bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Single Cell Detection Using Magnetic Zigzag Nanowire Biosensor
Authors: Huang Hao-Ting , Wei Zung-Hang 
Published: February 2020

Among various types of biosensors, magnetoresistance-based biosensors possess several advantages including high sensitivity and being less interfered by the environment, and are therefore suitable for sensitive biodetection [1-4]. Besides, the magnetic is not shielded by chemical compounds, microstructures, or another biomaterials, so the signals detected by the magnetoresistance-based biosensors are not influenced by the surrounding objects. In this report we present wave Permalloy (Ni81Fe19) nanowires with various line widths as a biomolecular sensing device. In this design, the magnetic poles on the apexes and valleys of the wave Permalloy nanowires can actively attract the magnetic beads immobilized biomolecular onto the nanowires for detection.
Permalloy nanowires with line widths 300 and 500 nm deposited onto wave silicon grooves were designed as biosensing devices of nano magnetic beads, which modified by biomolecule. Figure 1 shows the SEM image of the wave ferromagnetic nanowires. We applied a magnetic field along x axis, and measured the magnetoresistance curves of the nanowires before and after the attachment of magnetic beads by four-probe method. The stray field generated by the magnetized beads are against the magnetic moments of the wave sheet surfaced film, therefore making it harder for the switching process to occur. It was observed that the sensitivity 43.29% in switching field variation after magnetic beads were attached can be obtained when the field was applied perpendicular to the plane of the 300 nm wide nanowire. The sensitivity 45.78% in magnetoresistance variation occurred in the 500 nm wide nanowire for the same field direction.
Further work, we will focus on different wire width (150, 300, 500, and 800 nm) before and after attaching nano magnetic beads on the nanowires, when magnetic fields were applied in various directions,x, y, and z (out-of-plan) axes.
[1] B. Ilic, D. Czaplewski, H. G. Craighead, P. Neuzil, C. Campagnolo, and C. Batt, Appl. Phys. Lett. 77, 450 (2000).
[2] H. K. Kim, J. S. Hwang, S. W. Hwang, and D. Ahn, Nanotechnology 21, 465501 (2010).
[3] S. Tombelli, M. Minunni, and M. Mascini, Methods 37, 48 (2005).
[4] P. Kauffmann, A. Ith, D. O’Brien, V. Gaude, F. Boué, S. Combe, F. Bruckert, B. Schaack, N. M. Dempsey, V. Haguet, and G. Reyne, Lab Chip 11, 3153 (2011).

Figure 1
Sustainable Innovations Electrochemical Technologies
Authors: Molter Trent M. 
Published: February 2020

We live in a world that demands innovation. There is no way forward without a different way of thinking and doing. Companies cannot sustain themselves, and the world cannot sustain us by conducting business as usual. It’s time to become smarter about the way we do things. Sustainable Innovations has developed a low-cost, fluids-flexible, scalable electrochemical platform based on the proton pumping capability of cation exchange membranes to meet near-term and emerging market needs. Sustainable Innovations’ products serve global, high-value applications including: Hydrogen for industrial use, energy, and vehicle fueling; energy storage (regenerative fuel cells); and recycling CO2 into high-value fuels and chemicals. This paper discusses the key features of the common electrochemical platform as well as important differences in the hardware design elements and electrochemistry associated with each of these specific products that leads to important cost and performance benefits for end-users.
Doped and Decorated Graphene Foam Electrocatalysts
Authors: Lyth Stephen Matthew , Liu Jianfeng , Mufundirwa Albert , Sasaki Kazunari , Daio Takeshi 
Published: February 2020

