bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Deionization and Energy Recovery in Capacitive Systems with Inverted Operation Characteristics
Authors: Omosebi Ayokunle , Li Zhiao , Gao Xin , Holubowitch Nicolas , Landon James , Cramer Aaron M , Liu Kunlei 
Published: February 2020

Capacitive deionization (CDI) continues to emerge as a viable option for the treatment of saline streams with up to brackish levels of ionic contaminants. CDI functions similar to a capacitor, storing ions from a liquid stream onto highly porous electrodes with the aid of an applied electric field. When the pores become saturated, the electric field can be reduced or reversed to discharge the previously stored ions and form a concentrate stream [1]. At the same time, the electronic energy input to the cell during ion storage can be recovered to power auxiliary devices or coupled CDI units. The coupling of CDI cells offers not only the ability to lower the energy requirements for cell operation, but also the possibility of semi-continuous CDI operation. With much effort devoted to materials development and performance enhancements, there have been few reports on energy recovery in CDI literature. Of these, discharging a charged CDI cell over a resistive load, direct connection of CDI cells, and the use of buck-boost DC-DC converters have been demonstrated. In this work, parallel CDI cells are integrated with a DC-DC converter based on a Ćuk topology (Figure 1) to show active energy recovery from a discharging cell and subsequent deionization with a secondary cell using energy stored in the initial charged cell. Unlike buck-boost, the Ćuk topology incorporates a power supply that compensates for energy losses during the electron transfer process, thereby allowing the system to simultaneously transfer energy and meet its desalination goals.
Inverted capacitive deionization (iCDI) was recently demonstrated where deionization was accomplished by a polarity difference between chemical surface charges on electrode pairs that facilitates adsorption of ions from solution [2]. Conversely to classical CDI, cell discharge is accomplished by applying an external electric field. We have improved upon the iCDI cell architecture by incorporating ion-selective membranes to form a new inverted membrane capacitive deionization cell (iMCDI). We will demonstrate energy recovery results for both the iCDI and iMCDI cells, and explore the influence of converter operation and cell architecture on energy recovery.

References

[1] M.A. Anderson, A.L. Cudero, J. Palma, Electrochim. Acta 55 (2010) 3845.
[2] X. Gao, A. Omosebi, J. Landon, K. Liu, Energy & Environmental Science 8 (2015) 897.

Acknowledgements

These authors are grateful to the U.S.-China Clean Energy Research Center, U.S. Department of Energy (DE-PI0000017) for project funding.

Figure 1
Creation of 4fn-4fn-15d1 Transition Energy Diagram of Trivalent Lanthanide Ions in Fluorides Based on First-Principles Calculations
Authors: Ogasawara Kazuyoshi 
Published: February 2020

The theoretical prediction of the 4fn-4fn-15d1 transition energies of lanthanides in crystals is an important issue in the development of novel luminescent materials such as solid-state lasers or phosphors. In our previous work, the first-principles calculations of the entire multiplet structures of lanthanide (Ln) ions in LiYF4 (YLF) corresponding to 4fn and 4fn-15d1 configurations were performed using the relativistic discrete variational multi-electron (DVME) method [1]. However, the lowest 4fn-4fn-15d1transition energy was overestimated for light lanthanides while it was underestimated for heavy lanthanides. In this work, in order to improve the accuracy of the theoretical transition energy, a correction based on the molecular orbital (MO) calculation in the Slater’s transition state was introduced.
The LnF8 clusters were constructed based on the crystal structures of YLF and CaF2. The fully-relativistic MO calculations were performed using the relativistic DV-Xα code. The multiplet calculations were performed using the relativistic DVME code. The Slater determinants corresponding to 4fn and 4fn-15d1 configurations were constructed from the four-component relativistic MOs and used as the basis functions to diagonalize the relativistic many-electron Hamiltonian. In order to correct the errors in the transition energy, MO calculations in the Slater’s transition state where a half electron was excited from the Ln 4f level to the Ln 5d level were also performed. A constant correction term was added to the diagonal matrix element of the many-electron Hamiltonian for 4fn-15d1 configuration so that the 4fn -4fn-15d1transition energy is consistent with the 4f-5d transition energy obtained by the MO calculation in the Slater’s transition state.
The diagrams representing the lowest 4fn-4fn-15d1transition energies of trivalent lanthanide ions in YLF calculated with and without the above correction are shown in Fig. 1. The overestimation in the light lanthanides and the underestimation in the heavy lanthanides are significantly reduced by the correction and the theoretical transition energies approached to the experimental values in the literature [2-5].
References
[1] K. Ogasawara, S. Watanabe, H. Toyoshima, M.G. Brik, ”Handbook on Physics and Chemistry of Rare Earths”, 37, Chapter 231 (Elsevier,2007).
[2] A. Meijerink and R.T. Wegh, Mater. Sci. Forum, 315-317, 11 (1999).
[3] L. van Pieterson et al., Phys. Rev. B, 65, 045113 (2002).
[4] L. van Pieterson et al., Phys. Rev. B, 65, 045114 (2002).
[5] M. Kirm et al., Phys. Rev. B, 75, 075111 (2007).

