bluuebunny/crossref_metadata_2025_split huggingface dataset:
Poly(acrylic acid) hydrogel microparticles fabricated with silver nanoparticles: synthesis, characterization, and catalytic applications
Authors: Ajmal Muhammad , Anwar Saad , Naeem Hina , Zia Muhammad Abid , Siddiq Muhammad 
Published: September 2020

AbstractThis work narrates the synthesis of poly (acrylic acid) hydrogel microparticles (PAAHMPs), fabrication of silver nanoparticles (AgNPs) inside the structure of the prepared PAAHMPs and catalytic applications of PAAHMPs fabricated with AgNPs (PAAHMPs/AgNPs). The PAAHMPs were prepared by inverse suspension polymerization technique while fabrication of AgNPs was carried out by chemical reduction method using sodium borohydride (NaBH4) as reducing agent. The identification of functional groups in bare PAAHMPs and in the PAAHMPs/AgNPs composite system was carried out by the Fourier transform infrared spectroscopy. The size and morphology of the prepared hydrogel and its composite was studied by scanning electron microscopy and transmission electron microscopy. X‐ray diffraction and thermal gravimetric analyzer was also used to characterize the bare PAAHMPs and PAAHMPs/AgNPs composite. The prepared PAAHMPs/AgNPs composite was used as catalyst for the reduction of nitro aromatic pollutants and an industrial dye, that is, 4‐Nitrophenol (4‐NP), 2‐Nitrophenol (2‐NP) and methyl orange. No loss in catalytic activity was noted in seven consecutive cycles of recycling process while only 37.5% loss in catalytic activity was observed upon storing the catalyst for 90 days.
Spatial and stratigraphic variation of near‐surface ground ice in discontinuous permafrost of the taiga shield
Authors: Paul Jason R. , Kokelj Steven V. , Baltzer Jennifer L. 
Published: September 2020

AbstractThe acceleration of permafrost thaw due to warming, wetting, and disturbance is altering circumpolar landscapes. The effect of thaw is largely determined by ground ice content in near‐surface permafrost, making the characterization and prediction of ground ice content critical. Here we evaluate the spatial and stratigraphic variation of near‐surface ground ice characteristics in the dominant forest types in the North Slave region near Yellowknife, Northwest Territories, Canada. Physical variation in the permafrost was assessed through cryostructure, soil properties, and volumetric ice content, and relationships between these parameters were determined. Near‐surface ground ice characteristics were contrasted between forest types. In black spruce forests the top of the permafrost was ice‐rich and characterized by lenticular and ataxitic cryostructures, indicating the presence of an intermediate layer. Most white spruce/birch forests showed similar patterns; however, an increase in the active layer thickness and permafrost thaw at some sites have eradicated the transition zone, and the large ice lenses encountered at depth reflect segregated ground ice developed during initial downward aggradation of permafrost. Our findings indicate that white spruce/birch terrain will be less sensitive than black spruce forests to near‐surface permafrost thaw. However, if permafrost thaws completely, white spruce/birch terrain will probably be transformed into wetland–thaw lake complexes due to high ground ice content at depth.
Parametric Lyapunov equation based event‐triggered and self‐triggered control of input constrained linear systems
Authors: Zhang Kai , Zhou Bin , Jiang Huaiyuan 
Published: September 2020

SummaryThis article studies semiglobal stabilization of input constrained linear systems based on the static and dynamic event‐triggered control (ETC) and self‐triggered control (STC). First, a static ETC based on the parametric Lyapunov equation (PLE) is designed. Then the corresponding dynamic ETC is also proposed. The main advantage of the proposed static and dynamic ETC algorithms is that the minimum interexecution time (MIET) as a decreasing function of the parameter in the PLE is given, which allows us to find easily a trade‐off between the interexecution times (IETs) and the control performance. The fact that the MIET of the dynamic ETC is never less than that of the static ETC is also guaranteed. Next, in order to avoid continuous monitoring of the states, both static and dynamic STC are designed. The influence of the parameters on IETs of the static and dynamic STC is analyzed in detail. The nonoccurrence of the Zeno phenomenon is proved in all the control algorithms. Finally, the proposed algorithms are applied to the design of spacecraft rendezvous. Numerical simulations on the original nonlinear model of the spacecraft rendezvous control system show the control system effectiveness of the algorithms.
What Constitutes a Science of Reading Instruction?
Authors: Shanahan Timothy 
Published: September 2020