Graphene is an ideal material for electrochemical applications due to high electrical conductivity, large surface area, and stability over a wide electrochemical potential window. However graphene is expensive; it is difficult to control porosity (and thereby mass diffusion); and it is difficult to dope effectively. Simple carbon foams with large micron-scale pores, very thin walls, and very large surface area (e.g. 2500 m2/g) can be synthesized at low cost by thermal decomposition of sodium ethoxide.[1,2]
Crucially, by decomposing nitrogen-containing alkoxides, nitrogen-doped graphene powders are made.[3] These do not contain transition metal contamination, as is the case with carbon nanotubes and carbon black. Therefore they can be used to probe the fundamental oxygen reduction reaction (ORR) activity of nitrogen-doped carbon in acid – a relatively under-represented research topic, plagued by contamination issues.[4,5] We record surprisingly high mass activity and onset potential for the ORR, with high electron transfer number (3.6). The negligible metal content was confirmed by ICP-AES. This work shows that 4-electron ORR is possible even in the absence of transition metals, most likely at (or adjacent to) tertiary nitrogen sites.[6]
The activity in alkaline medium is also of interest, due to the development of new alkaline ion exchange membranes and the faster ORR kinetics. The nitrogen-doped graphene foams presented here display negligible degradation in cyclic voltammograms over 60,000 load potential cycles, demonstrating the applicability of such metal-free non-precious electrocatalysts in application that require long lifetimes.[7]
[1] S. M. Lyth, H. Shao, J. Liu, K. Sasaki, Int. J. Hydrogen Energy, 2014, 39, 376
[2] J. Liu, D. Takeshi, K. Sasaki, S. M. Lyth, J. Electrochem. Soc. 2014, 161, F838
[3] S. M. Lyth, Y. Nabae, N. M. Islam, et al., eJournal of Surface Science and Technology, 2012, 10, 29-32.
[4] S. M. Lyth, Y. Nabae, N. M. Islam, S. Kuroki, M. Kakimoto, S. Miyata, J. Nanosci. Nanotechnol. 2012, 12, 4887
[5] S. M. Lyth, Y. Nabae, N. M. Islam, S. Kuroki, M. Kakimoto, S. Miyata, J. Electrochem. Soc. 2011, 158, B194
[6] J. Liu, D. Takeshi, D. Orejon, K. Sasaki, S. M. Lyth, J. Electrochem. Soc. 2014, 161, F544
[7] J. Liu, K. Sasaki, S. M. Lyth, ECS Trans. 2014, 64, 1161

Figure 1
3d and 4f Ions in Solids: Description and Understanding of Optical Properties
Authors: Brik Mikhail G. , Srivastava Alok M , Camardello Sam Jospeh 
Published: February 2020

An overview of recent results on modeling of properties of optical materials doped with transition metal and rare earth ions is given. Studies of various groups of materials – pyrochlores, perovskites, garnets, spinels – are presented. Applications of several different approaches (e.g. crystal field theory, DFT-based computational techniques, configurational coordinate model etc) are discussed in details. Special attention is given to the positioning of impurity ions energy levels in the host band gap. It is shown that through the combination of the crystal field theory and ab initio methods of electronic structure calculations it is possible to build up the complete energy level scheme of a doped crystal, which includes the host’s electronic band structure and impurity ion energy levels superimposed onto it.
A new model that links together the energies of the spin-forbidden transitions of transition metal ions (Mn4+, Cr3+, Ni2+) with the covalent effects experienced by those ions is also outlined. Several recommendations on how to tune the emission wavelengths of the Mn4+
2Eg – 4A2g transition are outlined.
All shown examples are compared with the corresponding experimental results (whenever possible). Predictive potential of the presented models is discussed.
Enhanced Photo-Bioelectrochemical Energy Conversion By Genetically Engineered Cyanobacteria
Authors: Sekar Narendran , Ramasamy Ramaraja P. 
Published: February 2020

Photosynthetic energy conversion using natural systems is increasingly being investigated in the recent years. Photosynthetic microorganisms such as cyanobacteria exhibit light dependent electrogenic characteristics in photo bio-electrochemical cells1 (PBEC) and/or photosynthetic microbial fuel cells2 (PMFC) that generate substantial yet lower photocurrents than their photovoltaics counterparts. Recently we demonstrated that a cyanobacterium named Nostoc sp. employed in PBEC could generate up to 35 mW/m2 even in a non-engineered PBEC. With the insights obtained from our previous research2, a novel and successful attempt has been made in the current study to genetically engineer the cyanobacteria to further enhance its extracellular electron transfer. The cyanobacterium Synechococcus elongatus PCC7942 was genetically engineered to express a non-native outer membrane redox protein. The engineered S. elongatus exhibited very high extracellular electron transfer ability resulting in ~ 9 fold higher photocurrent generation on the anode of a PBEC than the corresponding wild-type cyanobacterium. This work highlights the scope for enhancing photocurrent generation in cyanobacteria thereby benefiting faster advancement of the PMFC technology.
References

