Anionic Effects on Solvate Ionic Liquid Electrolytes in Rechargeable Lithium–Sulfur Batteries

Ueno, Kazuhide,Park, Jun-Woo,Yamazaki, Azusa,Mandai, Toshihiko,Tachikawa, Naoki,Dokko, Kaoru,Watanabe, Masayoshi American Chemical Society 2013 JOURNAL OF PHYSICAL CHEMISTRY C - Vol.117 No.40

<P>A series of equimolar mixtures of Li salts (LiX) and glymes (triglyme (G3) and tetraglyme (G4)), [Li(glyme)]X with different anions (X: [N(SO<SUB>2</SUB>C<SUB>2</SUB>F<SUB>5</SUB>)<SUB>2</SUB>] = [BETI]; [N(SO<SUB>2</SUB>CF<SUB>3</SUB>)<SUB>2</SUB>] = [TFSA]; [CF<SUB>3</SUB>SO<SUB>3</SUB>] = [OTf]; BF<SUB>4</SUB>; NO<SUB>3</SUB>), were used as electrolytes to study the anionic effects of [Li(glyme)]X on the performance of lithium–sulfur (Li–S) batteries. The dissolution of lithium polysulfides (Li<SUB>2</SUB>S<SUB><I>m</I></SUB>), which are discharge products of elemental sulfur, was significantly suppressed in the solvate ionic liquid (IL) electrolytes, as seen in [Li(G4)][BETI] and [Li(glyme)][TFSA], wherein all of the glymes participated in the formation of the complex cation [Li(glyme)]<SUP>+</SUP>. It was found that NO<SUB>3</SUB> anions were irreversibly reduced at the composite cathode during discharge and BF<SUB>4</SUB> anions formed unexpected byproducts through a chemical reaction with the polysulfide anions. Successful charge/discharge of Li–S cell could not be performed in [Li(glyme)]X in the presence of these anions because of the undesired side reactions. The solvate IL [Li(G4)][BETI] was found to be electrochemically stable in the Li–S cell and allowed a stable operation with a capacity of 600–700 mAh·g<SUP>–1</SUP> and a Coulombic efficiency of 98.5% over 100 cycles, similar to that achieved by [Li(glyme)][TFSA]. In contrast, the Li–S cell with a concentrated electrolyte solution, [Li(G3)][OTf], showed a much lower capacity and Coulombic efficiency.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2013/jpccck.2013.117.issue-40/jp407158y/production/images/medium/jp-2013-07158y_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp407158y'>ACS Electronic Supporting Info</A></P>

Efficacy of TachoSil, a Fibrin-Based Hemostat, for Anterior Lumbar Spine Surgery

Jo Watanabe,Seiji Ohtori,Sumihisa Orita,Kazuyo Yamauchi,Yawara Eguchi,Yasuchika Aoki,Junichi Nakamura,Miyako Suzuki,Kazuhide Inage,Jun Sato,Yasuhiro Shiga,Koki Abe,Kazuki Fujimoto,Hirohito Kanamoto,Ei 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.5

Study Design: Retrospective case series. Purpose: To examine the efficacy of TachoSil for vessel injury in 6 patients who underwent anterior lumbar fusion surgery (ALF). Overview of Literature: ALF for the lumbar spine has a high rate of success, although intraoperative concerns and iatrogenic complications are known, and injury of a major vessel is sometimes a complication. The efficacy of TachoSil, a fibrin-based hemostat, has been reported for several types of surgery; however, use of TachoSil for ALF surgery has not been described. Here, we report on the efficacy of TachoSil in 6 patients, who underwent ALF after vascular surgeons having difficulty in repairing vessels. Methods: Two man and 4 women with average age of 50.8±10.9 (mean±standard deviation) were diagnosed with a vertebral tumor (2 patients), L4 degenerative spondylolisthesis (2 patients), and L5 spondylolytic spondylolisthesis (2 patients) and underwent ALF. The blood vessels injured included the common iliac vein in 2 patients and a branch of a segmental artery from the aorta in 4 patients. We consulted a vascular surgeon to suture or repair the vessels during surgery, and although the vascular surgeon attempted to address the injuries, suturing or repair was not possible in these cases. For this reason, we used TachoSil to repair the injury in the vessels walls or to stop the bleeding. Results: Time to pressure hemostasis using TachoSil was 34±12 minutes, and total blood loss was 1,488±1,711 mL. Nevertheless, all vessel injuries were controlled by the use of TachoSil. Conclusions: We recommend the use of TachoSil for vessel injuries that vascular surgeons cannot suture or repair during ALF surgery.

