bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiscale Characterization and Quantification of Arsenic Mobilization and Attenuation During Injection of Treated Coal Seam Gas Coproduced Water into Deep Aquifers
Authors: Rathi Bhasker , Siade Adam J. , Donn Michael J. , Helm Lauren , Morris Ryan , Davis James A. , Berg Michael , Prommer Henning
Published: December 2017

Coal seam gas production involves generation and management of large amounts of co‐produced water. One of the most suitable methods of management is injection into deep aquifers. Field injection trials may be used to support the predictions of anticipated hydrological and geochemical impacts of injection. The present work employs reactive transport modeling (RTM) for a comprehensive analysis of data collected from a trial where arsenic mobilization was observed. Arsenic sorption behavior was studied through laboratory experiments, accompanied by the development of a surface complexation model (SCM). A field‐scale RTM that incorporated the laboratory‐derived SCM was used to simulate the data collected during the field injection trial and then to predict the long‐term fate of arsenic. We propose a new practical procedure which integrates laboratory and field‐scale models using a Monte Carlo type uncertainty analysis and alleviates a significant proportion of the computational effort required for predictive uncertainty quantification. The results illustrate that both arsenic desorption under alkaline conditions and pyrite oxidation have likely contributed to the arsenic mobilization that was observed during the field trial. The predictive simulations show that arsenic concentrations would likely remain very low if the potential for pyrite oxidation is minimized through complete deoxygenation of the injectant. The proposed modeling and predictive uncertainty quantification method can be implemented for a wide range of groundwater studies that investigate the risks of metal(loid) or radionuclide contamination.
Learning Curve for Seawater Reverse Osmosis Desalination Plants: Capital Cost Trend of the Past, Present, and Future
Authors: Caldera Upeksha , Breyer Christian
Published: December 2017

Seawater reverse osmosis (SWRO) desalination is expected to play a pivotal role in helping to secure future global water supply. While the global reliance on SWRO plants for water security increases, there is no consensus on how the capital costs of SWRO plants will vary in the future. The aim of this paper is to analyze the past trends of the SWRO capital expenditures (capex) as the historic global cumulative online SWRO capacity increases, based on the learning curve concept. The SWRO capex learning curve is found based on 4,237 plants that came online from 1977 to 2015. A learning rate of 15% is determined, implying that the SWRO capex reduced by 15% when the cumulative capacity was doubled. Based on SWRO capacity annual growth rates of 10% and 20%, by 2030, the global average capex of SWRO plants is found to fall to 1,580 USD/(m3/d) and 1,340 USD/(m3/d), respectively. A learning curve for SWRO capital costs has not been presented previously. This research highlights the potential for decrease in SWRO capex with the increase in installation of SWRO plants and the value of the learning curve approach to estimate future SWRO capex.
Microstructure and Mechanical Properties of Ti2AlNb‐Based Alloys Synthesized by Spark Plasma Sintering from Pre‐Alloyed and Ball‐Milled Powder
Authors: Li Mengchen , Cai Qi , Liu Yongchang , Ma Zongqing , Wang Zumin
Published: December 2017

Ti2AlNb‐based alloys are synthesized by spark plasma sintering from pre‐alloyed and ball‐milled Ti–22Al–25Nb powder, and the structure of the alloys is regulated by aging at 800 °C for 0.5, 1, 2, and 3 h. Comparison of phase composition, microstructure, and mechanical properties are made in this study. Aging in the B2 + O phase region refers to the reversible transformation of B2 ↔ O. Complete B2 + O Widmanstätten structure is obtained in the aged alloys synthesized from pre‐alloyed powder, and the ones from milled powder contain acicular O and B2 + O Widmanstätten structure. Ball milling eliminates the B2 + O colonies, facilitates the continuous transformation of O → B2, and induces acicular O in the alloys; however, the hardness of these alloys is decreased in contrast with that of the ones synthesized from pre‐alloyed powder. Owing to the precipitation strengthening based on a large amount of fine O‐phase precipitates, the 3 h aged alloy from pre‐alloyed powder exhibits comprehensive mechanical properties with Vickers hardness of 448 ± 9 HV, ultimate tensile strength of 730 MPa, and elongation of 0.43%.
Exosome as a Vehicle for Delivery of Membrane Protein Therapeutics, PH20, for Enhanced Tumor Penetration and Antitumor Efficacy
Authors: Hong Yeonsun , Nam Gi‐Hoon , Koh Eunee , Jeon Sangmin , Kim Gi Beom , Jeong Cherlhyun , Kim Dong‐Hwee , Yang Yoosoo , Kim In‐San
Published: December 2017

As biochemical and functional studies of membrane protein remain a challenge, there is growing interest in the application of nanotechnology to solve the difficulties of developing membrane protein therapeutics. Exosome, composed of lipid bilayer enclosed nanosized extracellular vesicles, is a successful platform for providing a native membrane composition. This study reports an enzymatic exosome, which harbors native PH20 hyaluronidase (Exo‐PH20), which is able to penetrate deeply into tumor foci via hyaluronan degradation, allowing tumor growth inhibition and increased T cell infiltration into the tumor. This exosome‐based strategy is developed to overcome the immunosuppressive and anticancer therapy‐resistant tumor microenvironment, which is characterized by an overly accumulated extracellular matrix. Notably, this engineered exosome with the native glycosylphosphatidylinositol‐anchored form of hyaluronidase has a higher enzymatic activity than a truncated form of the recombinant protein. In addition, the exosome‐mediated codelivery of PH20 hyaluronidase and a chemotherapeutic (doxorubicin) efficiently inhibits tumor growth. This exosome is designed to degrade hyaluronan, thereby augmenting nanoparticle penetration and drug diffusion. The results thus show that this is a promising exosome‐based platform that harbors not only a membrane‐associated enzyme with high activity but also therapeutic payloads.
Single‐Component‐Based White Light Photoluminescence Emission via Selective Photooxidation in an Organic–Polymer Hybrid System
Authors: Lee Minkyung , Song Intek , Hong Misun , Koo Jin Young , Choi Hee Cheul
Published: December 2017

