Bismuth Oxychloride/MXene symmetric supercapacitor with high volumetric energy density

Xia, Qi Xun,Shinde, Nanasaheb M.,Yun, Je Moon,Zhang, Tengfei,Mane, Rajaram S.,Mathur, Sanjay,Kim, Kwang Ho Elsevier 2018 ELECTROCHIMICA ACTA Vol.271 No.-

<P><B>Abstract</B></P> <P>Since the discovery of two-dimensional (2D) graphene, a new class of 2D materials with excellent electrical conductivity has recently been attracting attention in studying promising electrode materials in energy storage applications. Herein, bismuth oxychloride nanosheets-immobilised Ti<SUB>3</SUB>C<SUB>2</SUB>T<SUB>x</SUB> MXene material (TCBOC) is synthesised by a facile and cost-effective chemical bath deposition (CBD) route. The bismuth oxychloride (BiOCl) nanosheets are grown and immobilised on surfaces of Ti<SUB>3</SUB>C<SUB>2</SUB>T<SUB>x</SUB>-MXene flakes. An electrode based on the TCBOC nanocomposite exhibited a remarkably volumetric specific capacitance of 396.5 F cm<SUP>-3</SUP> at 1 A g<SUP>−1</SUP> and 228.0 F cm<SUP>-3</SUP> at 15 A g<SUP>−1</SUP>. Furthermore, a symmetric supercapacitor (SSC) assembled using TCBOC material proves to have a high energy density of 15.2 Wh kg<SUP>−1</SUP> at a power density of 567.4 W kg<SUP>−1</SUP> compared to SSCs using previously reported Ti<SUB>3</SUB>C<SUB>2</SUB>T<SUB>x</SUB> MXene materials. The SSC shows cycle life retention of 85.0% after 5000 cycles (at 5 A g<SUP>−1</SUP>). The enhanced capacitive performance is attributed to the increased surface area due to BiOCl nanosheets anchored on a 2D MXene surface, the activities of BiOCl sheets, and the excellent conductivity of a Ti<SUB>3</SUB>C<SUB>2</SUB>T<SUB>x</SUB> MXene material.</P>

Seawater electrolyte-mediated high volumetric MXene-based electrochemical symmetric supercapacitors

Xia, Qi Xun,Shinde, Nanasaheb M.,Zhang, Tengfei,Yun, Je Moon,Zhou, Aiguo,Mane, Rajaram S.,Mathur, Sanjay,Kim, Kwang Ho The Royal Society of Chemistry 2018 Dalton Transactions Vol.47 No.26

<P>The structure and morphology of titanium carbide (Ti3C2Tx) MXene, a new class of two dimensional (2D) materials, are investigated and reported. Ti3AlC2 MAX, treated with a hydrofluoric acid etching process, is used as a promising electrode material for electrochemical supercapacitor studies. The electrochemical supercapacitor performance of Ti3C2Tx as a negatrode in a natural seawater electrolyte solution, tested in a three-electrode system, demonstrated a specific capacitance of 67.7 F g<SUP>−1</SUP> at a current density of 1 A g<SUP>−1</SUP> which is in accordance with the volumetric specific capacitance of 121.8 F cm<SUP>−3</SUP>. A symmetric supercapacitor assembled with a Ti3C2Tx//Ti3C2Tx electrode configuration revealed a volumetric specific capacitance of 27.4 F cm<SUP>−3</SUP> at 0.25 A g<SUP>−1</SUP>, and 96.6% capacitance retention even after 5000 cycles, which is superior to those reported previously in similar systems, suggesting the importance of abundant and cost-effective seawater as a natural electrolyte in developing energy storage devices.</P>

Facile synthesis of manganese carbonate quantum dots/Ni(HCO₃)₂–MnCO₃ composites as advanced cathode materials for high energy density asymmetric supercapacitors

Xia, Qi Xun,San Hui, Kwan,Hui, Kwun Nam,Kim, Sung Dae,Lim, Jae Hong,Choi, Si Young,Zhang, Luo Jiang,Mane, Rajaram S.,Yun, Je Moon,Kim, Kwang Ho The Royal Society of Chemistry 2015 Journal of Materials Chemistry A Vol.3 No.44