The 5th Seoul International Digestive Disease Symposium : Interleukin-1beta and tumor necrosis factor-alpha cause recurrence of experimental gastric ulcer : A key mechanism

(Tetsuo Arakawa),(Toshio Watanabe),(Kazunari Tominaga),(Yasuhiro Fujiwara),(Kazuhide Higuchi) 대한소화기학회 1999 SIDDS Vol.5 No.-

The aim of this paper is to review recent data pertaining to mechanisms of ulcer recurrence. Production of inflammatory cytokines is stimulated by ulcerogenic factors such as stress as well as NSAIDs and H. pylori infection. Therefore, the cytokines may be a common key factor to cause ulcer recurrence. When interleukin-1beta or tumor necrosis factor-alpha is administered to rats with healed chronic gastric ulcer, the ulcer recurs at the same site of previous ulcer (ulcer scar site) like most of human peptic ulcers. Excessive macrophages exist at the regenerated mucosa of ulcer scar site compared with normal mucosa adjacent to the site. Monocytes/macrophages are the major cell type responsible for production of inflammatory cytokines that activate leukocytes and stimulate expression of adhesion molecules. Therefore, the accumulation of such cells at the ulcer scar may explain why ulcers tend to recur usually at the same site. Neutrophils may contribute to the final step of recurrence of ulcer because antibody against neutrophils completely inhibits the recurrence caused by IL-1beta. Two possibly mechanisms are concerned: their cytotoxic effects to the mucosal cells via production of active oxygen species, elastase, and TNF-alpha, and microcirculatory disturbance due to neutrophil-endothelial cell interaction.

Single-Phase Heat Transfer of R245fa + Lubricant Oil Mixtures Inside Horizontal Smooth and Microfin Tubes

Daisuke Jige,Yufei Liu,KAZUHIDE WATANABE,Norihiro Inoue 대한설비공학회 2019 International Journal Of Air-Conditioning and Refr Vol.27 No.2

The effect of lubricant oil on the single-phase heat transfer of R245fa inside horizontal smooth and microfin tubes was experimentally investigated. Tests were conducted using a horizontal smooth tube with an inner diameter of 8.32 mm and two microfin tubes with equivalent diameters of 8.9 and 8.7 mm, fin height of 0.12 and 0.18 mm, and number of fins of 65 and 85, respectively. The heat transfer coefficients were measured for pure R245fa and R245fa + lubricant oil mixture in the Reynolds number range of 2000–10000, heat fluxes of 5 and 10 kWm −2, and refrigerant temperatures of 30∘C and 45∘C at the test section inlet. Oil concentration was varied at 1, 2 and 5 wt.%. The results showed that the heat transfer of pure R245fa agreed well with previous correlations. However, the heat transfer coefficients of the R245fa + lubricant oil mixtures were lower than those of the pure R245fa, and decreased with an increase in oil concentration for both smooth and microfin tubes. The reduction in heat transfer was more marked for the HF tube than for the smooth and LF tubes. For the HF tube, the decrease in heat transfer was apparently more pronounced at higher oil concentrations from 2 to 5 wt.% owing to immiscibility between the oil and refrigerant.

PRESSURE DROP AND HEAT TRANSFER INSIDE THE COILED FLOW CHANNEL OF SMOOTH TUBES AND INTERNALLY HELICAL-GROOVED TUBES

NORIHIRO INOUE,SHINITSU IKU,KAZUHIDE WATANABE 대한설비공학회 2012 International Journal Of Air-Conditioning and Refr Vol.20 No.4

In this study, we investigated ways of improving the performance of heat exchangers, which are the heat pumps for use in hot-water supply systems on the hot-water supply side. Therefore, we verified experimentally the pressure drop and the heat transfer characteristics within the coiled flow channel. Five smooth copper tubes and five internally helical-grooved copper tubes with an outside diameter of 12.7mm and coil diameters of 100 mm, 120 mm, 140 mm, 160mm and 180mm were used as the heat-transfer coiled tubes in the experiments. Experiments were conducted under conditions of constant isothermal heating and fluid flow inside coiled tubes with an inlet temperature of 20℃, and the flow rates of the fluid flow inside the coiled tubes were adjusted and varied to change the Reynolds number within the range of 900 to 25,000. Based on the experimental values, we proposed prediction equations to systematically calculate the friction factor and the heat transfer coefficient for different curvature radius ratios.

