bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Geographic Diversification on Risk Pooling to Mitigate Drought‐Related Financial Losses for Water Utilities
Authors: Baum Rachel , Characklis Gregory W. , Serre Marc L.
Published: March 2018

As the costs and regulatory barriers to new water supply development continue to rise, drought management strategies have begun to rely more heavily on temporary conservation measures. While these measures are effective, they often lead to intermittent and unpredictable reductions in revenues that are financially disruptive to water utilities, raising concerns over lower credit ratings and higher rates of borrowing for this capital intensive sector. Consequently, there is growing interest in financial risk management strategies that reduce utility vulnerabilities. This research explores the development of financial index insurance designed to compensate a utility for drought‐related losses. The focus is on analyzing candidate hydrologic indices that have the potential to be used by utilities across the US, increasing the potential for risk pooling, which would offer the possibility of both lower risk management costs and more widespread implementation. This work first analyzes drought‐related financial risks for 315 publicly operated water utilities across the country and examines the effectiveness of financial contracts based on several indices both in terms of their correlation with utility revenues and their spatial autocorrelation across locations. Hydrologic‐based index insurance contracts are then developed and tested over a 120 year period. Results indicate that risk pooling, even under conditions in which droughts are subject to some level of spatial autocorrelation, has the potential to significantly reduce the cost of managing financial risk.
Quantifying Surface Water, Porewater, and Groundwater Interactions Using Tracers: Tracer Fluxes, Water Fluxes, and End‐member Concentrations
Authors: Cook Peter G. , Rodellas Valentí , Stieglitz Thomas C.
Published: March 2018

Tracer approaches to estimate both porewater exchange (the cycling of water between surface water and sediments, with zero net water flux) and groundwater inflow (the net flow of terrestrially derived groundwater into surface water) are commonly based on solute mass balances. However, this requires appropriate characterization of tracer end‐member concentrations in exchanging or discharging water. Where either porewater exchange or groundwater inflow to surface water occur in isolation, then the water flux is easily estimated from the net tracer flux if the end‐member is appropriately chosen. However, in most natural systems porewater exchange and groundwater inflow will occur concurrently. Our analysis shows that if groundwater inflow (Qg) and porewater exchange (Qp) mix completely before discharging to surface water, then the combined water flux (Qg + Qp) can be approximated by dividing the combined tracer flux by the difference between the porewater and surface water concentrations, (cp – c). If Qg and Qp do not mix prior to discharge, then (Qg + Qp) can only be constrained by minimum and maximum values. The minimum value is obtained by dividing the net tracer flux by the groundwater concentration, and the maximum is obtained by dividing by (cp – c). Dividing by the groundwater concentration gives a maximum value for Qg. If porewater exchange and groundwater outflow occur concurrently, then dividing the net tracer flux by (cp – c) will provide a minimum value for Qp. Use of multiple tracers, and spatial and temporal replication should provide a more complete picture of exchange processes and the extent of subsurface mixing.
North Korea's 2017 Test and its Nontectonic Aftershock
Authors: Liu J. , Li L. , Zahradník J. , Sokos E. , Liu C. , Tian X.
Published: March 2018

Seismology illuminates physical processes occurring during underground explosions, not all yet fully understood. The thus‐far strongest North Korean test of 3 September 2017 was followed by a moderate seismic event (mL 4.1) after 8.5 min. Here we provide evidence that this aftershock was a nontectonic event which radiated seismic waves as a buried horizontal closing crack. This vigorous crack closure, occurring shortly after the blast, is studied in the North Korea test site for the first time. The event can be qualitatively explained as rapid destruction of an explosion‐generated cracked rock chimney due to cavity collapse, although other compaction processes cannot be ruled out.
Discovery of a Powerful, Transient, Explosive Thermal Event at Marduk Fluctus, Io, in Galileo NIMS Data
Authors: Davies A. G. , Davies R. L. , Veeder G. J. , de Kleer K. , de Pater I. , Matson D. L. , Johnson T. V. , Wilson L.
Published: March 2018

Analysis of Galileo Near‐Infrared Mapping Spectrometer observations of Marduk Fluctus, a volcano on the Jovian moon Io, reveals a style of volcanic activity not previously seen there—a powerful thermal event lasting only a few minutes in 1996. The thermal emission rapidly fades, suggesting extremely rapid cooling of small clasts. The duration and evolution of the explosive eruption are akin to what might be expected from a strombolian or vulcanian explosion. The presence of such events provides an additional volcanic process that can be imaged by future missions with the intent of determining lava composition from eruption temperature, an important constraint on the internal composition of Io. These data promise to be of particular use in understanding the mechanics of explosive volcanic processes on Io.
Predicting dating behavior from aggression and self‐perceived social status in adolescence
Authors: Lee Kirsty S. , Brittain Heather , Vaillancourt Tracy
Published: March 2018