J. M. Pisciotta, Y. Zou and I. V. Baskakov, PLoS One, 2010, 5, 10

N. Sekar, Y. Umasankar, R. Ramasamy Phys.Chem.Chem.Phys., 2014,16,7862

Figure 1
Fabrication of Low-Invasive Patch Glucose Sensors
Authors: Li Jiang , Hiura Kentaro , Yasuzawa Mikito , Fuchiwaki Yusuke 
Published: February 2020

1. Introduction
Recently, implantable glucose sensors for continuous glucose monitoring (CGM) are provided significant advantage on diabetic health care, since it not only lower the physical and mental load on glucose measurement, but also present continuous glucose trend, which is useful for treatment evaluation. However, since the length of sensor device inserted in skin is about 1 cm, development of lower invasive CGM system is expected for the improvement of diabetic patients' quality of life.
In this study, a fine needle tube type glucose sensor, which has sensing region at the tip of a fine tapered electrode, was proposed. The schematic illustration of such glucose sensor is shown in Fig. 1. Since the sensing region is at the tip of tapered electrode, it only requires the sensor tip to be implanted in the tissue for glucose monitoring, which makes it possible to perform as a patch type sensor instead of implanting sensor. Fine platinum-iridium alloy wire was placed inside the tapered PEEK tube and glucose oxidase (GOx) was immobilized on the surface of platinum electrode by using the combination of electrodeposition and electropolymerization technique. Properties of the obtained sensor were evaluated mainly by in vitro measurement.
2．Experimental
Pt-Ir alloy wire (0.17 mm in diameter) was fixed in a PEEK tube (0.20 mm in inner diameter and 0.8 mm in outer diameter). The prepared assembly was mechanically polished to form a fine tapered needle structure. According to the procedure proposed by Wilson's group [1], the biosensor was prepared.
The amperometric responses of the prepared electrodes to glucose were examined at 40°C in a 0.1 M PBS (pH 7.4) containing 0.1 M NaCl, by measuring the electrooxidation current at a potential of 0.6 V (vs. Ag/AgCl).
3．Results
Current-time response of the prepared electrode was investigated. The response current increased with increasing concentration of glucose. Response current provided good linear relationship with glucose concentration. Variation of response in time on the prepared electrode was investigated for two weeks. The response of the electrode was measured at 40°C and stored in phosphate buffer at 4°C when not in use. After initial increase of response current for few days, the electrode provided stable response current.
(1) N. Matsumoto, X. Chen and G. S. Wilson, Anal Chem, 74, 368 (2002).

Figure 1
Bringing Components to Solar Fuels Prototypes: Material Discovery, Interface Engineering, and Integration
Authors: Sharp Ian D. 
Published: February 2020

To achieve efficient and durable devices for spontaneous water splitting, it is necessary to overcome thermodynamic limitations on material stability, integrate catalysts with light absorbers, and engineer interfaces to reduce recombination loss. Central to this work is the discovery of new materials and methods, combined with the translational research required for their incorporation into prototypes. In our work, we use advanced x-ray and optical methods to understand the basic electronic structure, photocarrier dynamics, and chemical instabilities of existing semiconductor materials. This information allows for insights into the mechanisms of energy conversion and efficiency loss, as well as refinement of computational models for improved prediction of new semiconductors possessing desired band gaps, charge transport properties, and stabilities required for improved half-cell performance. Informed by these predictions, materials discovery efforts are aimed at synthesizing specific compositions for further investigation. These materials are typically compound thin film semiconductors, in which composition non-uniformities, structure, and morphology affect photoactivity. Probing these properties across different length scales, as well as their transformations in operational environments, allows for determination of chemical vulnerabilities and electronic deficiencies. Since these materials are typically characterized by poor intrinsic catalytic activity, it is generally necessary to integrate catalysts onto their surfaces. Process development and interface engineering are required to achieve desired catalyst composition and structure, while enabling efficient separation and transfer of photocarriers from semiconductor to catalyst. Since the performance of integrated systems is often governed by defect properties that are difficult to predict, combinatorial studies of catalyst/semiconductor assemblies are used to aid in the discovery of efficient interfaces. Finally, advances made at the half-cell level must be incorporated into prototypes capable of spontaneous overall water splitting and product separation, which impose strict requirements on operational conditions, light transmission paths, and physical scale. Key examples of research spanning material and mechanism discovery, development, and integration into prototypes will be given.
Nitrogen Doped Hydrothermal Carbon for Supercapacitors
Authors: Donne Scott W , Latham Kenneth 
Published: February 2020