Gelation of Solvate Ionic Liquid by Self-Assembly of Block Copolymer and Characterization as Polymer Electrolyte

Kitazawa, Yuzo,Iwata, Kaori,Imaizumi, Satoru,Ahn, Hyungmin,Kim, Sung Yeon,Ueno, Kazuhide,Park, Moon Jeong,Watanabe, Masayoshi American Chemical Society 2014 Macromolecules Vol.47 No.17

<P>We report a new class of polymer electrolytes that exhibit high Li<SUP>+</SUP>-ionic conductivity and thermal stability up to 200 °C. The polymer electrolyte consists of a solvate ionic liquid ([Li(G4)][TFSA]), comprising an equimolar mixture of lithium bis(trifluoromethanesulfonyl)amide (Li[TFSA]) and tetraglyme (G4), and a well-defined ABA-triblock copolymer, polystyrene-<I>b</I>-poly(methyl methacrylate)-<I>b</I>-polystyrene (PSt-<I>b</I>-PMMA-<I>b</I>-PSt, SMS). The electrolyte is formed by the self-assembly of SMS, where the solvatophobic PSt segments serves as physical cross-linking points, and the solvatophilic PMMA segment with preferentially dissolved [Li(G4)][TFSA] forms ion-conduction paths. In the electrolyte, the preservation of the complex cation [Li(G4)]<SUP>+</SUP> in the PMMA phase was demonstrated by pulsed-field gradient spin–echo (PGSE) NMR, Raman spectra, and thermogravimetric analysis. Because of the preservation of [Li(G4)]<SUP>+</SUP>, which hinders the direct interaction of Li<SUP>+</SUP> with the polymer segment and the coupling of the ionic transport from the segmental motion, the room temperature ionic conductivity of the electrolyte reached an appreciable level (10<SUP>–4</SUP>–10<SUP>–3</SUP> S cm<SUP>–1</SUP>).</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/mamobx/2014/mamobx.2014.47.issue-17/ma501296m/production/images/medium/ma-2014-01296m_0011.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ma501296m'>ACS Electronic Supporting Info</A></P>

Chelate Effects in Glyme/Lithium Bis(trifluoromethanesulfonyl)amide Solvate Ionic Liquids, Part 2: Importance of Solvate-Structure Stability for Electrolytes of Lithium Batteries

Zhang, Ce,Yamazaki, Azusa,Murai, Junichi,Park, Jun-Woo,Mandai, Toshihiko,Ueno, Kazuhide,Dokko, Kaoru,Watanabe, Masayoshi American Chemical Society 2014 The Journal of Physical Chemistry Part C Vol.118 No.31

<P>Highly concentrated, molten mixtures of lithium bis(trifluoromethanesulfonyl)amide (Li[TFSA]) and ether solvents (tetrahydrofuran (THF), monoglyme (G1), diglyme (G2), and triglyme (G3)) were investigated as electrolytes for Li batteries. To compare the electrochemical reactions in the electrolytes with different solvents, the ratio of ether–oxygen atoms and Li<SUP>+</SUP> ([O]/[Li]) in the electrolytes was fixed at four. The capacity of a Li–LiCoO<SUB>2</SUB> cell with [Li(THF)<SUB>4</SUB>][TFSA] dramatically decreased upon charge/discharge cycling, whereas [Li(G3)<SUB>1</SUB>][TFSA] allowed the cell to have a stable charge–discharge cycles and a Coulombic efficiency of greater than 99% over 100 cycles. Corrosion of the Al current collector of the cathode was also affected by the composition of the electrolytes. Persistent Al corrosion took place in [Li(THF)<SUB>4</SUB>][TFSA] and [Li(G1)<SUB>2</SUB>][TFSA], which contain shorter ethers, but the corrosion was effectively suppressed in [Li(G3)<SUB>1</SUB>][TFSA]. Furthermore, lithium polysulfides, which are formed as discharge intermediates at the sulfur cathode of the Li–S cell, were much less soluble in electrolytes with longer ethers. Therefore, a higher Coulombic efficiency and more stable cycle ability were achieved in Li–S cells with [Li(G3)<SUB>1</SUB>][TFSA]. All the electrochemical properties in the batteries were dominated by the presence or absence of uncoordinating solvents in the concentrated electrolytes. This paper demonstrates that the structural stability of [Li(glyme or THF)<SUB><I>x</I></SUB>]<SUP>+</SUP> cations in electrolytes plays an important role in the performance of Li batteries.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2014/jpccck.2014.118.issue-31/jp504099q/production/images/medium/jp-2014-04099q_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp504099q'>ACS Electronic Supporting Info</A></P>

Usefulness of Simultaneous Magnetic Resonance Neurography and Apparent T2 Mapping for the Diagnosis of Cervical Radiculopathy

Enomoto Keigo,Eguchi Yawara,Sato Takashi,Norimoto Masaki,Inoue Masahiro,Watanabe Atsuya,Sakai Takayuki,Yoneyama Masami,Aoki Yasuchika,Orita Sumihisa,Narita Miyako,Inage Kazuhide,Shiga Yasuhiro,Umimura 대한척추외과학회 2022 Asian Spine Journal Vol.16 No.1