Figure 1
(Invited) Cyborg Insect: Insect Computer Hybrid Robot
Authors: Poon Kee Chun , Tan Desmond Chun Long , Li Yao , Cao Feng , Vo Doan Tat Thang , Sato Hirotaka 
Published: February 2020

Insect-computer hybrid robot, often referred as to ‘Cyborg Insect’, is the fusion of living insect and miniature radio-enabled wireless electrical stimulator to control the locomotion of the insect platform in walking and flight. The miniature stimulator is mounted on the back of the living insect and metal thin wires are implanted into neuromuscular sites of our interest to electrically stimulate for eliciting experimentalist’s desired motor actions and behaviors.
Insects exhibit amazing modes of locomotion. They float, swim, crawl, jump, run, fly and they even walk on water. They do this with such efficiency, sophistication and elegance of function across a vast size range that they have mastered locomotion on almost every terrain on the earth. Very recently researchers have started building ultra-small data recording systems for flying insects and tried to stimulate insects (moths, locusts, beetles) to induce desired actions.
The miniature stimulator (~1.3 g in total mass) consisted of a custom PCB (printed circuit board), an off-the-shelf microcontroller, a rechargeable micro battery and thin-wire electrodes. We employed Mecynorhina torquata, a giant flower beetle as the insect platform for the hybrid robot (10 g, 6 cm, 3 g payload capacity in flight). The stimulator assembly was mounted on the beetle’s pronotum and the terminals of wire electrodes were inserted into the optic lobes, brain, basilar flight muscles and dorsal thorax (counter electrode).
Flight initiation was triggered by applying 2 - 4 V, 100 Hz, 20 % duty cycle, biphasic square pulse trains between the two electrodes implanted into the optic lobes, massive neural clusters of compound eyes. Cessation was triggered by a single DC pulse applied to the same sites as the initiation. The wing power was decreased (and thus throttle down) when the same 100 Hz pulse trains were applied to the brain. Turnings were elicited by applying the same pulse trains to either the left or right basilar flight muscle. The beetle turned in opposite direction to stimulated side: left turn was, for example, conducted by the right side stimulation.
On the other hand, toward a self-powering unit for the insect-computer hybrid robot, we have proposed a miniature biofuel cell implantable into living insect to generate electrical energy by consuming energy source, for example, saccharide. For that we have developed nanoparticle catalysts for oxygen reduction reaction such as P or B doped Pd, denoted by Pd-P or Pd-B. By doping these non-metal elements into Pd, the catalytic activity of Pd was drastivally enhanced. These Pd-P and Pd-B catalysts were facilely synthesized by a electroless deposition process using hypophosphate and DMAB (dimethylaminoborane) as reducing agent, respectively.
In the presentation, we will show the demonstration of insect locomotion control and the experimental data and discussion on the enhanced catalytic activities of the Pd nanoparticle catalysts.

Figure 1
Quantitative Assessment of Channeling Mechanisms in Nanoscale Catalytic Architectures
Authors: Earl Erica , Calabrese Barton Scott 
Published: February 2020