White light‐emitting phenothiazine‐poly(dimethylsiloxane) (PTZ–PDMS) composites are formed by a photooxidation reaction. The oxidized PTZ species, i.e., PTZ cation radicals and dication species, are created by electron transfer from the PTZ molecules to PDMS under UV irradiation. In situ UV–vis and electron spin resonance (ESR) spectroscopies are carried out after UV exposure of PTZ–PDMS, and the results provide evidence for the spontaneous ionization of PTZ. The spectral changes indicate the formation of PTZ•+ (radical cation) and PTZ2+ (dication) within the PDMS matrix. Moreover, a combination of PTZ, PTZ•+, and PTZ2+, together with the PDMS matrix, show an unexpected emission of white light with Commission Internationale de L'Eclairage coordinates of 0.34 and 0.32, which are close to those of pure white light. These findings potentially offer a new route and strategy for the development of flexible white light‐emitting materials.
Hollow Mesoporous Carbon Nanocubes: Rigid‐Interface‐Induced Outward Contraction of Metal‐Organic Frameworks
Authors: Liu Chao , Huang Xiaodan , Wang Jing , Song Hao , Yang Yannan , Liu Yang , Li Jiansheng , Wang Lianjun , Yu Chengzhong
Published: December 2017

Novel carbon materials derived from metal‐organic frameworks (MOFs) have attracted much attention, but the commonly inevitable inward contraction during the carbonization process has restricted their structural variety and applications. In this work, a novel rigid‐interface induced outward contraction approach is reported for synthesizing hollow mesoporous carbon nanocubes (HMCNCs) by using ZIF‐8 nanocubes as precursors. HMCNCs exhibit a cubic morphology with the particle sizes slightly larger than ZIF‐8 nanocubes. Due to the unique outward contraction process, uniform carbon nanocubes with a hollow cavity, an outer microporous shell, and an inner mesoporous wall are simultaneously formed with a large pore size (25 nm), high surface area (1085.7 m2 g−1), high porosity (3.77 cm3 g−1), and high nitrogen content (12.2%). When used as a cathode material for Li–SeS2 batteries, the HMCNCs deliver a stable capacity of 812.6 mA h g−1 at 0.2 A g−1 after 100 cycles and an outstanding rate capability (455.1 mA h g−1 at 5.0 A g−1). The findings may pave the way for the construction of distinctive MOF‐derived carbon materials for various applications.
A Highly Selective 3D Spiked Ultraflexible Neural (SUN) Interface for Decoding Peripheral Nerve Sensory Information
Authors: Wang Jiahui , Thow Xin Yuan , Wang Hao , Lee Sanghoon , Voges Kai , Thakor Nitish V. , Yen Shih‐Cheng , Lee Chengkuo
Published: December 2017

Artificial sensors on the skin are proposed as a way to capture information that can be used in intracortical microstimulation or peripheral intraneural stimulation to restore sensory feedback to persons with tetraplegia. However, the ability of these artificial sensors to replicate the density and complexity of the natural mechanoreceptors is limited. One relatively unexplored approach is to make use of the signals from surviving tactile and proprioceptive receptors in existing limbs by recording from their transmitting axons within the primary sensory nerves. Here, a novel spiked ultraflexible neural (SUN) interface that is implanted into the peripheral nervous system to capture sensory information from these mechanoreceptors in acute rat experiments is described. The novel 3D design, which integrates spiked structures for intrafascicular nerve recording with an ultraflexible substrate, enables a unique conformal interface to the target nerve. With the high‐quality recording (average signal‐to‐noise‐ratio of 1.4) provided by the electrode, tactile from proprioceptive stimuli can be differentiated in terms of the firing rate. In toe pinching experiments, high spatial resolution classification can be achieved with support vector machine classifier. Further work remains to be done to assess the chronic recording capability of the SUN interface.
Photoporation Using Carbon Nanotubes for Intracellular Delivery of Molecules and Its Relationship to Photoacoustic Pressure
Authors: Holguin Stefany Y. , Gray Michael D. , Joseph Princeton , Thadhani Naresh N. , Prausnitz Mark R.
Published: December 2017

Exposure of carbon‐black (CB) nanoparticles to near‐infrared nanosecond‐pulsed laser energy can cause efficient intracellular delivery of molecules by photoporation. Here, cellular bioeffects of multi‐walled carbon nanotubes (MWCNTs) and single‐walled carbon nanotubes (SWCNTs) are compared to those of CB nanoparticles. In DU145 prostate‐cancer cells, photoporation using CB nanoparticles transitions from (i) cells with molecular uptake to (ii) nonviable cells to (iii) fragmented cells with increasing laser fluence, as seen previously. In contrast, photoporation with MWCNTs causes uptake and, at higher fluence, fragmentation, but does not generate nonviable cells, and SWCNTs show little evidence of bioeffects, except at extreme laser conditions, which generate nonviable cells and fragmentation, but no significant uptake. These different behaviors cannot be explained by photoacoustic pressure output from the particles. All particle types emit a single, ≈100 ns, mostly positive‐pressure pulse that increases in amplitude with laser fluence. Different particle types emit different peak pressures, which are highest for SWCNTs, followed by CB nanoparticles and then MWCNTs, which does not correlate with cellular bioeffects between different particle types. This study concludes that cellular bioeffects depend strongly on the type of carbon nanoparticle used during photoporation and that photoacoustic pressure is unlikely to play a direct mechanistic role in the observed bioeffects.
Biodegradable Nanoparticles Enhanced Adhesiveness of Mussel‐Like Hydrogels at Tissue Interface
Authors: Pandey Nikhil , Hakamivala Amirhossein , Xu Cancan , Hariharan Prashant , Radionov Boris , Huang Zhong , Liao Jun , Tang Liping , Zimmern Philippe , Nguyen Kytai T. , Hong Yi
Published: December 2017