We investigated the longitudinal associations between self‐reported aggression, self‐perceived social status, and dating in adolescence using an intrasexual competition theoretical framework. Participants consisted of 536 students in Grade 9 (age 15), recruited from a community sample, who were assessed on a yearly basis until they were in Grade 11 (age 17). Adolescents self‐reported their use of direct and indirect aggression, social status, and number of dating partners. A cross‐lagged panel model that controlled for within‐time covariance and across‐time stability while examining cross‐lagged pathways was used to analyze the data. The findings revealed that direct aggression did not predict dating behavior and was negatively associated with self‐perceived social status in Grade 10. Self‐perceived social status in Grade 9 was positively associated with greater use of indirect aggression in Grade 10. Regarding dating, in Grade 9, self‐perceived social status positively predicted more dating partners the following year, while in Grade 10, it was higher levels of indirect aggression that predicted greater dating activity the following year. Overall, there were no significant sex differences in the model. The study supports the utility of evolutionary psychological theory in explaining peer aggression, and suggests that although social status can increase dating opportunities, as adolescents mature, indirect aggression becomes the most successful and strategic means of competing intrasexually and gaining mating advantages.
COMP report: CPQR technical quality control guidelines for low‐dose‐rate permanent seed brachytherapy
Authors: Beaulieu Luc , Radford Dee‐Ann , Eduardo Villarreal‐Barajas J.
Published: March 2018

The Canadian Organization of Medical Physicists (COMP), in close partnership with the Canadian Partnership for Quality Radiotherapy (CPQR) has developed a series of Technical Quality Control (TQC) guidelines for radiation treatment equipment. These guidelines outline the performance objectives that equipment should meet in order to ensure an acceptable level of radiation treatment quality. The TQC guidelines have been rigorously reviewed and field tested in a variety of Canadian radiation treatment facilities. The development process enables rapid review and update to keep the guidelines current with changes in technology. This article contains detailed performance objectives and safety criteria for low‐dose‐rate (LDR) permanent seed brachytherapy.
Clinical acceptance testing and scanner comparison of ultrasound shear wave elastography
Authors: Long Zaiyang , Tradup Donald J. , Song Pengfei , Stekel Scott F. , Chen Shigao , Glazebrook Katrina N. , Hangiandreou Nicholas J.
Published: March 2018

Because of the rapidly growing use of ultrasound shear wave elastography (SWE) in clinical practices, there is a significant need for development of clinical physics performance assessment methods for this technology. This study aims to report two clinical medical physicists’ tasks: (a) acceptance testing (AT) of SWE function on ten commercial ultrasound systems for clinical liver application and (b) comparison of SWE measurements of targets across vendors for clinical musculoskeletal application. For AT, ten GE LOGIQ E9 XDclear 2.0 scanners with ten C1‐6‐D and ten 9L‐D transducers were studied using two commercial homogenous phantoms. Five measurements were acquired at two depths for each scanner/transducer pair by two operators. Additional tests were performed to access effects of different coupling media, phantom locations and operators. System deviations were less than 5% of group mean or three times standard deviation; therefore, all systems passed AT. A test protocol was provided based on results that no statistically significant difference was observed between using ultrasound gel and salt water for coupling, among different phantom locations, and that interoperator and intraoperator coefficient of variation was less than 3%. For SWE target measurements, two systems were compared — a Supersonic Aixplorer scanner with a SL10‐2 and a SL15‐4 transducer, and an abovementioned GE scanner with 9L‐D transducer. Two stepped cylinders with diameters of 4.05–10.40 mm were measured both longitudinally and transaxially. Target shear wave speed quantification was performed using an in‐house MATLAB program. Using the target shear wave speed deduced from phantom specs as a reference, SL15‐4 performed the best at the measured depth. However, it was challenging to reliably measure a 4.05 mm target for either system. The reported test methods and results could provide important information when dealing with SWE‐related tasks in the clinical environment.
Optimal model‐free control for a generic MIMO nonlinear system with application to autonomous mobile robots
Authors: Safaei Ali , Mahyuddin Muhammad Nasiruddin
Published: March 2018

In this paper, the design procedure for optimal model‐free control algorithm is presented for the tracking problem of completely unknown nonlinear dynamic systems operating under unknown disturbances. The procedure includes a new structure in the context of model‐free control and data‐driven control algorithms. In the new structure, the unknown nonlinear functions are segmented into 1 unknown linear‐in‐states part and another unknown nonlinear part. The adaptive laws proposed for estimating the unknown system dynamics are regressor‐free estimation methods in which there is no need for regressor parameters and, consequently, the persistent excitation condition is not required anymore. Moreover, the main controller gains are updated online, incorporating the adapted values of linear terms in the system dynamics. A comparative study is presented to show that the proposed optimal model‐free control outperforms the state‐of‐the‐art model‐free control algorithms. In addition, the simulation results for the application of the algorithm on autonomous mobile robots are provided.
Tunable 3D Nanoresonators for Gas‐Sensing Applications
Authors: Arnold Georg , Winkler Robert , Stermitz Martin , Orthacker Angelina , Noh Joo‐Hyon , Fowlkes Jason D. , Kothleitner Gerald , Huth Michael , Rack Philip D. , Plank Harald
Published: March 2018

The detection of gas species with high sensitivity is a significant task for fundamental sciences as well as for industrial applications. Similarly, the ongoing trend for device miniaturization brings new challenges for advanced fabrication including on‐demand functionality tuning. Following this motivation, here the additive, direct‐write fabrication of freestanding 3D nanoarchitectures is introduced, which can be brought into mechanical resonance via electric AC fields. Specifically, this study focuses on the 3D nanostructure synthesis, the subsequent determination of Young's modulus, and demonstrates a postgrowth procedure, which can precisely tune the material modulus. As‐fabricated resonators reveal a Young's modulus of 9–13 GPa, which can be increased by a factor greater than 5. Next, the electric readout of the resonance behavior is demonstrated via electric current measurement as an essential element for the resonance sensor applications. Finally, the implications of gas‐physisorption and gas‐chemisorption on the resonance frequencies are studied, representing a proof‐of‐principle for sensing applications by the here presented approach.
Controlled Growth of MoS2 Nanosheets on 2D N‐Doped Graphdiyne Nanolayers for Highly Associated Effects on Water Reduction
Authors: Yu Huidi , Xue Yurui , Hui Lan , Zhang Chao , Zhao Yingjie , Li Zhibo , Li Yuliang
Published: March 2018

