bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measuring implicit intergroup biases
Authors: Lai Calvin K. , Wilson Megan E. 
Published: November 2020

AbstractImplicit intergroup biases are automatically activated prejudices and stereotypes that may influence judgments of others on the basis of group membership. We review evidence on the measurement of implicit intergroup biases, finding: implicit intergroup biases reflect the personal and the cultural, implicit measures vary in reliability and validity, and implicit measures vary greatly in their prediction of explicit and behavioral outcomes due to theoretical and methodological moderators. We then discuss three challenges to the application of implicit intergroup biases to real‐world problems: (1) a lack of research on social groups of scientific and public interest, (2) developing implicit measures with diagnostic capabilities, and (3) resolving ongoing ambiguities in the relationship between implicit bias and behavior. Making progress on these issues will clarify the role of implicit intergroup biases in perpetuating inequality.
Ultrasonographic findings of gastrointestinal histoplasmosis in dogs
Authors: Chávez‐Peón Berle Erica , KuKanich Kate , Biller David 
Published: November 2020

AbstractHistoplasmosis, a mycotic infection caused byHistoplasmaspp, can infect the gastrointestinal tract of dogs. Clinical signs of gastrointestinal histoplasmosis can include diarrhea, profound weight loss, anorexia, and vomiting. Rectal scrape for cytology can provide a quick diagnosis, but if negative abdominal ultrasound is often pursued. Ultrasonographic abnormalities in dogs with gastrointestinal histoplasmosis have rarely been reported. This retrospective, single‐center case series aimed to describe the ultrasonographic features of gastrointestinal histoplasmosis in dogs. Nineteen cases with a diagnosis of gastrointestinal histoplasmosis confirmed with gastrointestinal cytology or histopathology (N = 15) or gastrointestinal lymph node cytology (N = 4) that had undergone an abdominal ultrasound examination from 2005 to 2020 were included. Ultrasound images were reviewed by an American College of Veterinary Radiology (ACVR)‐certified veterinary radiologist and diagnostic imaging resident. Eighteen cases had sonographic abnormalities within the gastrointestinal tract. The colon was the most affected organ. Colonic thickening and abnormal wall layering were the most frequent findings (N = 16 dogs); thickening ranged from 0.36 to 1.2 cm. Diffuse, multifocal, and focal thickening patterns were seen. Sixteen patients had abnormal wall layering of the colon (complete loss of layering or altered with partial loss of layering). Other frequent findings included lymphadenopathy, small intestinal thickening with abnormal wall layering and peritoneal effusion. Based on the authors’ review of the literature, this is the first description of ultrasonographic findings of gastrointestinal histoplasmosis in a group of dogs. Although abnormal gastrointestinal wall layering seen sonographically is most frequently associated with neoplasia, this is not pathognomonic. Gastrointestinal histoplasmosis should be considered as a differential diagnosis due to the similarities and overlap of ultrasonographic features.
Modeling and Parametric Analysis of Multilayer Piezocomposite Actuators
Authors: Wright Cody , Bilgen Onur 
Published: November 2020

Abstract
Design space for morphing structures using single layer commercial piezocomposite actuators are often restricted due to limitations in actuation authority. Optimal designs are those in which the substrate-actuator composite is stiff enough to maintain shape when subjected to surface pressures but allow for the desired curvature under excitation. This trade-off limits substrate to actuator thickness ratios in applications where dynamic pressures are high. One way to improve actuation authority while maintaining stiffness is to use multiple piezocomposite actuators. This paper explores the benefits and drawbacks of using multilayer piezocomposite actuators. The actuators are modeled using the finite element method and are characterized using well-known free strain and blocked force conditions in a four-point loading condition. Material properties for substrate, piezocomposite, and glue layers are modeled based on previous experimental analysis of curvature over a range of thickness ratios for single element actuators. A parametric analysis is conducted on multilayer piezocomposites varying thickness ratio, substrate material and number of piezocomposite layers. Results for the parametric analysis are presented in the form of maximum curvature, work done, and work done normalized by number of layers. A discussion of new design space potential for multilayer actuators is provided.
A Method of Crack Monitoring for Electrically Activated SMA Wires Using Thermography
Authors: Theren Benedict , Kuhlenkötter Bernd , Schuleit Marvin , Esen Cemal 
Published: November 2020