Study Design: Retrospective observational study.Purpose: We investigated the correlation between T2 relaxation times and clinical symptoms in patients with cervical radiculopathy caused by cervical disk herniation.Overview of Literature: There are currently no imaging modalities that can assess the affected cervical nerve roots quantitatively.Methods: A total of 14 patients with unilateral radicular symptoms and five healthy subjects were subjected to simultaneous apparent T2 mapping and neurography with nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation enhancement signaling (SHINKEI-Quant) using a 3-Tesla magnetic resonance imaging. The Visual Analog Scale (VAS) score for neck pain and upper arm pain was used to evaluate clinical symptoms. T2 relaxation times of the cervical dorsal root ganglia of the brachial plexus were measured bilaterally from C4 to C8 in patients with radicular symptoms and from C5 to C8 in healthy controls. The T2 ratio was calculated as the affected side to unaffected side.Results: When comparing nerve roots bilaterally at each spinal level, no significant differences in T2 relaxation times were found between patients and healthy subjects. However, T2 relaxation times of nerve roots in the patients with unilateral radicular symptoms were significantly prolonged on the involved side compared with the uninvolved side (p<0.05). The VAS score for upper arm pain was not significantly correlated with the T2 relaxation times, but was positively correlated with the T2 ratio.Conclusions: In patients with cervical radiculopathy, the SHINKEI-Quant technique can be used to quantitatively evaluate the compressed cervical nerve roots. The VAS score for upper arm pain was positively correlated with the T2 ratio. This suggests that the SHINKEI-Quant is a potential tool for the diagnosis of cervical nerve entrapment.

Dry deposition of nitric acid gas by long‑term measurement above and below a forest canopy

Zhaojie Wu,Mao Xu,Atsuyuki Sorimachi,Hiroyuki Sase,Makoto Watanabe,Kazuhide Matsuda 한국대기환경학회 2024 Asian Journal of Atmospheric Environment (AJAE) Vol.18 No.1

Reactive nitrogen negatively affects terrestrial ecosystems by excessive deposition. Nitric acid gas ( HNO3), a component of reactive nitrogen, is readily deposited on ground surfaces due to its high reactivity. However, there have been recent cases in which suppressed deposition fluxes, including upward fluxes, were observed above forests. As the mechanisms of HNO3 dry deposition on forest surfaces are not fully understood, the accuracy of dry deposition estimates remains uncertain. To reduce uncertainties in the estimation, we investigated dry deposition of HNO3 by 1-year measurement in a forest. We measured the vertical profiles of HNO3, nitrate, and sulfate in PM2.5 in a deciduous forest in suburban Tokyo (FM Tama). We observed their concentrations above the forest canopy (30 m) and near the forest floor (2 and 0.2 m) using the denuder/filter pack from October 2020 to September 2021. The HNO3 concentration decreased significantly from 30 to 2 m. However, the decrease in HNO3 was not as significant, and occasionally, emission profiles were produced between 2 and 0.2 m. This was likely caused by HNO3 generated by the volatilization of NH4NO3 near the forest floor, which was warmed by sunlight during daytime in both leafy and leafless periods. Conversely, HNO3 concentrations at 30 m were much higher than those at 2 m and 0.2 m, indicating that the forest acted as a sink for HNO3 from a long-term perspective. It is presumed that HNO3, generated just above the forest canopy, could cause an upward flux if a temperature difference of several degrees occurs between 25 and 20 m.

Solvate Ionic Liquid Electrolyte for Li–S Batteries

Dokko, Kaoru,Tachikawa, Naoki,Yamauchi, Kento,Tsuchiya, Mizuho,Yamazaki, Azusa,Takashima, Eriko,Park, Jun-Woo,Ueno, Kazuhide,Seki, Shiro,Serizawa, Nobuyuki,Watanabe, Masayoshi The Electrochemical Society 2013 Journal of the Electrochemical Society Vol.160 No.8

<P>Innovation in the design of electrolyte materials is crucial for realizing next-generation electrochemical energy storage devices such as Li–S batteries. The theoretical capacity of the S cathode is 10 times higher than that of conventional cathode materials used in current Li–ion batteries. However, Li–S batteries suffer from the dissolution of lithium polysulfides, which are formed by the redox reaction at the S cathode. Herein, we present simple solvate ionic liquids, glyme–Li salt molten complexes, as excellent electrolyte candidates because they greatly suppress the dissolution of lithium polysulfides. The molten complexes do not readily dissolve other ionic solutes, which leads to the stable operation of the Li–S battery over more than 400 cycles with discharge capacities higher than 700 mAh g-sulfur<SUP>−1</SUP> and with coulombic efficiencies higher than 98% throughout the cycles. Such high performance has not been realized to the best of our knowledge. Furthermore, the addition of a nonflammable fluorinated solvent, which does not break the solvate structure of the glyme–Li salt molten complexes, greatly enhances the power density of the Li–S battery. The strategic design of electrolyte properties provides opportunities for the development of new electrochemical devices with many different electrode materials.</P>