bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

SummaryIn 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

AbstractThe 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

AbstractThe 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

AbstractPorous 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

AbstractThe 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

AbstractIn 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

AbstractThe 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

AbstractTriply 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

AbstractA 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

AbstractReinforcing 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

AbstractNanophase‐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

AbstractSensitive 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

AbstractMarine 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

AbstractWhile 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

AbstractThe 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.
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

AbstractPermanent 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.