Abstract
Predicting the remaining lifetime of an operating shape memory actuator is a great goal to achieve to increase its reliability. The shape memory wires used in these actuators are mostly activated using Joule Heating. Therefore the electrical resistance during activation can easily be measured. Studies show an increase in electrical resistance with an increasing number of activations due to fatigue. Therefore monitoring the electrical resistance leads to a prediction regarding the remaining lifetime of the actuator. The electrical resistance depends on the ambient temperature and the load case (yielded stress, activation frequency, voltage, and current) resulting in different maximum activation temperatures of the wire. The increase in electrical resistance should lead to a higher wire temperature. Before the wire fails due to fracture cumulating cracks should appear. These cracks decrease the diameter of the wire that leads to locally increased electrical resistance and therefore a local higher temperature. This work investigates if those hotspots can be monitored using thermal imaging. Binary Ni50Ti50 wires with a diameter of 0.28 mm were investigated. Measuring the exact temperature of the wires is difficult since the specimens are round and the emission coefficient is unknown. Therefore only qualitative measurement of the temperature is performed.
10 experiments at different stresses and voltages were performed. The results show some indications, that the position and the moment of the fracture can be determined using this setup. Several models are matching the wire temperature after activation to its fracture strength and fatigue behavior. Further investigations must be performed combining the presented models to the results of this work.
Design and Testing of a Lattice Morphing Wing
Authors: Keidel Dominic , Lienhard Marc , Fasel Urban , Ermanni Paolo 
Published: November 2020

Abstract
This work presents the design, optimization and testing of a novel lattice-structure based morphing wing. The lattice-structure concept spans a large design space, including the possibility to vary among others material, number, distribution and the orientation of the lattice rods. The used parametrization scheme considers both the positioning of the Carbon Fiber Reinforced Polymer (CFRP) rods and their orientation in spherical coordinates within the wing, thus allowing to appropriately cover the design space, while reducing the set of variables during the design optimization procedure. The morphing deformations are relying on electromechanical servomotors. Design objectives include weight minimization and structural requirements, while achieving sufficient roll control.
The local deformation induced by the electromechanical actuators is distributed by an internal skeleton structure across the rear section of the wing. An extensible skin is ensuring a smooth cambering and minimizes the required actuation energy. The in-house developed and validated simulation environment couples the aerodynamic pressure and the structural deformations, to accurately predict the aeroelastic response of the wing to aerodynamic and actuation forces, considering large deformations. In addition to the lattice structure, the aeroelastic optimization also considers the actuation layout, and the layup-thickness of the wing skin. Planform and airfoil shape are fixed to a NACA0012 airfoil with 80 cm span, and 30 cm chord.
The structural and morphing behavior was evaluated on a technology demonstrator. The demonstrator provides large continuous shape changes, improving the aerodynamic performance and achieving large deflections and high rolling moment coefficients. This is mainly achieved by exploiting the interaction of the tailored internal structure and the actuation system. Since the deformation is distributed over a large portion of the wing, local stress concentrations are minimized, and actuation forces are reduced. Wing-up bending tests have been carried out, confirming the simulation results, respectively the load-carrying capability of the presented concept. Furthermore, actuation tests resulted in peak-to-peak trailing edge deflections of 31mm, respectively a rolling moment coefficient of 0.062, which are consistent with the simulation results and guarantee sufficient roll control.
Investigation and Attempt to 3D Print Piezoelectric 0-3 Composites Made of Photopolymer Resins and PZT
Authors: Mitkus Rytis , Pierou Andreas , Feder Julia , Sinapius Michael 
Published: November 2020

Abstract
The present study demonstrates the manufacturing and characterization of 0-3 piezoelectric composites made of up to 10 vol% of Lead Zirconate Titanate (PZT) particles and photopolymer resins. The tape-casting method was used to investigate the curing behavior, PZT loading limitations and the overall feasibility of the suspensions for 3D printing. Piezoelectric composites were 3D printed with a commercial DLP type 3D printer. As a starting point, the maximum possible vol% loading of PZT ceramic for each photopolymer resin was investigated. Five different commercially available photopolymer resins from Formlabs (Somerville, MA, US) were used. It was found that the addition of PZT particles to the photopolymer increases the time required for the photopolymer to solidify because PZT particles scatter the UV light. The approximate solidification time of each composition was measured, followed by viscosity measurements. SEM imaging of the composites showed good particle dispersion with minimum agglomeration, low particle sedimentation, but the weak bond between PZT particles and the photopolymers. Best performed material composition with 10 vol% of PZT was used for 3D printing. An attempt to shorten exposure time during printing was done by adding photoinitiator TPO. Suspensions with and without TPO were 3D printed and compared.
On the Effects of Electrical Conductivity on the Triboelectric Behavior of a PDMS-Based Composite Material
Authors: Zhao Xiaoyue , Dhanani Jai , Ounaies Zoubeida , Rashwan Ola 
Published: November 2020