The first utilization of nitrogen‐doped graphdiyne (NGDY) as an efficient catalytic promoter for hydrogen evolution reaction (HER) is reported. X‐ray powder diffraction and X‐ray photoelectron spectroscopy studies indicate the presence of strong interactions between NGDY and MoS2, which should effectively facilitate the charge transport behavior and improvement of the HER kinetics. The creative hybridization of MoS2 and NGDY endows such heterostructure with structural and compositional advantages for boosting the catalytic activity (low overpotential of 186 mV at 10 mA cm−2 and Tafel slope of 63 mV dec−1) and extraordinary stability (higher than all reported MoS2‐based materials and even better than that of commercial Pt and almost all benchmarked electrocatalysts). All of the results not only demonstrate that NGDY can be used as an effective catalytic promoter for hydrogen production, but also provide new strategy for fabricating efficient water‐splitting electrodes.
Combining 3D Printing with Electrospinning for Rapid Response and Enhanced Designability of Hydrogel Actuators
Authors: Chen Tingting , Bakhshi Hadi , Liu Li , Ji Jian , Agarwal Seema
Published: March 2018

Porous structures have emerged as a breakthrough of shape‐morphing hydrogels to achieve a rapid response. However, these porous actuators generally suffer from a lack of complexity and diversity in obtained 3D shapes. Herein, a simple yet versatile strategy is developed to generate shape‐morphing hydrogels with both fast deformation and enhanced designability in 3D shapes by combining two promising technologies: electrospinning and 3D printing. Elaborate patterns are printed on mesostructured stimuli‐responsive electrospun membranes, modulating in‐plane and interlayer internal stresses induced by swelling/shrinkage mismatch, and thus guiding morphing behaviors of electrospun membranes to adapt to changes of the environment. With this strategy, a series of fast deformed hydrogel actuators are constructed with various distinctive responsive behaviors, including reversible/irreversible formations of 3D structures, folding of 3D tubes, and formations of 3D structures with multi low‐energy states. It is worth noting that although poly(N‐isopropyl acrylamide) is chosen as the model system in the present research, our strategy is applicable to other stimuli‐responsive hydrogels, which enriches designs of rapid deformed hydrogel actuators.
3D Printing of Customized Li‐Ion Batteries with Thick Electrodes
Authors: Wei Teng‐Sing , Ahn Bok Yeop , Grotto Julia , Lewis Jennifer A.
Published: March 2018

The growing demand for rechargeable lithium‐ion batteries (LIBs) with higher capacity in customized geometries underscores the need for new battery materials, architectures, and assembly strategies. Here, the design, fabrication, and electrochemical performance of fully 3D printed LIBs composed of thick semisolid electrodes that exhibit high areal capacity are reported. Specifically, semisolid cathode and anode inks, as well as UV curable packaging and separator inks for direct writing of LIBs in arbitrary geometries are created. These fully 3D printed and packaged LIBs, which are encased between two glassy carbon current collectors, deliver an areal capacity of 4.45 mAh cm−2 at a current density of 0.14 mA cm−2, which is equivalent to 17.3 Ah L−1. The ability to produce high‐performance LIBs in customized form factors opens new avenues for integrating batteries directly within 3D printed objects.
Tailoring Porous Silicon for Biomedical Applications: From Drug Delivery to Cancer Immunotherapy
Authors: Li Wei , Liu Zehua , Fontana Flavia , Ding Yaping , Liu Dongfei , Hirvonen Jouni T. , Santos Hélder A.
Published: March 2018

In the past two decades, porous silicon (PSi) has attracted increasing attention for its potential biomedical applications. With its controllable geometry, tunable nanoporous structure, large pore volume/high specific surface area, and versatile surface chemistry, PSi shows significant advantages over conventional drug carriers. Here, an overview of recent progress in the use of PSi in drug delivery and cancer immunotherapy is presented. First, an overview of the fabrication of PSi with various geometric structures is provided, with particular focus on how the unique geometry of PSi facilitates its biomedical applications, especially for drug delivery. Second, surface chemistry and modification of PSi are discussed in relation to the strengthening of its performance in drug delivery and bioimaging. Emerging technologies for engineering PSi‐based composites are then summarized. Emerging PSi advances in the context of cancer immunotherapy are also highlighted. Overall, very promising research results encourage further exploration of PSi for biomedical applications, particularly in drug delivery and cancer immunotherapy, and future translation of PSi into clinical applications.
Anomalous‐Diffusion‐Assisted Brightness in White Cellulose Nanofibril Membranes
Authors: Toivonen Matti S. , Onelli Olimpia D. , Jacucci Gianni , Lovikka Ville , Rojas Orlando J. , Ikkala Olli , Vignolini Silvia
Published: March 2018

The understanding of the interaction between light and complex, random structures is the key for designing and tailoring the optical appearance and performance of many materials that surround us, ranging from everyday consumer products, such as those for personal care, paints, and paper, to light diffusers used in the LED‐lamps and solar cells. Here, it is demonstrated that the light transport in membranes of pure cellulose nanofibrils (CNFs) can be controlled to achieve bright whiteness in structures only a few micrometers thick. This is in contrast to other materials, such as paper, which require hundreds of micrometers to achieve a comparable appearance. The diffusion of light in the CNF membranes is shown to become anomalous by tuning the porosity and morphological features. Considering also their strong mechanical properties and biocompatibility, such white coatings are proposed as a new application for cellulose nanofibrils.
An Overview of Materials with Triply Periodic Minimal Surfaces and Related Geometry: From Biological Structures to Self‐Assembled Systems
Authors: Han Lu , Che Shunai
Published: March 2018