Although pure carbon materials have been readily adopted for energy storage applications, recent years have seen an increase in studies incorporating heteroatoms into the carbon matrix for energy storage applications. The doping of carbon materials with heteroatoms increases performance significantly in energy storage applications, specifically supercapacitors. This increase in performance is due to heteroatoms providing electrochemically active sites in which highly reversible redox reactions can occur (pseudocapacitance), boosting the overall performance of the electrode. This has led to the widespread development of doped carbon materials incorporating nitrogen, phosphorus, sulphur and various transition metals into almost every allotrope of carbon.
Currently, a number of technologies have been utilized to dope nitrogen into carbon structures, such as electric arc, pyrolysis, hydrothermal and pre/post treatments with nitrogen sources. Of these, hydrothermal carbonization (HTC) is one of the most promising techniques in carbon materials research. In comparison to other carbonization techniques, HTC offers an environmentally friendly approach to the formation of highly functionalized, doped carbon structures from renewable sources as carbonization occurs under water at substantially lower temperatures (180°-300°C). Furthermore, heteroatoms incorporation, chemical and structural morphology as well as surface functionality can be easily controlled through the manipulation of the treatment conditions, solution pH and addition of soluble additives (i.e., (NH4)2SO4.
In this study, we have investigated the chemical structure via NEXAFS, morphology and electrochemical performance of hydrothermal carbons produced from sucrose doped with different ammonium salts. This produced nitrogen doped carbons with a spherical morphology with a wide variety of oxygen and nitrogen functionalities spread across the surface. Electrochemically, these carbons displayed a wide range of psudocapacitive behaviour as well as electrical double layer capacitance, delivering up to 200 F/g in three electrode cells with 1 M KOH as the electrolyte.
Abnormal Shrinkage upon Nickel Oxidation at Low Temperatures
Authors: Yashiro Keiji , Nakamura Takashi , Yamaji Katsuhiko , Hashimoto Shin-ichi , Amezawa Koji , Kawada Tatsuya 
Published: February 2020

Chemical- and mechanical stability of Ni-YSZ cermet is an important factor for long-term operation of SOFCs, because the cermet is often used as not only an anode but a support of the cell. It has been reported that microstructure of the cermet changes upon reduction and oxidation of nickel; and that nickel sintering takes place during long-term operation. These phenomena lead to deterioration of cell performance.
It is well known that oxidation of Ni causes increase in volume. However we recently found that Ni-YSZ cermet was unexpectedly shrunk during the oxidation in the temperature range less than 500 °C. To clarify this phenomenon, thermal expansion behavior of sintered nickel metal was measured in oxidizing atmosphere by a dilatometry. Oxygen partial pressure and temperature varied from 10-3 to 0.2 bar and room temperature to 700 °C, respectively. The extraordinary shrinkage behavior was observed in temperature range between 300-500 °C. The amount of shrinkage depended on oxygen partial pressure and temperature ramp. Maximum shrinkage of 1% was observed in 20%O2-N2at heating rate of 1 °C/min.
Microstructure change of nickel was also observed by a scanning electron microscope before and after oxidation treatment at 400 °C in order to clarify the causes of volume increase. Comparing the microstructure before and after oxidation, it seemed that nickel sintering was accelerated by oxidation of nickel.
Modeling Intermediate Temperature Protonic Ceramic Fuel Cells
Authors: Albrecht Kevin J , Duan Chuancheng , O'Hayre Ryan , Braun Robert J. 
Published: February 2020