Highly efficient catalytic cascades are found in nature, where the efficiency of multi-step biochemical pathways is enhanced by substrate channeling, wherein the transport of intermediates from on active site to the next is managed by physical interactions [1]. Modes of substrate channeling include proximity between active sites, confinement [2], electrostatic interactions [3], and surface adsorption. Investigating these natural pathways could lead to the development of innovative designs for catalytic systems. We investigate the efficiency of these pathways through numerical continuum modeling, to identify their limits and the extent to which they can interact. The model considers transport between two active sites and includes both transport and kinetic properties of the system (Figure 1). The effectiveness of this model is quantified by yield of the second reaction and by flux control coefficients (FCCs) [4]. FCCs have traditionally been applied to purely kinetic systems, but will be expanded to incorporate one that includes mass transport. Acknowledgement We gratefully acknowledge support from Army Research Office MURI (#W911NF1410263) via The University of Utah. References 1. I. Wheeldon et al., Nat. Chem., 8, 299–309 (2016) doi:10.1038/nchem.2459. 2. C. C. Hyde, S. a. Ahmed, E. a. Padlan, E. W. Miles, and D. R. Davies, J. Biol. Chem., 263, 17857–71 (1988). 3. A. H. Elcock, M. J. Potter, D. a Matthews, D. R. Knighton, and J. A. McCammon, J. Mol. Biol., 262, 370–374 (1996) doi:10.1006/jmbi.1996.0520. 4. D. A. Fell, Biochem. J., 286, 313–30 (1992).

Figure 1
Sodium Cobalt Oxide As a Non-Platinum Cathode Catalyst for Microbial Fuel Cells
Authors: Ichihashi Osamu , Hirooka Kayako , Takeguchi Tatsuya , Kusui Takashi 
Published: February 2020

Microbial fuel cell is a device that can achieve wastewater treatment and power generation simultaneously. For the practical application of microbial fuel cell, development of alternative cathode catalyst for platinum is necessary. In this study, a kind of sodium cobalt oxide, NaCo2O4was investigated, because estimated cobalt reserve is 100 times higher than platinum, and its price is about one thousandth.
Catalyst ink was prepared by mixing NaCo2O4powder with carbon black powder and Nafion dispersion. Then cathode was fabricated by applying the ink to PTFE treated carbon paper. Cathode with Pt catalyst and that with activated carbon (NORIT SX PLUS) were also prepared for comparison.ORR activity of the cathodes was measured by linear sweep voltammetry (LSV).
Oxygen reduction reaction (ORR) activity of NaCo2O4 cathode increased 15-25 times by the addition of carbon black as conductive assistant material in catalyst ink. Two kinds of carbon black were tested, and a cathode with Ketjen black showed better ORR activity than that with Vulcan XC-72. By increasing coating amount of catalyst ink from 2mg/cm2 (NaCo2O4) to 4mg/cm2, ORR activity increased 1.6 - 1.7 times, which was equivalent to 50-60% of Pt catalyst (Fig) . Gram based ORR activity of this catalyst was higher than that of activated carbon (NORIT SX PLUS) catalyst (Fig). The NaCo2O4 cathode having highest ORR activity was built into a pre-acclimated MFC, and then used for the treatment of synthetic wastewater. The current density was about 3A/m2, which was a little lower than the value during the operation equipped with a Pt cathode (about 4A/m2). However, any problems such as a decrease in electricity generation were not observed in several days of operation. Power density curve of the MFC equipped with the NaCo2O4 cathode was obtained by the LSV measurement , and the maximum current density was 0.58 W/m2, which is about a half of the density achieved by a Pt cathode.
Further research on the preparation condition of the cathode, such as the amount of conductive assistant material, the amount of binder, and the coating amounts of the catalyst ink, would probably contribute to further improve the cathode ORR activity, which would improve electricity generation performance of a MFC.

Figure 1
Electrochemical Reduction of Primary Alkyl Halides with the Aid of a Structurally Modified Nickel Salen Catalyst
Authors: Goodson Austin , McGuire Caitlyn M. , Mubarak Mohammad S. , Peters Dennis G 
Published: February 2020

Electrochemical reduction of primary alkyl halides has been extensively investigated through the use of [[2,2′-[1,2-ethanediylbis(nitrilomethylidyne)]bis[phenolato]]-(N,N′,O,O′)]nickel(II) (nickel salen) as a procatalyst. In these studies, there was a proclivity for the grafting of alkyl chains onto the imino (C=N) bonds of the nickel species, which lowers the yields of the desired reduction products significantly.1,2 In the present study, we have used a structurally modified nickel(II) salen-like species possessing methyl protecting groups to improve the performance of the catalyst.3 The efficacy of this modified nickel species as a procatalyst for electrochemical reductions of 1-bromo- and 1-iododecane has been studied with the aid of cyclic voltammetry and controlled-potential (bulk) electrolysis in N,N-dimethylformamide (DMF) containing tetra-n-butylammonium tetrafluoroborate (TBABF4) as a supporting electrolyte. Results indicate that a majority of the reduced substrate appears as a dimeric species (n-eicosane); in addition, smaller amounts of n-decane and 1-decene are found. A mechanism is proposed for the process that involves radical intermediates. Several products corresponding to the incorporation of DMF fragments into the reduced substrate were detected. Use of this procatalyst has also been investigated to overcome solvent incorporation under similar conditions in an acetonitrile medium.
References

Goken, D.M.; Ischay, M. A.; Peters, D. G.; Tomaszewski, J. W.; Karty, J. A.; Reilly, J. P.; Mubarak, M. S. J. Electrochem. Soc.
2006, 153, E71–E77.