Abstract
With the increasing demand for small and portable electronic devices, new energy conversion systems that can harvest energy from body motion and ambient environment are needed. Triboelectricity has recently become promising among the various energy conversion mechanisms because triboelectric devices can be small, flexible, and portable. The triboelectric output performance is closely related to the materials ‘properties employed. In this study, the effect of electrical conductivity on the electrical output of a triboelectric device is investigated experimentally. Experiments are conducted using a vertical contact/separation mode with polydimethylsiloxane (PDMS) based material as one of the contacting materials. The electrical conductivity of PDMS is tuned by adding two different weight percent of multiwall carbon nanotube (CNT): 10wt% CNT and 20wt% CNT. The relationship between electrical conductivity and the triboelectric output performance is obtained by correlating the open circuit voltage (Voc) and short circuit current (Isc) with the different weight percent CNT-PDMS materials. A maximum Voc of 98V and a maximum Isc of 3.2μA were obtained with the 20wt% CNT-PDMS and Teflon pair; this increase is likely due to the combination of enhanced triboelectric polarity difference and electrical conductivity. The optimum external resistance was also measured for the different CNT-PDMS weight percent materials. The maximum triboelectric output power reached 180μW at 80MΩ for the 20wt% CNT-PDMS and Teflon pair.
Magnetorheological Damper With Micro-Grooves: Design and Experiment
Authors: Liu Gaoyu , Gao Fei , Liao Wei-Hsin 
Published: November 2020

Abstract
Due to low power consumption and fast response, magnetorheological (MR) dampers are widely used in various engineering applications. To enhance the performances, efforts have been made to increase the field dependent force with the same power consumption. However, the fluid viscous force is also increased significantly, which is undesirable in practical use. To tackle this problem, the focus of this paper is to design and test a new MR damper with micro-grooves for performance enhancement.
First, the detailed design of the proposed MR damper is provided. A prototype of the new MR damper is fabricated. Silicon steel circular rings with thickness of 0.25 mm are installed around the damper piston to form two-layer micro-grooves. Experimental results of the two MR dampers without and with micro-grooves are then compared.
The advantages of MR damper with micro-grooves over the one without micro-grooves are validated. The damping force and controllable force range of MR damper with micro-grooves are larger than the one without micro-grooves. When designing MR damper, making micro-grooves can also decrease the increment of fluid viscous force while keeping the same increase of field dependent force. With micro-grooves, the field dependent force is increased by 92.7% with the same power consumption, while the fluid viscous force is increased by 43%.
Additively Manufactured Continuous Fibre-Reinforced Thermoplastics for Mechanisms Subjected to Predominant Inertial Load: A Case Study
Authors: Luzi Luca , Quercioli Giacomo , Pucci Riccardo , Bocchieri Guido , Vertechy Rocco , Berselli Giovanni 
Published: November 2020

Abstract
In the last decade, the adoption of additive manufacturing technologies (AMT) (3D printing) has increased significantly in many fields of engineering, initially only for rapid prototyping and more recently also for the production of finished parts. With respect to the long-established material subtractive technologies (MST), AMT is capable to overcome several limitations related to the shape realization of high-performance mechanical components such as those conceived via topology optimization and generative design approaches.
In the field of structures and mechanisms, a major advantage of AMT over MST is that, for the same loading and constraining conditions (including kinematic and overall encumbrance), it enables the realization of mechanical components with similar stiffness but smaller volume (thus smaller weight, density being equal).
Recently, the potentialities of AMT have also been increased by the introduction of the fuse filament deposition modeling (FDM) of continuous fibre-reinforced thermoplastics (CFRT), which combines the ease of processing of plastic AMT with the strength and specific modulus of the printed components that are comparable to those attainable via metallic AMT.
In this context, the present paper investigates the potentialities of FDM-CFRT for the realization of mechanisms subjected to predominant inertial loads such as those found in automated packaging machinery. As a case study a Stephenson six-bar linkage powered in direct drive by a permanent magnet synchronous motor is considered. Starting from an existing mechanism realized in aluminum alloy with traditional MST, a newer version to be realized with FDM-CFRT has been conceived by keeping the kinematics fixed and by redesigning the links via three-dimensional topology optimization. To provide a fair comparison with the more traditional design/manufacturing approach, size optimization of the original mechanism made in aluminum alloy has also been performed.
Comparison of the two versions of the mechanism highlights the superior performances of the one manufactured via FDM-CFRT in terms of weight, motor torque requirements and motion precision.
Analytical Modeling of a Segmented Bimorph Lithium Ion Battery Actuator
Authors: Gonzalez Cody , Shan Shuhua , Frecker Mary , Rahn Christopher 
Published: November 2020