ABSTRACTRecently, the term science of reading has been used in public debate to promote policies and instructional practices based on research on the basic cognitive mechanisms of reading, the neural processes involved in reading, computational models of learning to read, and the like. According to those views, such data provide convincing evidence that explicit decoding instruction (e.g., phonological awareness, phonics) should be beneficial to reading success. Nevertheless, there has been pushback against such policies, the use of the term science of reading by “phonics‐centric people”, and their lack of instructional knowledge and experience. In this article, although the author supports pedagogical decision making on the basis of a confluence of evidence from a variety of sources, he cautions against instructional overgeneralizations based on various kinds of basic research without an adequate consideration of instructional experiments. The author provides several examples of the premature translation of basic research findings into wide‐scale pedagogical application.
Removal of Mercury Ions from Aqueous Solutions by Crosslinked Chitosan‐based Adsorbents: A Mini Review
Authors: Zhang Dan , Crini Grégorio , Lichtfouse Eric , Rhimi Baker , Wang Chuanyi 
Published: September 2020

AbstractAbatement of mercury emissions in air and waters has become a global challenge due to the toxicity of mercury species for life, yet actual remediation techniques are limited. In particular, adsorption of mercury ions onto solids is widely used but most adsorption techniques are not specific, and in turn, removal efficiency is lower. Adsorbents developed so far include activated carbon, clay, bentonite, cellulose and chitosan. Chitosan derivatives have recently attracted research attention for water purification because their molecular frames contain a large amount of −NH2 and −OH groups that can chelate with metal ions specifically. This manuscript reviews recent advances in chitosan‐based adsorbents designed to remove mercury ions from wastewater. Focus is placed on their design, synthesis, characterization, adsorption properties, adsorption mechanisms and applications.
Stability of Poiseuille flow in an anisotropic porous layer with oblique principal axes: More accurate solution
Authors: Shankar B.M. , Shivakumara I.S. 
Published: September 2020

AbstractThe stability of fluid flow in an anisotropic porous medium of Brinkman type is investigated. Anisotropy in the permeability is considered such that its longitudinal principal axis is oriented arbitrarily with the horizontal, while transversely it is isotropic. A fourth‐order eigenvalue problem obtained by performing a linear stability analysis is solved numerically using the Chebyshev collocation and the compound matrix methods. The critical Reynolds number and the critical wave number are computed for different values of porous parameter, orientation angle of the principal axis and the mechanical anisotropy parameter. The porous and the mechanical anisotropy parameters disclose contrasting contributions to the stability of fluid flow. The orientation angle instills either stabilizing or destabilizing effects on the fluid flow depending on the value of anisotropy parameter. Besides, the streamlines of the perturbation modes are presented for various values of orientation angle and anisotropy parameter. For the Darcy case, a simple analytical method is employed and established that the flow is stable for all infinitesimal perturbations.
Integrated Water Resource Management: Principles and Applications
Authors: Meran Georg , Siehlow Markus , von Hirschhausen Christian 
Published: September 2020

AbstractThe concept of Integrated Water Resource Management (IWRM) was established, back in the 1930s, to address “optimal” water management, mainly from a technical perspective, but also taking into account social goals, such as the fulfillment of basic needs and the total welfare of the population. The chapter provides a comprehensive overview of issues related to IWRM. After a discussion of the various economic dimensions of water, we establish a basic model to analyze the value of water under different social welfare objective functions, including the human right to water. The technical-economic model also addresses questions of eco-hydrology, water recycling, groundwater management, and water quality management. The chapter also addresses water allocation along rivers and water transfers between watersheds. The chapter includes exercises and suggestions for further reading.
The EmojiGrid as a Rating Tool for the Affective Appraisal of Touch
Authors: Toet Alexander , van Erp Jan B. F. 
Published: September 2020