Popular bioadhesives, such as fibrin, cyanoacrylate, and albumin–glutaraldehyde based materials, have been applied for clinical applications in wound healing, drug delivery, and bone and soft tissue engineering; however, their performances are limited by weak adhesion strength and rapid degradation. In this study a mussel‐inspired, nanocomposite‐based, biodegradable tissue adhesive is developed by blending poly(lactic‐co‐glycolic acid) (PLGA) or N‐hydroxysuccinimide modified PLGA nanoparticles (PLGA‐NHS) with mussel‐inspired alginate–dopamine polymer (Alg‐Dopa). Adhesive strength measurement of the nanocomposites on porcine skin–muscle constructs reveals that the incorporation of nanoparticles in Alg‐Dopa significantly enhances the tissue adhesive strength compared to the mussel‐inspired adhesive alone. The nanocomposite formed by PLGA‐NHS nanoparticles shows higher lap shear strength of 33 ± 3 kPa, compared to that of Alg‐Dopa hydrogel alone (14 ± 2 kPa). In addition, these nanocomposites are degradable and cytocompatible in vitro, and elicit in vivo minimal inflammatory responses in a rat model, suggesting clinical potential of these nanocomposites as bioadhesives.
Wood‐Based Nanotechnologies toward Sustainability
Authors: Jiang Feng , Li Tian , Li Yiju , Zhang Ying , Gong Amy , Dai Jiaqi , Hitz Emily , Luo Wei , Hu Liangbing
Published: December 2017

With over 30% global land coverage, the forest is one of nature's most generous gifts to human beings, providing shelters and materials for all living beings. Apart from being sustainable, renewable, and biodegradable, wood and its derivative materials are also extremely fascinating from a materials aspect, with numerous advantages including porous and hierarchical structure, excellent mechanical performance, and versatile chemistry. Here, strategies for designing novel wood‐based materials via advanced nanotechnologies are summarized, including both the controllable bottom‐up assembly from the highly crystalline nanocellulose building block and the more efficient top‐down approaches directly from wood. Beyond material design, recent advances regarding the sustainable applications of these novel wood‐based materials are also presented, focusing on areas that are traditionally dominated by man‐made nonrenewable materials such as plastic, glass, and metals, as well as more advanced applications in the areas of energy storage, wastewater treatment and solar‐steam‐assisted desalination. With all recent progress pertaining to materials' design and sustainable applications presented, a vision for the future engineering of wood‐based materials to promote continuous and healthy progress toward true sustainability is outlined.
3D Printing of Living Responsive Materials and Devices
Authors: Liu Xinyue , Yuk Hyunwoo , Lin Shaoting , Parada German Alberto , Tang Tzu‐Chieh , Tham Eléonore , de la Fuente‐Nunez Cesar , Lu Timothy K. , Zhao Xuanhe
Published: December 2017

3D printing has been intensively explored to fabricate customized structures of responsive materials including hydrogels, liquid‐crystal elastomers, shape‐memory polymers, and aqueous droplets. Herein, a new method and material system capable of 3D‐printing hydrogel inks with programed bacterial cells as responsive components into large‐scale (3 cm), high‐resolution (30 μm) living materials, where the cells can communicate and process signals in a programmable manner, are reported. The design of 3D‐printed living materials is guided by quantitative models that account for the responses of programed cells in printed microstructures of hydrogels. Novel living devices are further demonstrated, enabled by 3D printing of programed cells, including logic gates, spatiotemporally responsive patterning, and wearable devices.
All‐Inorganic Perovskite Quantum Dots/p‐Si Heterojunction Light‐Emitting Diodes under DC and AC Driving Modes
Authors: Liu Jingjing , Sheng Xuexi , Wu Yangqing , Li Dongke , Bao Jianchun , Ji Yang , Lin Zewen , Xu Xiangxing , Yu Linwei , Xu Jun , Chen Kunji
Published: December 2017

Light‐emitting diodes based on perovskite quantum dots have attracted much attention since they can be applied in low‐cost display, biosensors, and other optoelectronic devices. Here, all‐inorganic light‐emitting diodes based on n‐type perovskite quantum dots/p‐Si heterojunction are fabricated. Both the green and the red light emission are achieved at room temperature. The output power density is 0.14 mW cm−2 for green light device and 0.25 mW cm−2 for the red one. The relatively low turn on voltage and high emission intensity in red light device can be attributed to the small hole injection barrier between CsPbI3 quantum dots and p‐Si. The emission drop off at high current density is observed under direct current (DC) driving mode, which is significantly improved by applying alternating current (AC) square pulses. The enhanced electroluminescence and the improved operation stability at high current density under AC driving mode can be attributed to the less thermal degradation and the reduced charge accumulation in the interface defect states due to the alternated biases. The results demonstrate the possibility of integrating the perovskite quantum dots with Si platform, which will be helpful to extend their actual applications.
Highly Stable and Efficient Lignin‐PEDOT/PSS Composites for Removal of Toxic Metals
Authors: Checkol Fekadu , Elfwing Anders , Greczynski Grzegorz , Mehretie Solomon , Inganäs Olle , Admassie Shimelis
Published: December 2017