Raess, P. W.; Mubarak, M. S.; Ischay, M. A.; Foley, M. P.; Jennermann, T. B.; Raghavachari, K.; Peters, D. G. J. Electroanal. Chem. 2007, 603, 124–134.

Ourari, A.; Ouennoughi, A.; Aggoun, D.; Mubarak, M. S.; Pasciak, E. M.; Peters, D. G. Polyhedron
2014, 67, 59–64.

Figure 1
(Invited) Electron-Transfer Approaches to Metal-Free Ring-Opening Metathesis Polymerization
Authors: Boydston Andrew J , Goetz Adam E , Pascual Laura M M , Ashikari Yosuke , Ogawa Kelli A 
Published: February 2020

We have recently discovered a method of performing ring-opening metathesis polymerization (ROMP) via an electrochemically-mediated process involving electron rich olefin initiators and norbornene-based monomers. The method expands upon the powerful, metal-mediated approaches toward ROMP that have been successful for the production of polymers with precise structure and function. A key distinction is our ability to integrate organocatalysis and electro-organic synthesis to circumvent the need for metal-based initiators. In this way, electromediated ROMP has opened the doorway to metal-free protocols that have the potential to provide materials with unique optical, electronic, and materials properties.
Inspired by the pioneering work of Chiba and coworkers, we explored the hypothesis that anodic oxidation of vinyl ethers could be used to initiate and mediate polymerization of strained cycloalkenes via a ROMP mechanism. Toward this end, we evaluated vinyl ethers in combination with norbornene as a common ROMP monomer to determine the viability of electromediated ROMP. Although initial conversions of norbornene to polynorbornene were low, we were able to confirm initiation by the vinyl ether and successful polymer formation. Consideration of the key limiting factors in our initial electromediated ROMP conditions, which appeared to be poor solubility of norbornene and polynorbornene, led us to consider photoredox and indirect electrolysis approach. We will discuss recent successes with organic photo-oxidants capable of facilitating metal-free ROMP in high conversions with excellent temporal control. In addition, we will present our latest results on the use of organic mediators to facilitate metal-free ROMP via indirect electrolysis.
Highly Soluble Quinones As Active Materials for Nonaqueous Redox Flow Batteries
Authors: Takenaka Keisuke , Shimizu Akihiro , Yoshida Jun-ichi 
Published: February 2020

The redox flow battery has received significant research interest as a large scale energy storage system for renewable-energy sources. Although the all-vanadium aqueous redox flow battery has been most developed, its energy density is not sufficient mainly because of narrow electrochemical stability window of water. Therefore, recent efforts have shifted to developing nonaqueous redox flow batteries because they can achieve higher voltage due to wider electrochemical stability window of nonaqueous electrolytes. However, nonaqueous redox flow batteries generally suffer from insufficient energy densities because of low solubility of organic active materials in nonaqueous electrolytes.
In this study, we designed and synthesized two highly soluble organic active materials, benzoquinone 1 and naphthoquinone 2 having diethylene glycol mono methyl ether groups. Both 1 and 2 were highly soluble in propylene carbonate (PC). Charge-discharge properties of the batteries using 1 and 2 as organic active materials were measured in LiBF4/PC using a cell equipped with a carbon fiber anode, a lithium-metal anode, and a glass filter separator. The charge-discharge measurements showed that 1 and 2 exhibited high voltages of ca. 3 V and good charge-discharge properties. Notably, 2 showed a higher energy density than conventional all-vanadium aqueous redox flow batteries.
(Invited) One-Step Aerobic Oxygenation of Hydrocarbons By Electron Transfer
Authors: Ohkubo Kei 
Published: February 2020