AbstractWe evaluated the convergent validity of the new language-independent EmojiGrid rating tool for the affective appraisal of perceived touch events. The EmojiGrid is a rectangular response grid, labeled with facial icons (emoji) that express different degrees of valence and arousal. We previously showed that participants can intuitively and reliably report their affective appraisal of different sensory stimuli (e.g., images, sounds, smells) by clicking on the EmojiGrid, without additional verbal instructions. However, because touch events can be bidirectional and are a dynamic expression of action, we cannot generalize previous results to the touch domain. In this study, participants (N = 65) used the EmojiGrid to report their own emotions when looking at video clips showing different touch events. The video clips were part of a validated database that provided corresponding normative ratings (obtained with a 9-point SAM scale) for each clip. The affective ratings for inter-human touch obtained with the EmojiGrid show excellent agreement with the data provided in the literature (intraclass correlations of .99 for valence and .79 for arousal). For object touch events, these values are .81 and .18, respectively. This may indicate that the EmojiGrid is more sensitive to perspective (sender versus receiver) than classic tools. Also, the relation between valence and arousal shows the classic U-shape at the group level. Thus, the EmojiGrid appears to be a valid graphical self-report instrument for the affective appraisal of perceived touch events, especially for inter-human touch.
Haptic Feedback in a Teleoperated Box & Blocks Task
Authors: Kuling Irene A. , Gijsbertse Kaj , Krom Bouke N. , van Teeffelen Kees J. , van Erp Jan B. F. 
Published: September 2020

AbstractHaptic feedback is a desired feature in teleoperation as it can improve dexterous manipulation. Direct force feedback to the operator’s hand and fingers requires complex hardware and therefore substituting force by for instance vibration is a relevant topic. In this experiment, we tested performance on a Box & Blocks task in a teleoperation set-up with no feedback, direct force feedback and substituted vibration feedback. Objective performance was the same in all conditions as was the learning effect over three sessions, but participants had a clear preference for haptic feedback over no haptic feedback. The preferred type of feedback (force or vibration or both) varied over participants. In general, this study showed that haptic feedback is preferred in teleoperation, the Box & Blocks task seems not sensitive enough for our (and most) current teleoperation set-up(s), and vibration feedback as substitute for direct force feedback works well and can be used intuitively.
The Effects of Simultaneous Multi-point Vibratory Stimulation on Kinesthetic Illusion
Authors: Ushiyama Keigo , Tanaka Satoshi , Takahashi Akifumi , Kajimoto Hiroyuki 
Published: September 2020

AbstractKinesthetic sensation is important for improving presence and immersion in VR environments. However, presenting kinesthetic sensation usually requires a large space so as to avoid users colliding with objects or other users. One of the ways to tackle this issue is to use kinesthetic illusion, which is a way of presenting kinesthetic sensation without physical motion. However, realizing dynamic motion and fast movement remains difficult. Considering that multiple synergist muscles are usually involved in a movement such as walking or even simple arm movement, stimulating multiple synergist muscles might enhance the illusion. Thus, we investigated whether multi-point vibratory stimulation to multiple synergist muscles enhances induced kinesthetic illusions. We found that stimulating multiple synergist muscles created more vivid illusions. Additionally, we found that our method was effective for inducing steady illusions. We also calculated the contribution of each proposed stimulation point to the illusion.
Isometric Force Matching Asymmetries Depend on the Position of the Left Hand Regardless of Handedness
Authors: Ballardini Giulia , Casadio Maura 
Published: September 2020