A hybrid biopolymer/electronic polymer electrode is demonstrated here to extract metal ions, in this case lead, from water. The hybrid material consists of poly(3,4‐ethylenedioxythiophene)/polystyrene sulfonate (PEDOT/PSS) and the biopolymer lignin (LG) and is prepared by a simple one‐step galvanostatic polymerization from aqueous solution. The hybrid material is characterized by cyclic voltammetry, electrochemical quartz microbalance, X‐ray photoelectron spectroscopy, and scanning electron microscopy techniques. The electrochemical and spectroscopic results confirm that lead ions can be adsorbed on the composites films from a neutral solution of lead ions by applying a negative potential and subsequently desorbed from the hybrid films by applying positive potential. The adsorption capacity for lead ions on PEDOT/PSS is 245.5 mg g−1 and is almost doubled to 452.8 mg g−1 by incorporating LG into PEDOT/PSS.
Radiation‐Sensitive Dendrimer‐Based Drug Delivery System
Authors: Wu Szu‐Yuan , Chou Hsiao‐Ying , Yuh Chiou‐Hwa , Mekuria Shewaye Lakew , Kao Yu‐Chih , Tsai Hsieh‐Chih
Published: December 2017

Combination of chemotherapy and radiotherapy is used to enhance local drug delivery while reducing off‐target tissue effects. Anticancer drug doxorubicin (DOX) is loaded into l‐cysteine modified G4.5 dendrimer (GC/DOX) and released at different pH values in the presence and absence of γ‐radiation. Presence of γ‐radiation significantly improves DOX release from the GC/DOX under acidic pH conditions, suggesting that GC dendrimer is a radiation‐sensitive drug delivery system. GC/DOX is further evaluated by determining cytotoxicity in uterine cervical carcinoma HeLa cells. GC/DOX shows high affinity for cancer cells and effective drug release following an external stimulus (radiation exposure), whereas an in vivo zebrafish study confirms that l‐cysteine acts as a radiosensitizer. GC/DOX treatment combined with radiotherapy synergistically and successfully inhibits cancer cell growth.
Recent Progress on MOF‐Derived Heteroatom‐Doped Carbon‐Based Electrocatalysts for Oxygen Reduction Reaction
Authors: Ren Qian , Wang Hui , Lu Xue‐Feng , Tong Ye‐Xiang , Li Gao‐Ren
Published: December 2017

The oxygen reduction reaction (ORR) is the core reaction of numerous sustainable energy‐conversion technologies such as fuel cells and metal–air batteries. It is crucial to develop a cost‐effective, highly active, and durable electrocatalysts for ORR to overcome the sluggish kinetics of four electrons pathway. In recent years, the carbon‐based electrocatalysts derived from metal–organic frameworks (MOFs) have attracted tremendous attention and have been shown to exhibit superior catalytic activity and excellent intrinsic properties such as large surface area, large pore volume, uniform pore distribution, and tunable chemical structure. Here in this review, the development of MOF‐derived heteroatom‐doped carbon‐based electrocatalysts, including non‐metal (such as N, S, B, and P) and metal (such as Fe and Co) doped carbon materials, is summarized. It furthermore, it is demonstrated that the enhancement of ORR performance is associated with favorably well‐designed porous structure, large surface area, and high‐tensity active sites. Finally, the future perspectives of carbon‐based electrocatalysts for ORR are provided with an emphasis on the development of a clear mechanism of MOF‐derived non‐metal‐doped electrocatalysts and certain metal‐doped electrocatalysts.
Theoretical Study of Sliding‐Electrification‐Gated Tribotronic Transistors and Logic Device
Authors: Jiang Tao , Zhang Limin , Zhang Xu , Zhang Chi , Peng Wenbo , Xiao Tianxiao , Wang Zhong Lin
Published: December 2017

Triboelectric nanogenerators (TENG) were invented as a highly effective technology for harvesting ambient mechanical energy. By coupling the TENG and metal‐oxide‐semiconductor field‐effect transistor, a new field of tribotronics has been recently proposed using the electrostatic potential created by triboelectrification as a gate voltage to tune/control charge‐carrier transport in semiconductors. In this work, the performance of a sliding‐electrification‐gated tribotronic transistor (SGT) and a sliding‐electrification‐gated tribotronic logic device (SGL) are theoretically investigated. The drain–source current characteristics for both the N‐channel SGT and P‐channel SGT are calculated in enhancement and depletion modes, respectively, which are found to be controlled by triboelectric charge amount, sliding distance, and drain voltage. By scaling down the conduction channel length to 10 nm, the SGT can still work and exhibit similar current characteristic and charge‐transfer process, showing the great potential of tribotronics in large‐scale array integration. Furthermore, the operation principle of a designed SGL based on two N‐channel SGTs in enhancement mode is revealed. This work could provide in‐depth understanding of physical mechanisms for tribotronic devices and design guidance for potential applications of tribotronics.
Protons Enhance Conductivities in Lithium Halide Hydroxide/Lithium Oxyhalide Solid Electrolytes by Forming Rotating Hydroxy Groups
Authors: Song Ah‐Young , Xiao Yiran , Turcheniuk Kostiantyn , Upadhya Punith , Ramanujapuram Anirudh , Benson Jim , Magasinski Alexandre , Olguin Marco , Meda Lamartine , Borodin Oleg , Yushin Gleb
Published: December 2017