<▼1><P>Well dispersed MnCO3 quantum dots (∼1.2 nm) decorated on Ni(HCO3)2–MnCO3 as a cathode electrode for high performance supercapacitors.</P></▼1><▼2><P>We have developed a high performance supercapacitor cathode electrode composed of well dispersed MnCO3 quantum dots (QDs, ∼1.2 nm) decorated on nickel hydrogen carbonate–manganese carbonate (Ni(HCO3)2–MnCO3) hedgehog-like shell@needle (MnCO3 QDs/NiH–Mn–CO3) composites directly grown onto a 3D macro-porous nickel foam as a binder-free supercapacitor electrode by a facile and scalable hydrothermal method. The MnCO3 QDs/NiH–Mn–CO3 composite electrode exhibited a remarkable maximum specific capacitance of 2641.3 F g<SUP>−1</SUP> at 3 A g<SUP>−1</SUP> and 1493.3 F g<SUP>−1</SUP> at 15 A g<SUP>−1</SUP>. Moreover, the asymmetric supercapacitor with MnCO3 QDs/NiH–Mn–CO3 composites as the positive electrode and graphene as the negative electrode showed an energy density of 58.1 W h kg<SUP>−1</SUP> at a power density of 900 W kg<SUP>−1</SUP> as well as excellent cycling stability with 91.3% retention after 10 000 cycles, which exceeded the energy densities of most previously reported nickel or manganese oxide/hydroxide-based asymmetric supercapacitors. The ultrahigh capacitive performance is attributed to the presence of the high surface area core–shell nanostructure, the well dispersed MnCO3 quantum dots, and the high conductivity of MnCO3 quantum dots as well as the synergetic effect between multiple transition metal ions. The superior supercapacitive performance of the MnCO3 QDs/NiH–Mn–CO3 composites makes them promising cathode materials for high energy density asymmetric supercapacitors.</P></▼2>

Provably Secure Aggregate Signcryption Scheme

Xun-Yi Ren,Zheng-Hua Qi,Yang Geng 한국전자통신연구원 2012 ETRI Journal Vol.34 No.3

An aggregate signature scheme is a digital signature scheme that allows aggregation of n distinct signatures by n distinct users on n distinct messages. In this paper, we present an aggregate signcryption scheme (ASC) that is useful for reducing the size of certification chains (by aggregating all signatures in the chain) and for reducing message size in secure routing protocols. The new ASC scheme combines identity-based encryption and the aggregation of signatures in a practical way that can simultaneously satisfy the security requirements for confidentiality and authentication. We formally prove the security of the new scheme in a random oracle model with respect to security properties IND-CCA2, AUTH-CMA2,and EUF-CMA.

NMAAP1 Expressed in BCG-Activated Macrophage Promotes M1 Macrophage Polarization

Qihui Liu,Xun Zhu,Yuan Tian,Xiangfeng Zhao,Haifeng Jing,Qi Xie,Peng Li,Dong Li,Dongmei Yan 한국분자세포생물학회 2015 Molecules and cells Vol.38 No.10

Macrophages are divided into two subpopulations: classically activated macrophages (M1) and alternatively activated macrophages (M2). BCG (Bacilli Calmette-Guérin) activates disabled naïve macrophages to M1 macrophages, which act as inflammatory, microbicidal and tumoricidal cells through cell-cell contact and/or the release of soluble factors. Various transcription factors and signaling pathways are involved in the regulation of macrophage activation and polarization. We discovered that BCG-activated macrophages (BAM) expressed a new molecule, and we named it Novel Macrophage Activated Associated Protein 1 (NMAAP1). 1 The current study found that the overexpression of NMAAP1 in macrophages results in M1 polarization with increased expression levels of M1 genes, such as inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-α), Interleukin 6 (IL-6), Interleukin 12 (IL-12), Monocyte chemoattractant protein-1 (MCP-1) and Interleukin-1 beta (IL-1β), and decreased expression of some M2 genes, such as Kruppel-like factor 4 (KLF4) and suppressor of cytokine signaling 1 (SOCS1), but not other M2 genes, including arginase-1 (Arg-1), Interleukin (IL-10), transforming growth factor beta (TGF-β) and found in inflammatory zone 1 (Fizz1). Moreover, NMAAP1 overexpression in the RAW264.7 cell line increased cytotoxicity against MCA207 tumor cells, which depends on increased inflammatory cytokines rather than cell-cell contact. NMAAP1 also substantially enhanced the phagocytic ability of macrophages, which implies that NMAAP1 promoted macrophage adhesive and clearance activities. Our results indicate that NMAAP1 is an essential molecule that modulates macrophages phenotype and plays an important role in macrophage tumoricidal functions.