AbstractSeveral studies highlighted differences in behavioral performance between the two hands, either due to hand dominance or to specialization of the brain hemisphere. In a previous study, right-handed individuals performed a bimanual isometric force-matching task with the arms in different configurations. There we found that the accuracy of the performance depended on the position of the left hand. Matching performance was worse when the left hand was in the lower position, regardless the symmetry of the arm configurations. In the present study, we tested the hypothesis that this effect is related to handedness, i.e., that in both right- and left-handed individuals the performance depends on the position of the non-dominant hand. Left-handed and age-matched right-handed participants were required to apply simultaneously the same amount of force in the upward direction, with the arms in symmetric or asymmetric configurations. No visual feedback of limb positions was provided. We found that for both groups the absolute and the signed (bias) difference of force between the sides depended on the position of the left hand. Thus, this role of the left arm was not determined by handedness, but likely by the specialization of the brain hemisphere. However, handedness influenced the performance: left-handers had a higher absolute error than right-handers in almost all conditions. No main effect of the left hand position was found for the variable error, but left-handers in most configurations had higher variable error when the left hand was in the lower position.
Computational Model of a Pacinian Corpuscle for an Electrical Stimulus: Spike-Rate and Threshold Characteristics
Authors: Vasudevan Madhan Kumar , Ray Rahul Kumar , Muniyandi Manivannan 
Published: September 2020

AbstractUnderstanding the response of Pacinian Corpuscle (PC) for an electrical stimulus through a computational model can give better insight into the physiology. Although there are simpler models available in the literature, models simulating spike-rate and threshold characterizations are still missing. These characterizations may lead to the development of tactile displays combining both electrical and mechanical stimuli, especially high-frequency vibrations. We developed a PC model with equivalent circuits of the electrode-skin interface, PC’s neurite, and the first Ranvier node. The input electrical stimulus is a current pulse with varying amplitude (0 to 2 mA) and varying frequency (5 Hz to 1600 Hz). The model is characterized initially for the frequency response, and then the spike-rate and threshold characteristics were simulated. The spike-rate traces for electrical stimuli show the phase-locking phenomenon similar to the mechanical stimuli responses of PC, however the plateau lengths are larger for the spike-rate traces with electrical stimuli compared to that of the mechanical stimuli. This is reflected as a large difference in the threshold characteristics for one and two impulses-per-cycle. Moreover, threshold characteristics are little influenced by the neural noise. This model can be extended to study the combination of electrical and mechanical stimuli.
Can Stiffness Sensations Be Rendered in Virtual Reality Using Mid-air Ultrasound Haptic Technologies?
Authors: Marchal M. , Gallagher G. , Lécuyer A. , Pacchierotti C. 
Published: September 2020

AbstractMid-air haptics technologies convey haptic sensations without any direct contact between the user and the interface. A popular example of this technology is focused ultrasound. It works by modulating the phase of an array of ultrasound emitters so as to generate focused points of oscillating high pressure, which in turn elicit haptic sensations on the user’s skin. Whilst using focused ultrasound to convey haptic sensations is becoming increasingly popular in Virtual Reality (VR), few studies have been conducted into understanding how to render virtual object properties. In this paper, we evaluate the capability of focused ultrasound arrays to simulate varying stiffness sensations in VR. We carry out a user study enrolling 20 participants, showing that focused ultrasound haptics can well provide the sensation of interacting with objects of different stiffnesses. Finally, we propose four representative VR use cases to show the potential of rendering stiffness sensations using this mid-air haptics.
Soft-Wearable Device for the Estimation of Shoulder Orientation and Gesture
Authors: Contreras-González Aldo F. , Samper-Escudero José Luis , Pont-Esteban David , Sáez-Sáez Francisco Javier , Sánchez-Urán Miguel Ángel , Ferre Manuel 
Published: September 2020

AbstractThis study presents the development of a wearable device that merges capacitive soft-flexion and surface electromyography (sEMG) sensors for the estimation of shoulder orientation and movement, evaluating five natural movement gestures of the human arm. The use of Time Series Networks (TSN) to estimate the arm orientation, and a pattern recognition method for the estimation of the classification of the gesture are proposed. It is demonstrated that it is possible to know the orientation of the shoulder, and that the algorithm is capable of recognising the five gestures proposed with two different configurations. The study is performed on people who reported healthy upper limbs.
A Parallel Elastic Haptic Thimble for Wide Bandwidth Cutaneous Feedback
Authors: Leonardis Daniele , Gabardi Massimiliano , Solazzi Massimiliano , Frisoli Antonio 
Published: September 2020