Li‐halide hydroxides (Li2OHX) and Li‐oxyhalides (Li3OX) have emerged as new classes of low‐cost, lightweight solid state electrolytes (SSE) showing promising Li‐ion conductivities. The similarity in the lattice parameters between them, careless synthesis, and insufficient rigor in characterization often lead to erroneous interpretations of their compositions. Finally, moisture remaining in the synthesis or cell assembling environment and variability in the equivalent circuit models additionally contribute to significant errors in their properties. Thus, there remains a controversy about the real values of Li‐ion conductivities in such SSEs. Here an ultra‐fast synthesis and comprehensive material characterization is utilized to report on the ionic conductivities of contaminant‐free Li2+xOH1−xCl (x=0‐0.7), and Li2OHBr not exceeding 10‐4 S cm‐1 at 110 °C. Using powerful combination of experimental and numerical approaches, it is demonstrated that the presence of H in these SSEs yields significantly higher Li+ ‐ionic conductivity. Born‐Oppenheimer molecular dynamics simulations show excellent agreement with experimental results and reveal an unexpected mechanism for faster Li+ transport. It involves rotation of a short OH‐group in SSEs, which opens lower‐energy pathways for the formation of Frenkel defects and highly‐correlated Li+ jumps. These findings will reduce the existing confusions and show new avenues for tuning SSE compositions for further improved Li‐ion conductivities.
Superior Oxygen Electrocatalysis on RuSexNanoparticles for Rechargeable Air Cathodes
Authors: Jang Ji‐Hoon , Lee Eunjik , Xiao Penghao , Park Kyusung , Kim In Young , Henkelman Graeme , Hwang Seong‐Ju , Kwon Young‐Uk , Goodenough John. B.
Published: December 2017

A one‐step, facile supercritical‐ethanol‐fluid synthesis of Se‐modified Ru nanoparticles nucleated on carbon defects is reported, and it is demonstrated that these nanoparticles provide, with >70% efficiency at 1 A g−1, a highly active and reversible oxygen‐reduction/oxygen‐evolution reaction on an air cathode in a nonaqueous electrolyte. The Se modification not only prevents Ru oxidation during charge/discharge cycling, but also improves the catalytic activity by promoting Li2O2versus Li2O deposited on the Ru particles during discharge. A computational calculation with density functional theory supports the role of a larger electron transfer to the oxygen of Li2O2adsorbed on a surface layer of RuSe2−δthan on a surface layer of RuO2, thereby shifting the more stable adsorbent from Li2O to Li2O2.
n‐Type SnSe2 Oriented‐Nanoplate‐Based Pellets for High Thermoelectric Performance
Authors: Luo Yubo , Zheng Yun , Luo Zhongzhen , Hao Shiqiang , Du Chengfeng , Liang Qinghua , Li Zhong , Khor Khiam Aik , Hippalgaonkar Kedar , Xu Jianwei , Yan Qingyu , Wolverton Chris , Kanatzidis Mercouri G.
Published: December 2017

It is reported that electron doped n‐type SnSe2 nanoplates show promising thermoelectric performance at medium temperatures. After simultaneous introduction of Se deficiency and Cl doping, the Fermi level of SnSe2 shifts toward the conduction band, resulting in two orders of magnitude increase in carrier concentration and a transition to degenerate transport behavior. In addition, all‐scale hierarchical phonon scattering centers, such as point defects, nanograin boundaries, stacking faults, and the layered nanostructures, cooperate to produce very low lattice thermal conductivity. As a result, an enhanced in‐plane thermoelectric figure of merit ZTmax of 0.63 is achieved for a 1.5 at% Cl doped SnSe1.95 pellet at 673 K, which is much higher than the corresponding in‐plane ZT of pure SnSe2 (0.08).
3D Amorphous Carbon with Controlled Porous and Disordered Structures as a High‐Rate Anode Material for Sodium‐Ion Batteries
Authors: Lu Peng , Sun Yi , Xiang Hongfa , Liang Xin , Yu Yan
Published: December 2017

Sodium‐ion batteries (SIBs) have a promising application prospect for energy storage systems due to the abundant resource. Amorphous carbon with high electronic conductivity and high surface area is likely to be the most promising anode material for SIBs. However, the rate capability of amorphous carbon in SIBs is still a big challenge because of the sluggish kinetics of Na+ ions. Herein, a three‐dimensional amorphous carbon (3DAC) with controlled porous and disordered structures is synthesized via a facile NaCl template‐assisted method. Combination of open porous structures of 3DAC, the increased disordered structures can not only facilitate the diffusion of Na+ ions but also enhance the reversible capacity of Na storage. When applied as anode materials for SIBs, 3DAC exhibits excellent rate capability (66 mA h g−1 at 9.6 A g−1) and high reversible capacity (280 mA h g−1 at a low current density of 0.03 A g−1). Moreover, the controlled porous structures by the NaCl template method provide an appropriate specific surface area, which contributes to a relatively high initial Coulombic efficiency of 75%. Additionally, the high‐rate 3DAC material is prepared via a green approach originating from low‐cost pitch and NaCl template, demonstrating an appealing development of carbon anode materials for SIBs.
Influence of mixing performance on polymerization of acrylamide in capillary microreactors
Authors: Song Yang , Shang Minjing , Li Guangxiao , Luo Zheng‐Hong , Su Yuanhai
Published: December 2017

Nonliving free radical polymerization of acrylamide was chosen as a model reaction to investigate the effect of mixing performance on the polymerization in capillary microreactors. The polymerization rate was enhanced by increasing the volumetric flow rate and the reaction temperature at a constant residence time. However, higher temperatures led to lower Mn and larger PDI. The reaction mixture viscosity increased significantly during the polymerization. Both diffusion and dispersion coefficients were calculated to evaluate the mixing performance in microreactors. The capillary microreactor with a larger inner diameter led to higher monomer conversions, lower Mn and larger PDI compared to the capillary microreactor with a smaller inner diameter, which could be explained through a heat balance analysis for the polymerization and the dispersion effect. Moreover, it was found that the addition of a pre‐mixing stage minimized the effect of insufficient mixing between the initiators and the monomers on the polymerization. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1828–1840, 2018
Combined effects of soot load and catalyst activity on the regeneration dynamics of catalytic diesel particulate filters
Authors: Di Sarli Valeria , Di Benedetto Almerinda
Published: December 2017