Triply periodic minimal surface structures and related geometries are widely identified in many natural systems, such as biological membranes and biophotonic structures in butterfly‐wing scales. Inspired by their marvelous and highly symmetrical structures and optimized physical properties, these structures have sparked immense interest for creating novel materials by extracting the design from nature. Significant progress has been made to understand these biological structures and fabricate artificial materials by top‐down and bottom‐up approaches for numerous applications in chemistry and materials science. Herein, research achievements, including theoretical and experimental discoveries, in both biological systems and the artificial synthesis of materials with triply periodic minimal surface structures and related materials are summarized. Recent developments in self‐assembled lyotropic liquid crystal phases, block copolymer systems, and their inorganic replicas are discussed in detail.
Air‐Stable and High‐Performance Solution‐Processed Organic Light‐Emitting Devices Based on Hydrophobic Polymeric Ionic Liquid Carrier‐Injection Layers
Authors: Sato Shugo , Ohisa Satoru , Hayashi Yukihiro , Sato Ryo , Yokoyama Daisuke , Kato Tetsuya , Suzuki Michinori , Chiba Takayuki , Pu Yong‐Jin , Kido Junji
Published: March 2018

A lot of research, mostly using electron‐injection layers (EILs) composed of alkali‐metal compounds has been reported with a view to increase the efficiency of solution‐processed organic light‐emitting devices (OLEDs). However, these materials have intractable properties, such as a strong affinity for moisture, which cause the degradation of OLEDs. Consequently, optimal EIL materials should exhibit high electron‐injection efficiency as well as be stable in air. In this study, polymer light‐emitting devices (PLEDs) based on the commonly used yellow‐fluorescence‐emitting polymer F8BT, which utilize poly(diallyldimethylammonium)‐based polymeric ionic liquids, are experimentally and analytically investigated. As a result, the optimized PLED employing an EIL comprising poly(diallyldimethylammonium) bis(trifluoromethanesulfonyl)imide (poly(DDA)TFSI), which is expected to display good moisture resistance because of water repellency of fluorocarbon groups, exhibits excellent storage stability in air and electroluminescence performance with a low turn‐on voltage of 2.01 V, maximum external quantum efficiency of 9.00%, current efficiency of 30.1 cd A−1, and power efficiency of 32.4 lm W−1. The devices with poly(DDA)TFSI show one of the highest efficiencies as compared to the reported standard PLEDs. Moreover, poly(DDA)TFSI is applied as a hole‐injection layer (HIL). The optimized PLED using poly(DDA)TFSI as the HIL exhibits performances comparable to those of a device that uses a conventional poly(3,4‐ethylenedioxy‐thiophene):poly(4‐styrenesulfonate) HIL.
Creating Stiff, Tough, and Functional Hydrogel Composites with Low‐Melting‐Point Alloys
Authors: Takahashi Riku , Sun Tao Lin , Saruwatari Yoshiyuki , Kurokawa Takayuki , King Daniel R. , Gong Jian Ping
Published: March 2018

Reinforcing hydrogels with a rigid scaffold is a promising method to greatly expand the mechanical and physical properties of hydrogels. One of the challenges of creating hydrogel composites is the significant stress that occurs due to swelling mismatch between the water‐swollen hydrogel matrix and the rigid skeleton in aqueous media. This stress can cause physical deformation (wrinkling, buckling, or fracture), preventing the fabrication of robust composites. Here, a simple yet versatile method is introduced to create “macroscale” hydrogel composites, by utilizing a rigid reinforcing phase that can relieve stress‐induced deformation. A low‐melting‐point alloy that can transform from a load‐bearing solid state to a free‐deformable liquid state at relatively low temperature is used as a reinforcing skeleton, which enables the release of any swelling mismatch, regardless of the matrix swelling degree in liquid media. This design can generally provide hydrogels with hybridized functions, including excellent mechanical properties, shape memory, and thermal healing, which are often difficult or impossible to achieve with single‐component hydrogel systems. Furthermore, this technique enables controlled electrochemical reactions and channel‐structure templating in hydrogel matrices. This work may play an important role in the future design of soft robots, wearable electronics, and biocompatible functional materials.
Molecular‐Level Hybridization of Nafion with Quantum Dots for Highly Enhanced Proton Conduction
Authors: Wu Wenjia , Li Yifan , Liu Jindun , Wang Jingtao , He Yakun , Davey Kenneth , Qiao Shi‐Zhang
Published: March 2018