AbstractDesign of wearable fingertip haptic devices is often a compromise between conflicting features: lightness and compactness, against rich and neat haptic feedback. On one side direct drive actuators (i.e. voice coils) provide a clean haptic feedback with high dynamics, with limited maximum output forces. On the other side mechanical transmissions with reduction can increase output force of micro sized motors, at the cost of slower and often noisy output signals. In this work we present a compact fingertip haptic device based on a parallel elastic mechanism: it merges the output of two differently designed actuators in a single, wide bandwidth haptic feedback. Each actuator is designed with a different role: one for rendering fast, high frequency force components, the other for rendering constant to low frequency components. In the work we present design and implementation of the device, followed by experimental characterization of its performance in terms of frequency response and rendering capabilities.
Instrumenting Hand-Held Surgical Drills with a Pneumatic Sensing Cover for Haptic Feedback
Authors: Gaudeni Chiara , Lisini Baldi Tommaso , Achilli Gabriele M. , Mandalà Marco , Prattichizzo Domenico 
Published: September 2020

AbstractDespite the recent achievements in the development of open surgery tools, preserving the haptic capabilities during drilling tasks is still an open issue. In this paper, we propose a novel tool for hand-held drills composed of a cover for force sensing and a haptic display for force feedback. A pneumatic device has been developed to estimate the contact force occurring during the interaction between drill bit and bones. A performance comparison with a precise commercial force sensor proved the reliability of the measurements. A haptic ring is in charge of providing cutaneous sensations helping the surgeon in performing the task. The effectiveness of our method has been confirmed by experimental results and supported by statistical analysis.
Rendering Ultrasound Pressure Distribution on Hand Surface in Real-Time
Authors: Matsubayashi Atsushi , Makino Yasutoshi , Shinoda Hiroyuki 
Published: September 2020

AbstractIn this paper, we propose a method for rendering the pressure distribution on the skin surface of a hand in real-time using an ultrasonic phased array. Our method generates a polygon mesh model representing the hand shape by fitting a rigid template to the point cloud captured by depth sensors. Obtaining the entire hand shape as a mesh model enables to solve scattering problem to generate a precise distribution on the hand surface. Therefor, for example, our method can control the width of the distribution on the fingertip according to the size of the contact area with the virtual object. We have experimentally verified that considering the scattering on the mesh model contributes to accurate pressure pattern reproduction.
Midair Tactile Reproduction of Real Objects
Authors: Sakiyama Emiri , Matsubayashi Atsushi , Matsumoto Daichi , Fujiwara Masahiro , Makino Yasutoshi , Shinoda Hiroyuki 
Published: September 2020

AbstractMidair tactile display using ultrasound radiation pressure is suitable for tactile reproduction because of its reproducibility and controllability. This paper is the first report that compares the tactile feelings of real objects with those associated with artificial stimuli reproduced through a sequence of sensing, processing, and reproduction. We previously proposed the concept of a midair tactile reproduction system and examined the basic properties of the sensing part, but had not achieved the tactile display to the human skin. In this paper, we report a practical method for the pressure reproduction from the measured data and examine the accuracy of the reproduced stimulation. The psychophysical experiments evaluate the fidelity of the tactile reproduction for some objects such as brushes, sponges, and towels.
Motion Guidance Using Translational Force and Torque Feedback by Induced Pulling Illusion
Authors: Tanabe Takeshi , Yano Hiroaki , Endo Hiroshi , Ino Shuichi , Iwata Hiroo 
Published: September 2020

AbstractIt is known that humans experience a kinesthetic illusion similar to a pulling sensation in a particular direction, when subjected to asymmetric vibrations. In our previous study, we developed a device that can apply a translational force and a torque to induce this illusion. The illusory translational force might induce a reaching motion of the upper limb, and the applied torque might induce a flexion–extension motion of the wrist. In the present study, we experimentally verified whether these motions can be induced. The results confirmed that the device could guide the upper limb with a success rate of 94.3% when switching between the application of the translational force and the torque. The results suggested that torque application could be a cue for the user to determine the movement direction intuitively.