The combined effects of soot load and catalyst activity on the regeneration dynamics of a catalytic diesel particulate filter have been investigated through transient CFD‐based simulations of soot combustion in a single‐channel configuration. The soot load was changed by varying the amount of soot accumulated as cake layer, while keeping the amount of soot trapped inside the catalytic wall constant. Substantially uniform soot combustion that allows reasonably fast regeneration of the filter under controlled temperature conditions has been simulated only in the absence of cake and at relatively low catalyst activity. Conversely, in the presence of cake, numerical predictions have shown that, regardless of both soot load and catalyst activity, fast regeneration always occurs by propagation of sharp reaction fronts that result in high temperature rises. These findings highlight the importance of avoiding the cake formation, while properly optimizing the catalyst activity, to conduct a safe and effective regeneration of catalytic filters. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1714–1722, 2018
Conceptualising disability: A critical comparison between Indigenous people in Australia and New South Wales disability service agencies
Authors: Ravindran Subahari , Brentnall Jennie , Gilroy John
Published: December 2017

The lack of culturally appropriate services contributes to the low participation rate of Indigenous people in disability services. Understanding how disability is conceptualised is essential to developing culturally appropriate disability services. This study aimed to critically compare the conceptualisation of disability between Indigenous people and NSW government and non‐government disability service agencies. Indigenous and policy sources were obtained from purposive and snowball sampling. The Indigenous conceptualisation of disability was understood through representations by Indigenous spokespeople in journal and newspaper articles and audiovisual materials. The disability service agency conceptualisation of disability was represented through the annual reports and programme guidelines of the NSW government agency and seven non‐government disability agencies. The occupational justice framework guided critical analysis at the cultural interface. Four themes were identified: power and self‐determination, eligibility, otherness, and identity and labels. Data showed disability agencies promote self‐determination for Indigenous people and conceptualise disability as impairments affecting functioning, when assessing service access eligibility. Most Indigenous people do not self‐identify as disabled and are categorised as culturally different within policies. Indigenous people experience marginalisation due to their cultural identity. Indigenous people are required to conform to the conceptualisation of disability proffered by agencies to access services. To develop culturally appropriate services, agencies must collaborate with Indigenous communities.
Ischemic core thresholds change with time to reperfusion: A case control study
Authors: Bivard Andrew , Kleinig Tim , Miteff Ferdinand , Butcher Kenneth , Lin Longting , Levi Christopher , Parsons Mark
Published: December 2017

Introduction

We aimed to identify whether acute ischemic stroke patients with known complete reperfusion after thrombectomy had the same baseline computed tomography perfusion (CTP) ischemic core threshold to predict infarction as thrombolysis patients with complete reperfusion.

Methods

Patients who underwent thrombectomy were matched by age, clinical severity, occlusion location, and baseline perfusion lesion volume to patients who were treated with intravenous alteplase alone from the International Stroke Perfusion Imaging Registry. A pixel‐based analysis of coregistered pretreatment CTP and 24‐hour diffusion‐weighted imaging (DWI) was then undertaken to define the optimum CTP thresholds for the ischemic core.

Results

There were 132 eligible thrombectomy patients and 132 matched controls treated with alteplase alone. Baseline National Institutes of Health Stroke Scale (median, 15; interquartile range [IQR], 11–19), age (median, 65; IQR, 59–80), and time to intravenous treatment (median, 153 minutes; IQR, 82–315) were well matched (all p > 0.05). Despite similar baseline CTP ischemic core volumes using the previously validated measure (relative cerebral blood flow [rCBF], <30%), thrombectomy patients had a smaller median 24‐hour infarct core of 17.3ml (IQR, 11.3–32.8) versus 24.3ml (IQR, 16.7–42.2; p = 0.011) in alteplase‐treated controls. As a result, the optimal threshold to define the ischemic core in thrombectomy patients was rCBF <20% (area under the curve [AUC], 0.89; 95% CI, 0.84, 0.94), whereas in alteplase controls the optimal ischemic core threshold remained rCBF <30% (AUC, 0.83; 95% CI, 0.77, 0.85).

Interpretation

Thrombectomy salvaged tissue with lower CBF, likely attributed to earlier reperfusion. For patients who achieve rapid reperfusion, a stricter rCBF threshold to estimate the ischemic core should be considered. Ann Neurol 2017;82:995–1003
High‐Flux Zeolitic Imidazolate Framework Membranes for Propylene/Propane Separation by Postsynthetic Linker Exchange
Authors: Lee Moon Joo , Kwon Hyuk Taek , Jeong Hae‐Kwon
Published: December 2017

While zeolitic imidazolate framework, ZIF‐8, membranes show impressive propylene/propane separation, their throughput needs to be greatly improved for practical applications. A method is described that drastically reduces the effective thickness of ZIF‐8 membranes, thereby substantially improving their propylene permeance (that is, flux). The new strategy is based on a controlled single‐crystal to single‐crystal linker exchange of 2‐methylimidazole in ZIF‐8 membrane grains with 2‐imidazolecarboxaldehyde (ZIF‐90 linker), thereby enlarging the effective aperture size of ZIF‐8. The linker‐exchanged ZIF‐8 membranes showed a drastic increase in propylene permeance by about four times, with a negligible loss in propylene/propane separation factor when compared to as‐prepared membranes. The linker‐exchange effect depends on the membrane synthesis method.
Ultralong Phosphorescence from Organic Ionic Crystals under Ambient Conditions
Authors: Cheng Zhichao , Shi Huifang , Ma Huili , Bian Lifang , Wu Qi , Gu Long , Cai Suzhi , Wang Xuan , Xiong Wei‐wei , An Zhongfu , Huang Wei
Published: December 2017