Abstract
Silicon composite anode-based lithium ion battery actuators have strong potential for large actuation strain, complex shape change, and large compliance tunability. This allows for actuators with potential to do work with no energy expenditure beyond parasitic losses to internal resistance. This paper studies a segmented bimorph actuator comprised of a silicon-based composite anode double-side coated on copper foil.
The bimorph design allows for a nearly 360° range of motion in transverse bending and can double the capacity of the battery in comparison to a single side coated unimorph design. An Euler-Bernoulli model is developed to predict free deflection for a range of geometric configurations and states of charge of the bimorph. By modeling the charging of both active sides of the bimorph simultaneously, it is possible to achieve zero bending while still accommodating for the volumetric expansion of the silicon. The bimorph is able to achieve actuation in one given direction by charging each anode coating separately or maintaining a charge difference between the two coatings. The former method allows for the accommodated volumetric expansion of silicon while maintaining zero bending as in a conventional battery setup. The latter method allows for larger battery capacity and range of motion for a novel electrochemically-based actuation mechanism.
Analysis of Multi-Stable Architectures for Morphing Structures
Authors: Erol Anil , Baur Jeffery 
Published: November 2020

Abstract
The field of multi-stable structures has been steadily growing due to a wide range of potential applications including energy harvesting, MEMS, and mechanical logic. This work focuses on utilizing elastic energy trapping and snap-through phenomena of bistable unit cells to design a latticed, hierarchical multi-stable cylinder that can articulate up to 30 degrees from its center axis. The employment of bistable elements is hypothesized to reduce the total strain energy required to articulate the cylinder, and yield faster responses with the snap-through. While multi-stable cylinders exist in previous studies, there have been no previous attempts at studying different modes of deformation beyond compressive loading. Thus, the current work presents a new problem regarding the effects of bistable elements in a latticed cylinder that is carrying tensile, compressive, and shear loadings and exhibiting large displacements as the cylinder is articulated.. The total strain energy density of the articulating cylinder is investigated as a function of the heights of the unit cells, which aids in determining an ideal height for the design that minimizes the strain energy density. Results show that the strain energy of an articulating cylinder can be minimized with the use of multi-stability, and that a multi-stable cylinder can require up to three times less loads to maintain desired articulation compared to a mono-stable structure. These results will lead to future works on further optimizing the articulating cylinder by varying additional parameters like the individual heights of rows, the thicknesses of unit cell beams, the strain energy density, and the initial loading threshold for articulation. In addition, the work in this study can yield methodologies for designing arbitrarily morphing skins beyond just cylindrical geometries.
A Lumped Parameter Approach for Analysing a Metamaterial Beam Based Piezoelectric Energy Harvester Around Fundamental Resonance
Authors: Hu Guobiao , Tang Lihua , Yang Yaowen 
Published: November 2020

Abstract
This paper proposes a lumped parameter approach to simplify the modelling of a metamaterial based PEH to predict its energy harvesting performance around the fundamental resonance. The metamaterial based PEH consists of a host beam with a piezoelectric patch bonded at the clamped end. A series of local resonators are attached onto the host beam. In the first case study, the local resonators are modelled as mass-spring systems. By applying Rayleigh’s method and approximating the fundamental mode shape by the static deflection, the host beam is represented by a SDOF system. The equivalent lumped parameters are assumed to concentrate at the tip of the host beam and their explicit expressions are presented. Though the local resonators are identical, they have different influences on the host beam when being attached at different positions. To reflect the interaction degree (i.e., reacting force) between the local resonator and the host beam, a scaling factor that is a function of the attaching position is derived. On the other hand, due to the action of the local resonators, the fundamental mode shape of the host beam is actually changed. Based on the linear superposition principle, the static deflection approximated fundamental mode shape is corrected and the electromechanical coupling coefficient that is sensitive to the slope of the mode shape is updated to improve the accuracy. Based on the derived equivalent lumped parameters and correction factors, a multiple-degree-of-freedom (MDOF) model is constructed to predict the dynamic behavior of the metamaterial based PEH with mass-spring resonators. A corresponding finite element model is built to verify the developed MDOF model. In the second case study, the local resonators are modelled as practical parasitic beams. The parasitic beams are converted into equivalent lumped systems as well. However, the lumped parameters are the effective parameters at the beam tip. For the force interaction at the root of a parasitic beam, a factor is derived to correct the reaction force when a parasitic beam is represented by a SDOF mass-spring system. Using the reaction force correction factor, a MDOF model for the metamaterial based PEH with beam-like resonators is also established and verified by the finite element model.