Protonic ceramics fuel cells (PCFC) have emerged as a promising candidate for distributed power generation and synthetic fuel production. The cells offer the potential for reduced temperature operation (~500°C) which enables faster startup times, longer life, and lower material cost components to be used compared to their oxygen ion conducting counterparts. The development of a protonic ceramic fuel cell computational modeling tool is imperative to the design and implementation of systems. A framework is presented for a predictive cell-level, interface charge transfer PCFC model capturing the mixed conducting nature of the protonic ceramic materials. The model employs a 1-D channel-level modeling strategy (Fig. 1) where fuel depletion and flow configuration effects are resolved and coupled to a semi-empirical electrochemical model. Modeling results calibrated against experimental data of a state-of-the-art PCFC composition are presented.
The lower cell temperature and hydrogen removal from the anode channel present unique operational features which are considered in the present work. In particular, a thermodynamic analysis is presented for operating regimes where solid carbon formation is not thermodynamically favorable. Simulation results are presented for the operation of the cell over a variety of operational regimes. Model predicted distributions of gas phase species, temperature, and local current density are resolved. The model predicted cell performance when operating on a humidified methane fuel source with steam-to-carbon ratio (S/C) of 2.4 at 500oC and 80% utilization indicates a power density greater than 0.100 W/cm2 is attainable at an average current density of 0.15 A/cm2. Model-predicted cell performance is explored under various operating conditions (Temperature, utilization, S/C) and an evaluation of reactant flow configuration (co- vs. counter-flow) is also presented.

Figure 1
Analysis of Interfacial Processes at the SOFC Electrodes by I
n-Situ Raman Spectroscopy
Authors: Agarkov Dmitrii , Burmistrov Ilya , Tsybrov Fedor , Tartakovskii Ilya , Kharton Vladislav , Bredikhin Sergey , Kveder Vitaly 
Published: February 2020

Kinetics of redox reactions and the variations of real charge-carrier concentrations across the SOFC electrode / electrolyte interfaces have critical importance for the fuel cell performance. The microscopic mechanisms of electrochemical processes in the vicinity of triple-phase boundary (TPB) can be assessed employing impedance spectroscopy, current-voltage measurements and various pulse techniques. Except for the micro-electrode approaches, however, these methods are cumulative. Moreover, unambiguous interpretation of the electrochemical measurement results requires, as a rule, to introduce complimentary experimental methods and/or to use simplified models. The present work is centered on the developments of a new combined technique for in-situ Raman spectroscopy studies of local chemical and electrochemical reactions, phase transitions, strains and morphological alterations in the SOFC electrodes under working conditions. The Raman spectroscopy was already successfully used to investigate both cathodic [1,2] and anodic [3] processes in SOFC, but the resultant information was mainly related to outer boundaries of the model electrochemical cells, primarily electrode surface, due to low penetration depth of the excitation radiation. The most important zones of the electrode systems, where the electrochemical reactions occur and ionic charge carriers are generated, cannot be achieved viewing the surface and edge areas. In the present work, this problem was solved by employing optically transparent, single-crystal membranes made of 10 mol.% Sc2O3 and 1% mol.% Y2O3 stabilized zirconia (10Sc1YSZ). In order to provide simultaneous Raman and electrochemical measurements of the cell placed under an oxygen chemical potential gradient, such as air/H2, a special controlled-atmosphere chamber was elaborated and tested. An appropriate selection of the electrodes geometry makes it possible to directly collect Raman spectra from the TPB zone, passing the beam through single-crystal solid electrolyte onto the interface, as a function of temperature, atmosphere, current density and/or overpotential. The results of case studies focused on redox kinetics of Ni-containing cermet anodes, are presented.
This work was supported by grant 14-29-04031 of Russian Foundation for Basic Research.
References

S. Loridant, L. Abello, E. Siebert, G. Lucazeau, Solid State Ion. 78 (1995) 249-258

K. Blinn, H. Abernathy, M.Liu, Advances in Solid Oxide Fuel Cells V. (2010) 63-73

W. Bessler, M.Vogler, H. Stoermer, D. Gerthsen, A. Utz, A. Weber, E. Ivers-Tiffee, Phys. Chem. Chem. Phys., 12 (2010) 13888-13903