A new type of materials, organic salts in the crystal state, have ultralong organic phosphorescence (UOP) under ambient conditions. The change of cations (NH4+, Na+, or K+) in these phosphors gives access to tunable UOP colors ranging from sky blue to yellow green, along with ultralong emission lifetimes of over 504 ms. Single‐crystal analysis reveals that unique ionic bonding can promote an ordered arrangement of organic salts in crystal state, which then can facilitate molecular aggregation for UOP generation. Additionally, reversible ultralong phosphorescence can be realized through the alternative employment of fuming gases (ammonia and hydrogen chloride), demonstrating its potential as a candidate for visual ammonic or hydrogen chloride gas sensing. The results provide an environmental responsible and practicable synthetic approach to expanding the scope of ultralong organic phosphorescent materials as well as their applications.
Kovalente organische Netzwerke und Käfigverbindungen: Design und Anwendungen von polymeren und diskreten organischen Gerüsten
Authors: Beuerle Florian , Gole Bappaditya
Published: December 2017

Poröse organische Materialien sind eine aufstrebende Klasse funktionaler Nanostrukturen mit beispiellosen Eigenschaften. Die dynamisch‐kovalente Organisation kleiner organischer Bausteine unter thermodynamischer Kontrolle wird dabei für die verblüffend einfache Bildung komplexer Architekturen in Eintopfreaktionen genutzt. In diesem Aufsatz werden die grundlegenden Designprinzipien analysiert, die zur Bildung von entweder kovalenten organischen Netzwerken als kristalline poröse Polymere oder kovalenten organischen Käfigverbindungen als formgetreue molekulare Objekte führen. Konventionelle Synthesevorschriften und Analysemethoden werden neben ausgefeilteren Strategien, wie postsynthetische Modifizierungen oder Selbstsortierung, diskutiert. Gegebenenfalls werden die entsprechenden Eigenschaften und Besonderheiten von polymeren Netzwerken und diskreten organischen Käfigen verglichen. Darüber hinaus wird das Potenzial dieser Materialien für Anwendungen, von der Gasspeicherung über die Katalyse bis hin zur organischen Elektronik, erörtert.
Formation and Isolation of a Four‐Electron‐Reduced Porphyrin Derivative by Reduction of a Stable 20π Isophlorin
Authors: Suzuki Wataru , Kotani Hiroaki , Ishizuka Tomoya , Shiota Yoshihito , Yoshizawa Kazunari , Kojima Takahiko
Published: December 2017

The two‐electron reduction of a diprotonated dodecaphenylporphyrin derivative by Na2S2O4 gave a corresponding isophlorin (Iph) selectively. Formation of Iph was confirmed by spectroscopic measurements and the isolation of tetramethylated Iph. Further reduction of Iph proceeded to form an unprecedented four‐electron‐reduced porphyrin (IphH2), which was fully characterized by spectroscopic and X‐ray crystallographic analysis. IphH2, with a unique conformation, could be oxidized to reproduce the starting porphyrin, resulting in a proton‐coupled four‐electron reversible redox system.
Triangles and Squares for a Unique Molecular Crystal Structure: Unsupported Two‐Coordinate Lithium Cations and CC Agostic Interactions in Cyclopropyllithium Derivatives
Authors: Dufrois Quentin , Daran Jean‐Claude , Vendier Laure , Dinoi Chiara , Etienne Michel
Published: December 2017

Understanding and controlling the aggregation state is germane to alkyllithium chemistry. Lewis base‐free alkyllithium compounds normally form tetrahedral tetramers or octahedral hexamers in the solid state with the lithium cations being three‐coordinate. We report that the unsupported cyclopropyl derivative 1‐(trimethylsilyl)cyclopropyllithium [{μ‐c‐C(SiMe3)C2H4}Li]4 (1), synthesized by the reduction of 1‐(phenylthio)‐1‐(trimethylsilyl)cyclopropane, crystallizes as a tetramer in the space group I‐4 with the two‐coordinate lithium atoms forming a square. CC agostic interactions complete the coordination sphere around each lithium. The aggregate is preserved in hydrocarbon solution. Furthermore, CC agostic interactions compete intra‐ and intermolecularly with Lewis base donation as in the unsaturated dimer of 1‐(phenylthio)cyclopropyllithium [Li(thf)2{μ‐c‐C(SPh)C2H4}2Li (thf)] (3) which is also fully characterized.
Diversity‐Oriented Synthesis of Furo[3,2‐c]coumarins and Benzofuranyl Chromenones through Chemoselective Acylation/Wittig Reaction
Authors: Yang Shu‐Mei , Wang Chein‐Yi , Lin Chun‐Kai , Karanam Praneeth , Reddy Ganapuram Madhusudhan , Tsai Yi‐Ling , Lin Wenwei
Published: December 2017

A highly efficient and chemoselective one‐pot protocol for the diversity‐oriented synthesis of two types of coumarin‐based formal cross‐coupling adducts, furo[3,2‐c]coumarins and 3‐benzofuranyl chromenones, is described. Key attributes of the methodology are an initial chemoselective acylation of functionalized phosphorus zwitterions and a subsequent chemoselective intramolecular Wittig reaction that preferentially resulted in one of the two coumarin derivatives in high yield, depending on relative reactivities and the addition sequence of the acylating agents.
Sinter‐Resistant Platinum Catalyst Supported by Metal–Organic Framework
Authors: Kim In Soo , Li Zhanyong , Zheng Jian , Platero‐Prats Ana E. , Mavrandonakis Andreas , Pellizzeri Steven , Ferrandon Magali , Vjunov Aleksei , Gallington Leighanne C. , Webber Thomas E. , Vermeulen Nicolaas A. , Penn R. Lee , Getman Rachel B. , Cramer Christopher J. , Chapman Karena W. , Camaioni Donald M. , Fulton John L. , Lercher Johannes A. , Farha Omar K. , Hupp Joseph T. , Martinson Alex B. F.
Published: December 2017