Feasibility of Free-Breathing, Non-ECG-Gated, Black-Blood Cine Magnetic Resonance Images With Multitasking in Measuring Left Ventricular Function Indices

Peng Pengfei,Yue Xun,Tang Lu,Wu Xi,Deng Qiao,Wu Tao,Cai Lei,Liu Qi,Xu Jian,Huang Xiaoqi,Chen Yucheng,Diao Kaiyue,Sun Jiayu 대한영상의학회 2023 Korean Journal of Radiology Vol.24 No.12

Objective: To clinically validate the feasibility and accuracy of cine images acquired through the multitasking method, with no electrocardiogram gating and free-breathing, in measuring left ventricular (LV) function indices by comparing them with those acquired through the balanced steady-state free precession (bSSFP) method, with multiple breath-holds and electrocardiogram gating. Materials and Methods: Forty-three healthy volunteers (female:male, 30:13; mean age, 23.1 ± 2.3 years) and 36 patients requiring an assessment of LV function for various clinical indications (female:male, 22:14; 57.8 ± 11.3 years) were enrolled in this prospective study. Each participant underwent cardiac magnetic resonance imaging (MRI) using the multiple breath-hold bSSFP method and free-breathing multitasking method. LV function parameters were measured for both MRI methods. Image quality was assessed through subjective image quality scores (1 to 5) and calculation of the contrast-to-noise ratio (CNR) between the myocardium and blood pool. Differences between the two MRI methods were analyzed using the Bland–Altman plot, paired t-test, or Wilcoxon signed-rank test, as appropriate. Results: LV ejection fraction (LVEF) was not significantly different between the two MRI methods (P = 0.222 in healthy volunteers and P = 0.343 in patients). LV end-diastolic mass was slightly overestimated with multitasking in both healthy volunteers (multitasking vs. bSSFP, 60.5 ± 10.7 g vs. 58.0 ± 10.4 g, respectively; P < 0.001) and patients (69.4 ± 18.1 g vs. 66.8 ± 18.0 g, respectively; P = 0.003). Acceptable and comparable image quality was achieved for both MRI methods (multitasking vs. bSSFP, 4.5 ± 0.7 vs. 4.6 ± 0.6, respectively; P = 0.203). The CNR between the myocardium and blood pool showed no significant differences between the two MRI methods (18.89 ± 6.65 vs. 18.19 ± 5.83, respectively; P = 0.480). Conclusion: Multitasking-derived cine images obtained without electrocardiogram gating and breath-holding achieved similar image quality and accurate quantification of LVEF in healthy volunteers and patients.

Direct successive ionic layer adsorption and reaction (SILAR) synthesis of nickel and cobalt hydroxide composites for supercapacitor applications

Lee, Damin,Xia, Qi Xun,Mane, Rajaram S.,Yun, Je Moon,Kim, Kwang Ho ELSEVIER SCIENCE 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.722 No.-

<P><B>Abstract</B></P> <P>Mesoporous nickel and cobalt hydroxide composites are directly grown onto 3D macro-porous Ni foam as a binder-free electrode for supercapacitors by using the successive ionic layer adsorption and reaction (SILAR) method. This method is the cheapest and simplest among several deposition processes for supercapacitor applications. An as-obtained porous NiCo(OH)<SUB>2</SUB> electrode exhibits a remarkable specific capacity (1113.6 mAh g<SUP>−1</SUP> at a current density of 3 A g<SUP>−1</SUP>) and excellent cycling stability (85.62% capacity retention after 5000 cycles). Furthermore, an asymmetric supercapacitor assembled with NiCo(OH)<SUB>2</SUB> as a positive electrode and graphene as a negative electrode shows a high energy density of 20.07 W h kg<SUP>−1</SUP> at a power density of 2302.73 W kg<SUP>−1</SUP> and excellent cycling stability (76.46% retention after 5000 cycles). As a result, it shows that the NiCo(OH)<SUB>2</SUB> fabricated by the SILAR method can be a promising electrode towards energy-storage devices with high energy and power densities.</P> <P><B>Highlights</B></P> <P> <UL> <LI> SILAR method is a process conducted under mild conditions for 30 s. </LI> <LI> NiCo(OH)<SUB>2</SUB> composite by SILAR method is a 3D flower-like porous nanostructure. </LI> <LI> The synthesized NiCo(OH)<SUB>2</SUB> electrode shows high electrochemical performances. </LI> <LI> The specific capacity of the NiCo(OH)<SUB>2</SUB> electrode is 1113.6 mAh g<SUP>−1</SUP> at 3 A g<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Sports injury treatment and sports rehabilitation employing the Nanoparticles containing zinc oxide

