pinto Brismar , Lopez-Nieves Marjorie , Cabrera Carlos R , Diaz-Cartagena Diana C 
Published: February 2020

Detection of specific DNA sequences in biological samples has been playing a fundamental role in genetic diagnostic for rapid identification of diseases. Traditionally DNA hybridization detection is performed by using a redox or fluorescent probe that can detect the hybridization process. These techniques are expensive and time consuming. Considerable effort has been made for more than a decade to miniaturize and integrate the whole process in a single disposable chip. Here, we propose a non-faradaic, label-free, electrochemical method based on capacitance measurement to sense DNA surface modification and hybridization.
For this, we created custom-made Interdigitated-Array gold Microelectrodes using photolithography technique. Silver electroplating was used to make a stable silver chloride quasi-reference. Self Assembled Monolayers of single stranded B. Anthracis hairpin were made and exposed to complementary, non-complementary and 3 bases mismatch to study the hybridization and/or non-hybridization processes using Electrochemical Impedance Spectroscopy measurements.
Hot Corrosion Behaviors of Cr2alc, Cr3C2, and Al4C3 Thin Film Coatings on Ni-201
Authors: Aw LikMing , Amendola Roberta , Gannon Paul E. 
Published: February 2020

Hot corrosion, also known as deposit-induced accelerated oxidation, is an insidious challenge for hardware within high-temperature systems, such as gas turbines in combined cycle power plants and aircraft engines. This hardware, generally consisting of nickel based super-alloys, often requires protective surface coatings to satisfy the requirements of both superior mechanical properties and high-temperature corrosion resistance.
Mn+1AXn (abbreviated as MAX, where M is an early transition metal, A is an IIIA- or IVA-group element, and X is C or N) phases have received increasing attention because of their unique combination of properties including excellent thermal shock resistance and damage tolerance. Among them, Cr2AlC has attracted considerable interest because of its excellent high-temperature oxidation and hot corrosion resistance. The main objective of this study is to determine the effectiveness of Cr2AlC, Cr3C2 and Al4C3 thin film coatings for the hot corrosion protection of Ni-201. Different thin film coatings were deposited via magnetron sputtering physical vapor deposition (PVD) before being exposed to air and 2 ppm SO2 at both 700°C and 900°C for up to 200 hours to simulate hot corrosion conditions.
Phase compositions of each coating before and after exposure were assessed using x-ray diffraction (XRD) and their corresponding morphologies (surfaces and cross sections) analyzed with a scanning electron microscope (SEM) equipped with an energy dispersive x-ray spectroscopy (EDS) system.
The coated specimens exhibited much better oxidation behavior as compared to the bare material. A continuous oxide scale formed on the coating surface during the initial oxidation stages. The oxide scale and coating itself acted as diffusion barriers blocking the further ingress of oxygen and protected the substrate alloy from oxidation. The oxidation mechanisms of the bare alloy and the coated specimens were proposed and compared based on the experimental results. The coating degradation can be attributed to the Al and Cr consumption by surface oxidation and inter-diffusion between the coating and the substrate. Results and interpretations will be presented and discussed in context of improving mechanistic understanding of hot corrosion behaviors of MAX phase materials.
Lithium-Air Cells Assembled with Nitrogen and Sulfur Co-Doped Graphene Electrode
Authors: Kim Jae-Hong , G Kannan Aravindaraj , Kim Dong-Won 
Published: February 2020

Rechargeable lithium-ion batteries are widely used as the power source for portable electronic devices, electric vehicles and energy storage systems. However, their energy density cannot fulfill the requirements of applications for electric vehicles. In this respect, lithium-air batteries have been in focus due to their higher energy density than the currently commercialized Li-ion batteries. Recently, diverse approaches on air electrode have been reported to enhance the cycling performance of Li-air batteries, such as nanostructured metal oxide, superfine platinum particles, bi-functional catalyst loaded onto carbon and metal free graphene nanosheets [1]. Graphene has been receiving a lot of attention for energy storage applications because of its high electronic conductivity, high surface area, chemical stability and good mechanical strength. Furthermore, chemical doping in graphene materials showed a considerable increase in electrochemical activity relative to pristine carbon materials [2]. In this study, we synthesized nitrogen and sulfur co-doped graphene to improve the electrochemical performance of lithium-air cell. The cycling performance of lithium-air cells assembled with N,S-doped graphene cathode was investigated and compared to that of a cell with carbon-based air electrode. The detailed investigation was carried out using electrochemical impedance spectroscopy, FE-SEM, HR-TEM, RDE and XPS analyses.

References

1. B.Sun, B.Wang, D.Su, L.Xiao, H.Ahn, G.Wang, Carbon, 50,727 (2012).
2. A.L.M.Reddy, A.Srivastava, S.R.Gowda, H.Gullapalli, M.Dubey, ACS Nano, 11, 6337 (2010).
Optimization of Basic Parameters of New Sodium Electrolytes Based on Tailored Anions
Authors: Bitner Anna , Nolis Gene , DeWever Natacha , Niedzicki Leszek , Kalita Michal Jan , Trzeciak Tomasz , Poterala Marcin , Gajewska Agnieszka , Wieczorek Wladyslaw , Marcinek Marek 
Published: February 2020