Single atoms and few‐atom clusters of platinum are uniformly installed on the zirconia nodes of a metal‐organic framework (MOF) NU‐1000 via targeted vapor‐phase synthesis. The catalytic Pt clusters, site‐isolated by organic linkers, are shown to exhibit high catalytic activity for ethylene hydrogenation while exhibiting resistance to sintering up to 200 °C. In situ IR spectroscopy reveals the presence of both single atoms and few‐atom clusters that depend upon synthesis conditions. Operando X‐ray absorption spectroscopy and X‐ray pair distribution analyses reveal unique changes in chemical bonding environment and cluster size stability while on stream. Density functional theory calculations elucidate a favorable reaction pathway for ethylene hydrogenation with the novel catalyst. These results provide evidence that atomic layer deposition (ALD) in MOFs is a versatile approach to the rational synthesis of size‐selected clusters, including noble metals, on a high surface area support.
Increasing Catalyst Efficiency in C−H Activation Catalysis
Authors: Gensch Tobias , James Michael J. , Dalton Toryn , Glorius Frank
Published: December 2017

C−H activation reactions with high catalyst turnover numbers are still very rare in the literature and 10 mol % is a common catalyst loading in this field. We offer a representative overview of efficient C−H activation catalysis to highlight this neglected aspect of catalysis development and inspire future effort towards more efficient C−H activation. Examples ranging from palladium catalysis, Cp*RhIII‐ and Cp*CoIII‐catalysis, the C−H borylation and silylation to methane C−H activation are presented. In these reactions, up to tens of thousands of catalyst turnovers have been observed.
Kinetics of solid acids catalysed nitration of toluene: Change in selectivity by triphase (liquid–liquid–solid) catalysis
Authors: Jeeru Lakshmana Rao , R. V. Saikumar Reddy , Pradhan Sayantan , Kundu Gautam , Pradhan Narayan C.
Published: December 2017

Nitrotoluenes are precursors to a variety of commercially important products such as dyes, pharmaceuticals, and plastics. The protonated form of Y, ZSM‐5, and mordenite zeolites as well as strongly acidic cation exchange resin (Amberlite IR‐120) were examined as triphase catalyst (liquid–liquid–solid) for the nitration of toluene to produce mainly mononitrotoluenes. Among the solid acid catalysts tested, zeolites were found to be more active than cation exchange resin with highest activity for H‐mordenite followed by HZSM‐5 and HY zeolites. The reaction was found to be free from external diffusional resistance. The effects of other parameters (temperature, catalyst loading, and nitric acid concentration) on the rate of toluene nitration over H‐mordenite catalyst were also investigated. The selectivity for p‐nitrotoluene increases with temperature but decreases with increase in nitric acid concentration. The acidity level of the catalyst determines the product distribution; the stronger the acidity, the lower the ortho/para ratio is in the product mixture. The triphasic nitration reaction is kinetically controlled with an activation energy of 24.24 kJ/mol. The catalyst could be reused for several cycles with negligible loss in activity.
A versatile radiochromic dosimeter for low‐medium gamma radiation and its application to food irradiation
Authors: Lopes Franceline Aparecida , Ferreira Giovana Ribeiro , Franco Marcella Rocha , Schimitberger Thiago , de Faria Luiz Oliveira , Bianchi Rodrigo Fernando
Published: December 2017

This article presents a novel radiochromic film for selective detection of low‐medium (0–10 kGy) gamma radiation (60Co) doses. This dosimeter is based on a printed fluorescent multilayer structure comprising a paper substrate having layers of copper phthalocyanine (DY220) (a green emitter material) on the bottom, and layers of poly[2‐methoxy‐5(2′‐ethylhexyloxy)‐p‐phenylenevinylene] (MEH‐PPV) (a green‐light absorber, red emitter, and radiation sensitive polymer) on the top. The effect of gamma radiation on the optical properties of DY220/MEH‐PPV was described: it was observed as a strong correlation between radiation dose and fluorescent, color coordinates for CIE (1931) chromatic diagram, and Pantone color reference of the dosimeter. The rate of these changes can be altered by manipulation of top–bottom layers to represent easily the radiation dose to be determined in a wide range. This versatile dosimeter has many uses in the field of food radiation for monitoring, quality assurance, and control of the gamma radiation process. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45729.
Low‐viscosity and soluble phthalonitrile resin with improved thermostability for organic wave‐transparent composites
Authors: Wu Zuoqiang , Li Nan , Han Jianhua , Wang Chenghao , Yuan Kuanyu , Zeng Qiang , Wang Jinyan , Jian Xigao
Published: December 2017

High processing viscosity and poor solubility limit the application of heterocyclic polymers for fabricating organic wave‐transparent composites for aerospace applications. In this paper, a novel resin, poly(phthalazinone ether bisphenol fluorene) encapped with phthalonitrile (PPEBF‐Ph), was synthesized and used as the matrix. Biphenol‐based phthalonitrile monomer BP‐Ph was also synthesized and blended with PPEBF‐Ph to further lower the processing viscosity. Solubility tests showed that the resin was soluble in dimethylformamide, N,N‐dimethyl acetamide, N‐methylpyrrolidone, dimethyl sulfoxide, chloroform, and other solvents. Differential scanning calorimetry and rheological studies revealed that the mixed resins exhibited low processing viscosity and a wide processing window below the gel temperature. Thermogravimetric analysis indicated that the cured resins were stable below 510–530 °C under nitrogen atmosphere after 6 h of curing (decreased by 40–60% compared with previous reports on phthalonitrile resin). In air, the char yields of the resins reached 20–30% when heated at 800 °C. The composites were reinforced by a quartz fiber cloth and exhibited a dielectric constant of 2.94–3.27 in an electromagnetic field with frequency ranging from 8 to 18 GHz. Retention of the bending modulus exceeded 70% at 400 °C according to dynamic mechanical analysis, indicating excellent mechanical stability was obtained. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45976.