Photoinduced oxygenation of neat cyclohexane in the presence of O2 occurred under visible light irradiation of 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) which acts as a super photooxidant [1-3]. The products detected by GC and NMR analyses were cyclohexanol, cyclohexanone and cyclohexane hydroperoxide with 70, 40, 210% yields, respectively. When cyclohexane was replaced by n-butane, n-pentane and 3-methylpentane, the oxygenation reactions also took place to form the corresponding oxygenated products under the otherwise same photochemical reaction conditions.
The reaction mechanism was clarified by femtosecond and nanosecond laser flash photolysis measurements. Femtosecond laser irradiation of DDQ in cyclohexane results in formation of the singlet excited state of DDQ (1DDQ*; * denotes the excited state) detected as a transient absorption band at 480 nm. The band of 1DDQ* decayed with increasing a new absorption band at 590 nm and 630 nm, which are assigned to 3DDQ* and DDQ semiquinone radical anion (DDQ•–), respectively. Thus, the photocatalytic reactions are initiated by electron-transfer oxidation of cyclohexane (CyH) with 1DDQ* to form the cyclohexane radical cation (CyH•+), which reacts with DDQ•– to produce the cyclohexyl radical (Cy•) and DDQ semiquinone radical (DDQH•). The triplet excited state (3DDQ*) generated by the intersystem crossing of 3DDQ* is also reacts with CyH to produce radical ion pair. Cy• reacts with O2to produce the final oxygenated products via radical chain process.
[1] Ohkubo, K.; Fujimoto, A.; Fukuzumi, S. J. Am. Chem. Soc.
2013, 135, 5368.
[2] Ohkubo, K.; Hirose, K.; Fukuzumi, S. Chem.–Eur. J.
2015, 21, 2855.
[3] Fukuzumi, S.; Ohkubo, K. Asian J. Org. Chem.
2015, 4, 836 (Focus Review).
Microelectrode Arrays and the Move Toward Practical Applications
Authors: Moeller Kevin D , Uppal Sakshi , Graaf Matthew , Yeh Nai-Hua , Li Weiqiang 
Published: February 2020

Microelectrode arrays have great potential as a platform for monitoring the interactions between small molecules and biological receptors in “real-time”. For this reason, we have developed new polymer coatings for the arrays, new site-selective methods for building or placing molecules by electrodes in the arrays, new methods for characterizing molecules build on the arrays, and new approaches to detecting molecular interactions that occur on the array.1

With these tools in place, attention is now being turned toward using the arrays to gather biological data on molecules of interest. That effort has at times been successful, and at times raised new challenges for controlling the surface of the arrays. The talk to be presented will focus on two such problems.
One of the reasons the arrays were developed was so that we could examine “weaker” interactions without the washing steps required by many immunological studies. One such challenge involved the binding of the v107 peptide to its VEGF target (Scheme 2). In particular, we were interested in comparing the binding of peptide analogs to both the human and murine VEGF proteins. While homology studies suggested that the binding should be similar, we hoped to experimentally verify that suggestion and develop a cheap easy way to probe such interactions. V107 is known to bind the human VEGF with micromolar affinity (Scheme 2). The suitability of the arrays for this study will be highlighted with both receptors leading to very similar binding curves with the surface bound v107 peptide.
While interactions with stronger affinity can be seen very well, there are challenges associated with the arrays amplifying the signals. For example, our interest in using the arrays to probe interactions between small molecules and their G-protein targets has been hampered by the signal being amplified to a point that cannot be observed on the arrays. In this talk, an approach to solving this problem will be presented.
1. For an instructional review see: Graaf, M. D.; Moeller, K. D. Langmuir
2015, 31, 7697.

Figure 1
A New Family of Perovskite Catalysts for Oxygenevolution Reaction in Alkaline Media: BaNiO3 and BaNi0.83O
Authors: Han Byungchan , Hwang Jeemin 
Published: February 2020

Establishment of sustainable energy society has been strong driving force to develop cost-effective and highly active catalysts for energy conversion and storage devices such as metal-air batteries and electrochemical water splitting systems. This is because the oxygen evolution reaction (OER), a vital reaction for the operation, is substantially sluggish even with precious metalsbased catalysts. Here, we show for the first time that a hexagonal perovskite BaNiO3 can be highly functional catalyst for OER in alkaline media. We identify that the BaNiO3 performs OER activity at least an order of magnitude higher than an IrO2 catalyst. Using integrated density functional theory calculations and experimental validations we unveil the underlying mechanism is originatedfrom structural transformation from BaNiO3 to BaNi0.83O2.5 (Ba6Ni5O15) over the OER cycling process.

Figure 1