Zhichao Ma,Jie Qi,Weiwei Xun,Yaonan Li Techno-Press 2023 Advances in nano research Vol.15 No.1

The combination of physical activities and individual skills in sports creates an entertaining and competitive environment governed by a set of rules. In today's world, sports attract significant attention and are approached differently by various groups. Inevitably, injuries occur in sports, significantly impacting an athlete's performance and ability to participate in exercises and competitions. Addressing this issue, one of the crucial measures involves restoring the athlete's ability to engage in sports and compete. Sports rehabilitation serves as a treatment to mitigate the effects of injuries, and when combined with surgery, it can expedite the recovery process. Therefore, the primary objective of this study is to utilize a biocompatible technology for synthesizing zinc oxide (ZnO) nanoparticles in sports rehabilitation, ensuring minimal harm to the environment.

Design and Analysis of an Active Balancing Mechanism for a Vertical Axis Washing Machine

Hai-Wei Chen,Xun-Ting Yuan,Zhen Sun,Qiu-Qi Mou,Ming Xiong,Wei-Hua Wang 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.23 No.7

In recent years, active balancing of washing machines has drawn much attention from manufactures. This paper proposes a novel active balancing mechanism for vibration suppression of a vertical axis washing machine which employs water for counteracting the unbalanced laundry. At first, a novel structure with two balancing planes sharing only one set of nozzles for injecting water is designed and the balancing capability of the structure is analyzed. Then, a dynamic model of the active balancing system is constructed. Vibration characteristics of the system including changes of the vibration amplitude and phase angle under different influences are studied. After that, a strategy for identifying the imbalance is proposed and an active control method is designed. At last, a washing machine armed with the active mechanism is manufactured. Both a fixed eccentric block and a pile of randomly distributed laundry are used to test the balancing effect. The results show that lateral vibrations of the washer can be greatly reduced by the active mechanism. Due to the simplicity of the structure and the satisfactory balancing effect, the mechanism proposed has a big potential to be employed in future washing machines.

The Epitope Recognized by Monoclonal Antibody 2B6 in the B/C Domains of Classical Swine Fever Virus Glycoprotein E2 Affects Viral Binding to Hyperimmune Sera and Replication

( Chao Tong ),( Ning Chen ),( Xun Liao ),( Wen Qi Xie ),( De Jiang Li ),( Xiao Liang Li ),( Wei Huan Fang ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.4

Classical swine fever (CSF) is a highly contagious disease of pigs caused by CSF virus (CSFV). E2 is the major viral envelope protein of immune dominance that induces neutralizing antibodies and confers protection against CSFV infection. The B/C domains of E2 are variable among CSFV isolates, which could affect immunogenicity and binding to antibodies. We attempted to characterize the epitope recognized by a monoclonal antibody 2B6 (mAb-2B6) raised against the E2 B/C domains of the vaccine C-strain and to examine if mutations in the epitope region would affect antibody binding and viral neutralization. The epitope specific for mAb-2B6 recognition is linear, spanning five residues 774DGXNP778 in the B/C domains. The residue N777 is indispensable for the specificity. The epitope exists only in group 1 strains, but not in those of group 2. The recombinant viruses containing individual mutations on the epitope region lost the reactivity to mAb-2B6. The mutant virus RecC-N777S had low replication potential, about 10-fold decrease in the yield of progeny virus particles, whereas the mutant virus RecC-P778A reverted to proline upon continuous passaging. The mutations on the mAb-2B6 epitope region did not affect neutralization by anti-C-strain polyclonal sera from pigs. Deletion from aa774 covering the mAb-2B6 epitope, but not that from aa781, also affected binding with the polyclonal antibodies from vaccinated pigs, although the major binding region for the vaccinated antibodies is aa690-773.