Nanophase‐separated membranes hold promise for fast molecule or ion transfer. However, development and practical application are significantly hindered by both the difficulty of chemical modification and nanophase instability. This can be addressed by organic–inorganic hybridization of functional fillers with a precise distribution in specific nanophase. Here, a molecular‐level hybridization for nanophase‐separated Nafion using 2–5 nm quantum dots (QDs) as a new smart filler is demonstrated. Two kinds of QDs are prepared and used: hydrophilic polymer‐like QDs (PQDs) and hydrophobic graphene oxide QDs (GQDs). Because of selective interactions, QDs offer advantages of matched structural size and automatic recognition with the nanophase. A distinctive synthesis of subordinate‐assembly, in which QDs are driven by the self‐assembly of Nafion affinity chains, is reported. This results in a precise distribution of QDs in the ionic, or backbone, nanophases of Nafion. The resulting PQDs in the ionic nanophase significantly increase membrane proton conduction and device output‐power without loss of mechanical stability. This is difficult to realize with conventional fillers. The GQDs in the backbone nanophase reduce the crystallinity and significantly augment membrane water uptake and swelling capacities.
Amplified Detection of a Unique Genomic Viral Marker Using Fluorescently Labeled Liposomes
Authors: AbouShaheen Samir , Fakih Hassan H. , Kobeissi Jana M. , Karam Pierre
Published: March 2018

Sensitive and enzyme‐free detection of specific oligonucleotide sequences is a pressing need in the field of precision and personalized medicine. In this work the detection of a unique genetic marker for hepatitis B virus with a low detection limit of 5 × 10−12m and a fast assay time is reported. In the assay presented here, fluorescently labeled liposomes are captured by gold‐decorated polystyrene beads using the target sequence as the building block. This is achieved by modifying the microbeads and the liposomes each with half of the complementary sequence. After a short incubation time with the target of interest, the fluorescent signal of the bridged bead–liposome assembly is detected via flow cytometry. Each liposome is labeled with ≈48 lipid soluble dyes resulting in an amplified fluorescent signal for every sensing event. The detection of the viral marker is even possible in an artificial serum‐spiked sample.
Acorn Barnacles Secrete Phase‐Separating Fluid to Clear Surfaces Ahead of Cement Deposition
Authors: Fears Kenan P. , Orihuela Beatriz , Rittschof Daniel , Wahl Kathryn J.
Published: March 2018

Marine macrofoulers (e.g., barnacles, tubeworms, mussels) create underwater adhesives capable of attaching themselves to almost any material. The difficulty in removing these organisms frustrates maritime and oceanographic communities, and fascinates biomedical and industrial communities seeking synthetic adhesives that cure and hold steadfast in aqueous environments. Protein analysis can reveal the chemical composition of natural adhesives; however, developing synthetic analogs that mimic their performance remains a challenge due to an incomplete understanding of adhesion processes. Here, it is shown that acorn barnacles (Amphibalanus (=Balanus) amphitrite) secrete a phase‐separating fluid ahead of growth and cement deposition. This mixture consists of a phenolic laden gelatinous phase that presents a phase rich in lipids and reactive oxygen species at the seawater interface. Nearby biofilms rapidly oxidize and lift off the surface as the secretion advances. While phenolic chemistries are ubiquitous to arthropod adhesives and cuticles, the findings demonstrate that A. amphitrite uses these chemistries in a complex surface‐cleaning fluid, at a substantially higher relative abundance than in its adhesive. The discovery of this critical step in underwater adhesion represents a missing link between natural and synthetic adhesives, and provides new directions for the development of environmentally friendly biofouling solutions.
From Charge Storage Mechanism to Performance: A Roadmap toward High Specific Energy Sodium‐Ion Batteries through Carbon Anode Optimization
Authors: Saurel Damien , Orayech Brahim , Xiao Biwei , Carriazo Daniel , Li Xiaolin , Rojo Teófilo
Published: March 2018

While sodium‐ion batteries (SIBs) represent a low‐cost substitute for Li‐ion batteries (LIBs), there are still several key issues that need to be addressed before SIBs become market‐ready. Among these, one of the most challenging is the negligible sodium uptake into graphite, which is the keystone of the present LIB technology. Although hard carbon has long been established as one of the best substitutes, its performance remains below that of graphite in LIBs and its sodium storage mechanism is still under debate. Many other carbons have been recently studied, some of which have presented capacities far beyond that of graphite. However, these also tend to exhibit larger voltage and high first cycle loss, leading to limited benefits in terms of full cell specific energy. Overcoming this concerning tradeoff necessitates a deep understanding of the charge storage mechanisms and the correlation between structure, microstructure, and performance. This review aims to address this by drawing a roadmap of the emerging routes to optimization of carbon materials for SIB anodes on the basis of a critical survey of the reported electrochemical performances and charge storage mechanisms.
High‐Performance and Low‐Temperature Lithium–Sulfur Batteries: Synergism of Thermodynamic and Kinetic Regulation
Authors: Fan Chao‐Ying , Zheng Yan‐Ping , Zhang Xiao‐Hua , Shi Yan‐Hong , Liu Si‐Yu , Wang Han‐Chi , Wu Xing‐Long , Sun Hai‐Zhu , Zhang Jing‐Ping
Published: March 2018

The intrinsic polysulfides shuttle, resulting from not only concentration‐gradient diffusion but also slow conversion kinetics of polysulfides, bears the primary responsibility for the poor capacity and cycle stability of lithium–sulfur batteries (LSBs). Here, it is first presented that enriched edge sites derived from vertical standing and ultrathin 2D layered metal selenides (2DLMS) can simultaneously achieve the thermodynamic and kinetic regulation for polysulfides diffusion, which is systematically elucidated through theoretical calculation, electrochemical characterization, and spectroscopic/microscopic analysis. When employed to fabricate compact coating layer of separator, an ultrahigh capacity of 1338.7 mA h g−1 is delivered after 100 cycles at 0.2 C, which is the best among the reports. Over 1000 cycles, the cell still maintains the capacity of 546.8 mA h g−1 at 0.5 C. Moreover, the cell exhibits outstanding capacities of 1106.2 and 865.7 mA h g−1 after 100 cycles at stern temperature of 0 and −25 °C. The superior low‐temperature performance is appealing for extended practical application of LSBs. Especially, in view of the economy, the 2DLMS is recycled as an anode of lithium‐ion and sodium‐ion batteries after finishing the test of LSBs. The low‐cost and scalable 2DLMS with enriched egde sites open a new avenue for the perfect regulation of the sulfur electrode.
Scale‐dependent nonequilibrium features in a bubbling fluidized bed
Authors: Wang Haifeng , Chen Yanpei , Wang Wei
Published: March 2018