Secondary battery technology is currently based on Li-ion technology. Assuming substantial development of electrical vehicles and/or different portable devices, the lithium sources might be not sufficient to fulfill total market demands. Strategically, it is a suitable moment to research alternatives to lithium-based energy storage technologies. A natural candidate for the replacement of lithium is sodium. Standard potential of the Na/Na+ (-2.71 V) is slightly lower than the potential of Li/Li+(-3.05 V). At the same time, sodium is both the most abundant alkali metal on Earth and cheaper than lithium.
The first sodium battery, Na (Hg)-C cell, was built in 1870. Later, sodium batteries which were built in 1960s (Na-S) and 1980s (Na-NiCl2). All of these technologies exhibit low energy density. The Na-NaSICON-S system, built in early 2000s, exhibits a much higher energy density[1]. However, a major problem of this battery, which remains unsolved up to now, is its high working temperature. Therefore, the current challenge in sodium battery research is to reduce the operating temperature from 270-350°C to room temperature. In order to reach this goal, the ionic conductivity of the electrolyte must be optimized.
New sodium salts with heteroaromatic anions, used in electrolytic media are being investigated because they are environmentally benign, facile to synthesize and are not expensive to produce at an industrial level. In addition, they show promising ionic conductivities in liquid and solid electrolyte media and possess good electrochemical stability at room temperature. Moreover, these salts have been preliminary characterized in the half cells; where the anode specifically was fabricated using Microwave Plasma Chemical Vapor Deposition from germanium and antimony precursors[2] and cathodes were obtained from independent laboratory.

References:

[1] P.V. Wright, British Polym. J. 7 (1975) 319
[2] M. Marcinek, L. Hardwick, G. Żukowska, R. Kostecki Microwave Plasma Chemical Vapor Deposition of Graphitic Carbon Thin Films, Carbon 48 (5) 2010 1552-1557
Polysulfide Rejection Layer for High Performance Lithium Sulfur Batteries
Authors: Kim Hee-tak , Park Jung-Ki , Song Jongchan , Noh Hyungjun , Lee Lee Hongkyung , Lee Dong Jin 
Published: February 2020

Polysulfide (PS) shuttle has been an impediment to the development of lithium-sulfur batteries with high capacity and cycling stability. Previous efforts to mitigate PS shuttle were mainly focused on 1) the suppression of diffusion of dissolved PS out of the cathode by geometrically trapping PS in porous carbons or adsorbing PS on oxides and conducting polymers and 2) protection of the Li anode from reaction with PS by forming a passivation layer on the Li metal surface or a hybrid anode structure.
Here, we report a new strategy to remedy the problem using a polymeric polysulfide rejection layer via in situ or ex situ routes. The key concept of this strategy is to form a thin layer which selectively rejects PS anions but permeates lithium ion, mimicking cell membrane. The in situ formed PS rejection layer, which was developed on the sulfur cathode surface from an electrolyte additive during the first discharge, effectively prevented PS shuttle and consequently enhanced discharge capacity and cycling stability owing to an electrochemical equilibrium between the PS-containing cathode electrolyte and the PS rejection layer. In detail, the discharge capacity at the third cycle was 995 mAh g-1 for the cell with the in situ PS rejection layer and 829 mAh g-1 for the reference cell. At the 200th cycle, the PS rejection layer cell delivered a reversible 787 mAh g-1. In contrast, the discharge capacity of the reference cell dropped to 575 mAh g-1after 200 cycles, which was 73% of the discharge capacity of the cell with the PS rejection layer.
Using the ex situ formed layer, which exhibited a similar polysulfide rejection behavior as the in situ layer did, the influence of chemical structure of the layer and battery architecture including the layer were investigated. Battery performances were highly dependent on the chemical nature and physical configuration of the layer. In particular, the layer inserted in the interface of cathode and bulk electrolyte phase improved reversible capacity, whereas, that in the interface of anode and bulk electrolyte phase increased cycling efficiency.
The Effect of Carbon Support Structure on Ionomer Distributions in PEM Fuel Cell Catalyst Layers
Authors: More Karren L. , Cullen David A , Reeves Kimberly Shawn 
Published: February 2020

Ionomer thin films form the proton-conducting path within the catalyst layers (CL) of polymer electrolyte membrane fuel cells (PEMFCs) and the web-like ionomer network provides support for the porous CL structure. The recast ionomer is assumed to be relatively uniform in thickness, structure, and chemistry across the entire CL thickness, but there are numerous factors that can significantly influence the homogeneity and dispersion of the ionomer as well as its stability during electrochemical aging. These factors include (1) the type of carbon support material used, including the extent of graphitization (or lack thereof) and the presence of surface oxide functional groups, (2) the loading, dispersion, and size/shape of Pt-based electrocatalysts, and (3) the CL pore structure. Recently, extensive studies have been conducted to identify the optimum conditions for examining ionomer thin films using electron microscopy and spectroscopy techniques1 and molecular dynamics (MD) simulations have been performed to identify the structure and adhesion of ionomer thin films on carbon and Pt surfaces.2 The current work will expand on this microscopy research to apply specific microscopy methods, including high-resolution imaging and spectroscopy coupled with electron tomography, to identify the nature of ionomer film dispersions within CLs prepared with different carbon supports having varying degrees of graphitization (high surface area carbon, Vulcan, and fully graphitized low surface area carbon) and Pt loadings. Additionally, changes to these ionomer films within the different CLs during accelerated stress testing (AST), specifically the AST for carbon corrosion (1.2V hold for 100-400 hours), will be analyzed and compared in terms of changes to the ionomer distributions on the changing carbon surfaces. Microscopy observations will be coupled with MD simulations to better understand the correlations between ionomer dispersion and structure and the materials comprising the CLs.
References:
1. D.A. Cullen, et al., “Imaging and Microanalysis of Thin Ionomer Layers by Scanning Transmission Electron Microscopy,” in preparation.
2. Q. He, et al., “Structure of the Ionomer Film in Catalyst Layers of Proton Exchange Membrane Fuel Cells,” Journal of Physical Chemistry C
117 25305-25316 (2013).
Research sponsored by (1) the Fuel Cell Technologies Office, Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy and (2) through a user proposal at ORNL’s Center for Nanophase Materials Sciences, which is sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy.