A brief review of the ionic conductivity enhancement for selected oxide electrolytes

The advantages of lowering the operation temperature of SOFCs have attracted great interest worldwide. One of the major barriers to decreasing the operation temperature is the ohmic loss of the electrolyte. Maximizing the electrolyte ionic conductivity is of significant importance, especially in the absence of new electrolyte materials. The ionic conductivity of electrolytes can be influenced by many parameters. There has been an enormous effort in the literature for the improvement of the electrolyte ionic conductivity. From a practical point of view, this paper reviews various approaches to enhancing the ionic conductivity of polycrystalline zirconia- and ceria-based oxide electrolytes in the light of composition, microstructure, and processing. Suggestions are given for future work.     

Dysprosium doped copper oxide (Cu1-xDyxO) nanoparticles enabled bifunctional electrode for overall water splitting

The production of hydrogen, a favourable alternative to an unsustainable fossil fuel remains as a significant hurdle with the pertaining challenge in the design of proficient, highly productive and sustainable electrocatalyst for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, the dysprosium (Dy) doped copper oxide (Cu_1-xDy_xO) nanoparticles were synthesized via solution combustion technique and utilized as a non-noble metal based bi-functional electrocatalyst for overall water splitting. Due to the improved surface to volume ratio and conductivity, the optimized Cu_1-xDy_xO (x = 0.01, 0.02) electrocatalysts exhibited impressive HER and OER performance respectively in 1 M KOH delivering a current density of 10 mAcm^?2 at a potential of ?0.18 V vs RHE for HER and 1.53 V vs RHE for OER. Moreover, the Dy doped CuO electrocatalyst used as a bi-functional catalyst for overall water splitting achieved a potential of 1.56 V at a current density 10 mAcm^?2 and relatively high current density of 66 mAcm^?2 at a peak potential of 2 V. A long term stability of 24 h was achieved for a cell voltage of 2.2 V at a constant current density of 30 mAcm^?2 with only 10% of the initial current loss. This showcases the accumulative opportunity of dysprosium as a dopant in CuO nanoparticles for fabricating a highly effective and low-cost bi-functional electrocatalyst for overall water splitting.     

穿越黑色时空的光影世界——间离剧

正一家在上海创办的建筑与室内设计事务所,致力于根据客户的需求制定美观新颖的空间解决方案。我们对概念的艺术性和施工的工艺同样重视。每个项目都根据其环境和条件量身定做,并在有限的造价和时间里做出最好的效果。来到这个剧院的观众,都是自己这出戏的演员和导演。间离剧以独特的形态,为观众提供了别具一格     

Pinecone biomass-derived activated carbon: the potential electrode material for the development of symmetric and asymmetric supercapacitors

Activated carbon, from biomass (pinecone), was synthesized by conventional pyrolysis/chemical activation process and utilized for the fabrication of supercapacitor electrodes. The pinecone-activated carbon synthesized with 1:4 ratio of KOH (PAC4) showed an increase in surface area and pore density with a considerable amount of oxygen functionalities on the surface. Moreover, PAC4, as supercapacitor electrode, exhibited excellent electrochemical performances with specific capacitance value ∼185 Fg⁻¹ in 1 M H₂SO₄, which is higher than that of nonactivated pinecone carbon and 1:2 ratio KOH-based activated carbon (PAC2) (∼144 Fg⁻¹). The systematic studies were performed to design various forms of devices (symmetric and asymmetric) to investigate the effect of device architecture and operating voltage on the performance and stability of the supercapacitors. The symmetric supercapacitor, designed utilizing PAC4 in H₂SO₄ electrolyte, exhibited a maximum device-specific capacitance of 43 Fg⁻¹ with comparable specific energy/power and excellent stability (∼96% after 10 000 cycles). Moreover, a symmetric supercapacitor was specially designed using PAC4, as a positive electrode, and PAC2, as a negative electrode, under their electrolytic ion affinity, and which operates in aqueous Na₂SO₄ electrolyte for a wide cell voltage (1.8 V) and showed excellent supercapacitance performances. Also, a device was assembled with poly(3,4-ethylene dioxythiophene) (PEDOT) nanostructure, as positive electrode, and PAC4, as a negative electrode, to evaluate the feasibility of designing a hybrid supercapacitor, using polymeric nanostructure, as an electrode material along with biomass-activated carbon electrode.     

Cell-free Stem Cell-Derived Extract Formulation for Regenerative Medicine Applications

Stem cells for regenerative medicine purposes offer therapeutic benefits, but disadvantages are still ill defined. The benefit of stem cells may be attributed to their secretion of growth factors (GFs), cytokines (CKs), and extracellular vesicles (EVs), including exosomes. We present a novel cell-free stem cell-derived extract (CCM), formulated from human progenitor endothelial stem cells (hPESCs), characterized for biologically active factors using ELISA, nanoparticle tracking analysis and single particle interferometric reflectance imaging sensing. The effect on fibroblast proliferation and ability to induce stem cell migration was analyzed using Alamar Blue proliferation and Transwell migration assays, respectively. GFs including IGFBP 1, 2, 3, and 6, insulin, growth hormone, PDGF-AA, TGF-α, TGF-β1, VEGF, and the anti-inflammatory cytokine, IL-1RA were detected. Membrane enclosed particles within exosome size range and expressing exosome tetraspanins CD81 and CD9 were identified. CCM significantly increased cell proliferation and induced stem cell migration. Analysis of CCM revealed presence of GFs, CKs, and EVs, including exosomes. The presence of multiple factors including exosomes within one formulation, the ability to promote cell proliferation and induce stem cell migration may reduce inflammation and pain, and augment tissue repair.     

Bend,Twist, and Turn: First Bendable and Malleable Toughened PLA Green Composites

The future of green electronics possessing great strength and toughness proves to be a promising area of research in this technologically advanced society. This work develops the first fully bendable and malleable toughened polylactic acid (PLA) green composite by incorporating a multifunctional polyhydroxybutyrate rubber copolymer filler that acts as an effective nucleating agent to accelerate PLA crystallization and performs as a dynamic plasticizer to generate massive polymer chain movement. The resultant biocomposite exhibits a 24‐fold and 15‐fold increment in both elongation and toughness, respectively, while retaining its elastic modulus at >3 GPa. Mechanism studies show the toughening effect is due to an amalgamation of massive shear yielding, crazing, and nanocavitation in the highly dense PLA matrix. Uniquely distinguished from the typical flexible polymer that stretches and recovers, this biocomposite is the first report of PLA that can be “bend, twist, turn, and fold” at room temperature and exhibit excellent mechanical robustness even after a 180° bend, attributes to the highly interconnected polymer network of innumerable nanocavitation complemented with an extensively unified fibrillar bridge. This unique trait certainly opens up a new horizon to future sustainable green electronics development.     

Thermal conductivity measurement of erythritol,xylitol, and their blends for phase change material design: A methodological study

This work presents and discusses a detailed thermal conductivity assessment of erythritol, xylitol, and their blends: 25 mol% erythritol and 80 mol% erythritol using the transient plane source (TPS) method with a Hot Disk Thermal Constants Analyzer TPS‐2500S. Thereby, the thermal conductivities of xylitol, 25 mol% erythritol, 80 mol% erythritol, and erythritol were here found for respectively in the solid state to be 0.373, 0.394, 0.535, and 0.589 W m^?1 K^?1 and in the liquid state to be 0.433, 0.402, 0.363, and 0.321 W m^?1 K^?1. These obtained results are comprehensively and critically analyzed as compared to available literature data on the same materials, in the phase change materials (PCMs) design context. This study clearly indicates that these thermal conductivity data in literature have considerable discrepancies between the literature sources and as compared to the data obtained in the present investigation. Primary reasons for these disparities are identified here as the lack of sufficiently transparent and repeatable data and procedure reporting, and relevant standards in this context. To exemplify the significance of such transparent and repeatable data reporting in thermal conductivity evaluations in the PCM design context, here focused on the TPS method, a comprehensive measurement validation is discussed along various residual plots obtained for varying input parameters (ie, the heating power and time). Clearly, the variations in the input parameters give rise to various thermal conductivity results, where choosing the most coherent result requires a sequence of efforts per material, because there are no universally valid conditions. Transparent and repeatable data and procedure reporting are the key to achieve comparable thermal conductivity results, which are essential for the correct design of thermal energy storage systems using PCMs.     

Geochemical modulation of pesticide sorption on smectite clay

Pesticide adsorption by soil clays can be dramatically influenced by the exchangeable cations present. Among the common exchangeable base cations in soils (Ca2+, Mg2+, K+, and Na+), K+-saturated clays frequently demonstrate the strongest affinity for pesticides. In the presence of multiple exchangeable cations in the system, we hypothesize that the magnitude of pesticide sorption to soil minerals is proportional to the fraction of clay interlayers saturated with K+ ions. To test this hypothesis, we measured sorption of three pesticides with different polarities (dichlobenil, monuron, and biphenyl) by homoionic K- and Ca-smectite (SWy-2) in KCl/CaCl2 aqueous solutions. The presence of different amounts of KCl and CaCl2 resulted in varying populations of K+ and Ca2+ on the clay exchange sites. The sorption of dichlobenil and, to a lesser extent monuron, increased with the fraction of K+ on clay mineral exchange sites. Ca- and K-SWy-2 displayed the same sorption capacities for nonpolar biphenyl. X-ray diffraction patterns indicated that at lower fractions of K+-saturation, exchangeable K+ ions were randomly distributed in clay interlayers and did not enhance pesticide sorption. At higher populations of K+ (vs Ca2+), demixing occurred causing some clay interlayers, regions, or tactoids to become fully saturated by K+, manifesting greatly enhanced pesticide sorption. The forward and reverse cation exchange reactions influenced not only K+ and Ca2+ populations on clays but also the nanostructures of clay quasicrystals in aqueous solution which plays an important, if not dominant, role in controlling the extent of pesticide sorption. Modulating the cation type and composition on clay mineral surfaces through cation exchange processes provides an environmental-safe protocol to manipulate the mobility and availability of polar pesticides, which could have applications for pesticide formulation and in environmental remediation.     

Polybrominated diphenyl ethers in the sediments of the Great Lakes. 3. Lakes Ontario and Erie

Sediment cores were taken in 2002 in Lakes Ontario and Erie at four locations. A total of 48 sediment samples were characterized, dated using 210Pb, and analyzed for 10 congeners of polybrominated diphenyl ethers (PBDEs) including BDE209 as well as 39 congeners of polychlorinated biphenyls (PCBs). The surficial concentrations of nine tri- through hepta-BDE congeners (sigma9PBDE) are 4.85 and 6.33 ng g(-1), at sampling sites ON40 and ON30 in Lake Ontario, and 1.83 and 1.95 ng g(-1) at ER37 and ER09 in Lake Erie, respectively, based on dry sediment weight. The surficial BDE209 concentrations are 242 and 211 ng g(-1) at ON40 and ON30 and 50 and 55 ng g(-1) at ER37 and ER09. The sigma(9-) PBDEs fluxes to the sediment around 2002 are 147 and 195 pg cm(-2) year(-1) at ON40 and ON30 and 136 and 314 pg cm(-2) year(-1) at ER37 and ER09, respectively. The fluxes of BDE209 are 6.5 and 7.3 ng cm(-2) year(-1) at ON30 and ON40 and 3.7 and 8.9 ng cm(-2) year(-1) at ER37 and ER09, respectively. Dramatic increases in PBDE concentrations and fluxes upward toward the sediment surface and the present time are evident at both locations in Lake Ontario, while PCBs concentrations peak in the middle of sediment cores around the dated time of 1970s and 1960s. For both locations of Lake Erie, the increasing trends of both PBDEs and PCBs from the bottom to the surficial segments were distorted by sediment mixing. BDE209 is the most abundant congener among PBDEs in the sediments, constituting about 96 and 91% of the total PBDEs on mass basis in Lakes Ontario and Erie, respectively.