We investigate experimentally the nonequilibrium features in a pseudo 2‐D bubbling fluidized bed. Velocities of individual particles are measured by using a particle tracking velocimetry (PTV) method, and void fractions are obtained with the Voronoi tessellation. A bimodal shape of probability density function (PDF) for particle vertical velocity is found in not only time‐averaged but also time‐varying statistics, which is caused by the transition between the dense and dilute phases and breaks the local‐equilibrium assumption in continuum modeling of fluidized beds. The results of time‐varying radial distribution function and voidage distribution also confirm this finding. Moreover, the analysis of voidage, particle velocity, granular temperature and turbulent kinetic energy of particles shows that there is no scale‐independent plateau over the interface, and it seems hard to find a scale‐independent plateau to separate the micro‐ and meso‐scales of fluidized beds, which require sub‐grid meso‐scale modeling for continuum or coarse‐graining methods of gas‐fluidized systems. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2364–2378, 2018
Life Goals Over Time Among Homeless Adults in Permanent Supportive Housing
Authors: Wenzel S.L. , Rhoades H. , Moore H. , Lahey J. , Henwood B. , La Motte‐Kerr W. , Bird M.
Published: March 2018

Permanent supportive housing (PSH) is a widely‐accepted solution to the challenge of chronic homelessness. While housing support and retention, physical health, and healthcare continue to be important for formerly homeless persons in PSH, “higher‐order” and humanistic needs such as thriving have received less attention and as a result are less well understood in this population. One important indicator of thriving is the ability to establish and articulate life goals. This study utilizes longitudinal data from 421 formerly homeless adults prior to their move into PSH, and at 3‐, 6‐ and 12‐months after move‐in (369 respondents completed all four interviews), to examine what life goals are articulated by this population and how those goals change over time. Prior to housing, most respondents articulated housing attainment as their primary life goal, whereas at follow‐up interviews health goals, housing relocation, and financial goals became more prevalent. Aspirational goals (e.g., independence, self‐improvement, artistic pursuits) were also common, but demonstrated a decrease over time in housing. Relationship goals remained common and consistent over time. Findings indicate that housing is a necessary, but perhaps not sufficient, step for improving thriving among formerly homeless adults. Implications for practice and future research are discussed.
Validation of endotoxin‐core antibodies in dried blood spots as a measure of environmental enteropathy and intestinal permeability
Authors: Hoke Morgan K. , McCabe Kimberly A. , Miller Aaron A. , McDade Thomas W.
Published: March 2018

Objective

To validate a method for measuring endotoxin‐core antibodies (EndoCAb) from dried blood spots (DBS)—drops of capillary whole blood collected and dried on filter paper—as an indicator of environmental enteropathy (EE) in infancy and early childhood.

Methods

A commercially available enzyme immunoassay kit was adapted for use with DBS, with optimized steps for sample elution. Technical validation included analysis of linearity/recovery, precision and reliability, lower limit of detection, and correspondence between matched plasma and DBS samples. Validation in a field‐based setting was implemented with samples from Peruvian infants (n = 82; age = 2–33 months) collected at two time points six months apart.

Results

A high correspondence between plasma and DBS levels of EndoCAb was observed (R2 = 0.93, P < .001). The lower limit of detection was found to be 0.01 GMU/mL. Interassay coefficient of variation (CV) was 10.9% and 8.06% for low and high controls, respectively. Mean intra‐assay CVs were 3.22% and 1.83%, respectively. In a sample of Peruvian infants, EndoCAb levels increased with age as expected (P < .001). Age explained nearly 34.6% of the variance in EndoCAb across the sample.

Conclusion

These findings demonstrate the validity and feasibility of measuring EndoCAb in remote field settings using minimally invasive DBS sampling.
An overview of health and safety in the Colorado cannabis industry
Authors: Walters Kevin M. , Fisher Gwenith G. , Tenney Liliana
Published: March 2018

Background

Understanding worker health and safety in the rapidly growing legal U.S. cannabis industry is important. Although little published research exists, workers may be exposed to biological, chemical, and physical hazards. This study investigated the Colorado cannabis industry workforce and both physical and psychosocial hazards to worker health and safety.

Methods

Two hundred and fourteen Colorado cannabis workers completed an online survey after in‐person and online recruitment. Participants answered questions about their occupation, job tasks, general well‐being, occupational health and safety, cannabis use, and tobacco use.

Results

Colorado cannabis workers were generally job secure and valued safety. However, they regularly consumed cannabis, expressed low concerns about workplace hazards, reported some occupational injuries and exposures, and reported inconsistent training practices.

Conclusions

Working in the cannabis industry is associated with positive outcomes for workers and their organizations, but there is an imminent need to establish formal health and safety training to implement best practices.
Von funktionellen Flüssigkristallen zur nächsten Generation von Materialien
Authors: Kato Takashi , Uchida Junya , Ichikawa Takahiro , Sakamoto Takeshi
Published: March 2018

Seit der Entdeckung des flüssigkristallinen Zustandes im Jahr 1888 wurden Flüssigkristalle unter Einsatz verschiedener Technologien in unterschiedlichen Disziplinen eingehend erforscht. In letzter Zeit wurden dank der Fortschritte bei Synthese‐ und Charakterisierungsmethoden ein neuartiges Moleküldesign und neue selbstorganisierte Strukturen entwickelt. Für diese Flüssigkristalle, deren neuartige Funktionen und Eigenschaften sich von ihren Nanostrukturen und ihrer Ausrichtung ableiten, wurde eine Vielzahl möglicher Anwendungen vorgeschlagen, etwa im Energietransport, in Trennverfahren für die Umwelttechnik, als Sensoren, Aktuatoren oder Template sowie auf der Grundlage von Farbänderungen oder elektrooptischen Effekten. Dieser Aufsatz präsentiert die neuesten Fortschritte bei Flüssigkristallen, die zu einer neuen Generation von Materialien führen könnten.
Synthesis of Crystalline Porous Organic Salts with High Proton Conductivity
Authors: Xing Guolong , Yan Tingting , Das Saikat , Ben Teng , Qiu Shilun
Published: March 2018

Self‐assembled crystalline porous organic salts (CPOSs) formed by an acid–base combination and with one‐dimensional polar channels containing water molecules have been synthesized. The water content in the channels of the porous salts plays an important role in the proton conduction performance of the materials. The porous salts described in this study feature high proton conductivity at ambient conditions and can reach as high as 2.2×10−2 S cm−1 at 333 K and under high humid conditions. This is among the best conductivity values reported to date for porous materials, for example, metal–organic frameworks and hydrogen‐bonded organic frameworks. These materials exhibiting permanent porosity represent a group of porous materials and may find interesting applications in proton‐exchange membrane fuel cells.
Engineering Fast Ion Conduction and Selective Cation Channels for a High‐Rate and High‐Voltage Hybrid Aqueous Battery
Authors: Liu Chunyi , Wang Xusheng , Deng Wenjun , Li Chang , Chen Jitao , Xue Mianqi , Li Rui , Pan Feng
Published: March 2018

The rechargeable aqueous metal‐ion battery (RAMB) has attracted considerable attention due to its safety, low costs, and environmental friendliness. Yet the poor‐performance electrode materials lead to a low feasibility of practical application. A hybrid aqueous battery (HAB) built from electrode materials with selective cation channels could increase the electrode applicability and thus enlarge the application of RAMB. Herein, we construct a high‐voltage K–Na HAB based on K2FeFe(CN)6 cathode and carbon‐coated NaTi2(PO4)3 (NTP/C) anode. Due to the unique cation selectivity of both materials and ultrafast ion conduction of NTP/C, the hybrid battery delivers a high capacity of 160 mAh g−1 at a 0.5 C rate. Considerable capacity retention of 94.3 % is also obtained after 1000 cycles at even 60 C rate. Meanwhile, high energy density of 69.6 Wh kg−1 based on the total mass of active electrode materials is obtained, which is comparable and even superior to that of the lead acid, Ni/Cd, and Ni/MH batteries.
Mild Friedel–Crafts Reactions inside a Hexameric Resorcinarene Capsule: C−Cl Bond Activation through Hydrogen Bonding to Bridging Water Molecules
Authors: La Manna Pellegrino , Talotta Carmen , Floresta Giuseppe , De Rosa Margherita , Soriente Annunziata , Rescifina Antonio , Gaeta Carmine , Neri Placido
Published: March 2018

A novel catalytic feature of a hexameric resorcinarene capsule is highlighted. The self‐assembled cage was exploited to promote the Friedel–Crafts benzylation of several arenes and heteroarenes with benzyl chloride under mild conditions. Calculations showed that there are catalytically relevant hydrogen‐bonding interactions between the bridging water molecules of the capsule and benzyl chloride, which is fundamental for the activation of the C−Cl bond. The capsule controls the reaction outcome. Inside the inner cavity of the capsule, N‐methylpyrrole is preferentially benzylated in the unusual β‐position while mesitylene reacts faster than 1,3‐dimethoxybenzene despite the greater π‐nucleophilicity of the latter compound.
Nicht‐kanonische RNA‐Nukleoside als molekulare Fossilien einer frühen Erde – Generierung durch präbiotische Methylierungen und Carbamoylierungen
Authors: Schneider Christina , Becker Sidney , Okamura Hidenori , Crisp Antony , Amatov Tynchtyk , Stadlmeier Michael , Carell Thomas
Published: March 2018

Die RNA‐Welt‐Hypothese besagt, dass das Leben auf der Erde mit kleinen RNA‐Molekülen begann, die in der Lage waren, sich selbst zu replizieren. Grundlegend für diese Hypothese ist der präbiotische Zugang zu RNA‐Polymeren. Heutige RNA besteht nicht nur aus den vier kanonischen Nukleosiden, sondern darüber hinaus aus vielen chemisch modifizierten RNA‐Bausteinen. Ob diese nicht‐kanonischen Nukleoside parallel zu den kanonischen Nukleosiden (chemischer Ursprung) oder später gebildet wurden (biologischer Ursprung), ist noch immer ungeklärt. Hier wird gezeigt, dass Isocyanate in Kombination mit Natriumnitrit methylierende und carbamoylierende Bedingungen schaffen, die kompatibel mit den Voraussetzungen auf der frühen Erde sind. Diese Reaktionen führen zur Bildung methylierter und Aminosäure‐modifizierter Nukleoside, die heute in der Biologie zu finden sind. Die Daten liefern ein plausibles Szenario für den chemischen Ursprung bestimmter nicht‐kanonischer Nukleoside, was darauf hindeutet, dass sie Fossilien der frühen Erde sein könnten.
Conjugated Dienyne‐Imides as Robust Precursors of 1‐Azatrienes for 6π Electrocyclizations to Furo[2,3‐b]dihydropyridine Cores
Authors: Wan Yanjun , Zheng Xuchun , Ma Cheng
Published: March 2018

A novel strategy to generate functionalized 1‐azatriene intermediates for 6π electrocyclizations was developed by using readily accessible dienyne‐imides and various terminal olefins under PdII catalysis. Taking advantage of the sequential cooperation between preloaded and incorporated functional handles at 1,3‐dien‐5‐yne skeletons, this method not only enables the selective generation of putative 1‐azatrienes but significantly accelerates their thermal 6π‐electrocyclic ring‐closure processes to a series of highly substituted furo[2,3‐b]dihydropyridine derivatives in good yields.
Strain‐Promoted Cycloaddition of Cyclopropenes with o‐Quinones: A Rapid Click Reaction
Authors: Gahtory Digvijay , Sen Rickdeb , Kuzmyn Andriy R. , Escorihuela Jorge , Zuilhof Han
Published: March 2018

Novel click reactions are of continued interest in fields as diverse as bio‐conjugation, polymer science and surface chemistry. Qualification as a proper “click” reaction requires stringent criteria, including fast kinetics and high conversion, to be met. Herein, we report a novel strain‐promoted cycloaddition between cyclopropenes and o‐quinones in solution and on a surface. We demonstrate the “click character” of the reaction in solution and on surfaces for both monolayer and polymer brush functionalization.
Enantioselective Denitrogenative Annulation of 1H‐Tetrazoles with Styrenes Catalyzed by Rhodium
Authors: Nakamuro Takayuki , Hagiwara Kohei , Miura Tomoya , Murakami Masahiro
Published: March 2018

Sulfonylation of 1H‐tetrazoles with triflic anhydride in the presence of chiral rhodium(II) carboxylate dimers causes denitrogenation to generate α‐azo rhodium(II) carbenoid species as new types of donor/acceptor carbenoids, which then readily react with styrenes to afford 3,5‐diaryl‐2‐pyrazolines with a high degree of enantioselectivity.
Bottleable Neutral Analogues of [B2H5]− as Versatile and Strongly Binding η2 Donor Ligands
Authors: Wang Sunewang R. , Prieschl Dominic , Mattock James D. , Arrowsmith Merle , Pranckevicius Conor , Stennett Tom E. , Dewhurst Rian D. , Vargas Alfredo , Braunschweig Holger
Published: March 2018

Herein we report the discovery that two bottleable, neutral, base‐stabilized diborane(5) compounds are able to bind strongly to a number of copper(I) complexes exclusively through their B−B bond. The resulting complexes represent the first known complexes containing unsupported, neutral σB−B diborane ligands. Single‐crystal X‐ray analyses of these complexes show that the X−Cu moiety (X=Cl, OTf, C6F5) lies opposite the bridging hydrogen atom of the diborane and is near perpendicular to the B−B bond, interacting almost equally with both boron atoms and causing a B−B bond elongation. DFT studies show that σ donation from and π backdonation to the pseudo‐π‐like B−B bond account for their formation. Astoundingly, these copper σB−B complexes are inert to ligand exchange with pyridine under either heating or photoirradiation.
Noncanonical RNA Nucleosides as Molecular Fossils of an Early Earth—Generation by Prebiotic Methylations and Carbamoylations
Authors: Schneider Christina , Becker Sidney , Okamura Hidenori , Crisp Antony , Amatov Tynchtyk , Stadlmeier Michael , Carell Thomas
Published: March 2018

The RNA‐world hypothesis assumes that life on Earth started with small RNA molecules that catalyzed their own formation. Vital to this hypothesis is the need for prebiotic routes towards RNA. Contemporary RNA, however, is not only constructed from the four canonical nucleobases (A, C, G, and U), it also contains many chemically modified (noncanonical) bases. A still open question is whether these noncanonical bases were formed in parallel to the canonical bases (chemical origin) or later, when life demanded higher functional diversity (biological origin). Here we show that isocyanates in combination with sodium nitrite establish methylating and carbamoylating reactivity compatible with early Earth conditions. These reactions lead to the formation of methylated and amino acid modified nucleosides that are still extant. Our data provide a plausible scenario for the chemical origin of certain noncanonical bases, which suggests that they are fossils of an early Earth.
The effect of citric acid on the catalytic activity of nano‐sized MoS2 toward sulfur‐resistant CO methanation
Authors: Li Zhenhua , Yin Zijia , Wang Weihan , Tian Ye , Wang Baowei , Ma Xinbin
Published: March 2018

In this work, a facile hydrothermal route was used to prepare nano‐sized MoS2 catalyst. The effect of citric acid during the MoS2 preparation process on the catalytic activity of sulfur‐resistant CO methanation was investigated. It was found that citric acid played an adverse role on the catalytic activity of MoS2 toward sulfur‐resistant CO methanation. However, CO methanation performance turned out to be better when NH2OH⋅HCl as a reductant was removed during the catalyst preparation process. The X‐ray diffraction (XRD) and infrared spectroscopy (IR) were performed to discuss the possible mechanism for the effect of citric acid towards CO methanation performance.