bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Investigation of the Mechanisms and Performance of Active Auxetic and Shearing Textiles
Authors: Granberry Rachael , Holschuh Brad , Abel Julianna 
Published: December 2019

Abstract
Anisotropic textiles are commonly used in wearable applications to achieve varied bi-axial stress-strain behavior around the body. Auxetic textiles, specifically those that exhibit a negative Poisson’s ratio (v), likewise exhibit intriguing behavior such as volume increase in response to impact or variable air permeability. Active textiles are traditional textile structures that integrate smart materials, such as shape memory alloys, shape memory polymers, or carbon nanotubes, to enable spatial actuation behavior, such as contraction for on-body compression or corrugation for haptic feedback. This research is a first experimental investigation into active auxetic and shearing textile structures. These textile structures leverage the bending- and torsional-deformations of the fibers/filaments within traditional textile structures as well as the shape memory effect of shape memory alloys to achieve novel, spatial performance. Five textile structures were fabricated from shape memory alloy wire deformed into needle lace and weft knit textile structures. All active structures exhibited anisotropic behavior and four of the five structures exhibited auxetic behavior upon free recovery, contracting in both x- and y-axes upon actuation (v = −0.3 to −1.5). One structure exhibited novel shearing behavior, with a mean free angle recovery of 7°. Temperature-controlled biaxial tensile testing was conducted to experimentally investigate actuation behavior and anisotropy of the designed structures. The presented design and performance of these active auxetic, anisotropic, and shearing textiles inspire new capabilities for applications, such as smart wearables, soft robotics, reconfigurable aerospace structures, and medical devices.
DfAM of Nonlinear Cellular Flexible Structures
Authors: Djokikj Jelena , Jovanova Jovana 
Published: December 2019

Abstract
Nonlinear cellular structures are defined as structures with multiple scale unit cells patterned through the volume of the structure. The geometrical nonlinearity allows local high flexibility in the movement and also in the sense of strength of materials.
The focus of this paper is to create a framework for design for additive manufacturing (DfAM) of a modular nonlinear cellular structure with high level of flexibility. The flexibility will be exploited in skin-like structures adaptable to freeform geometries or utilize flat printed designs for voluminous and structural 3D shapes.
For the modeling of the structure CAD software is used and for the fabrication of the structure additive manufacturing (AM) is applied. These technologies work by adding the material in layers, which enables fabrication of parts with complex geometries. The working principal of AM which is opposite to the traditional manufacturing requires for changes in the design process. These changes are applied in the DfAM that we are presenting with this study. The DfAM is used to develop a systematic design approach to support the fabrication of unique structure shapes by AM.
Experimental Studies of the Actuation of Carbon Nanotube-Based Materials
Authors: Geier Sebastian , Mahrholz Thorsten , Wierach Peter , Sinapius Michael 
Published: December 2019

Abstract
Carbon nanotubes (CNTs) show an active behavior when they are positioned within an electric field, immersed into an electrolyte and charged. Several explanations are given, ranging from nanoscopic to macroscopic effects. This paper presents experimental proven explanations of the paper actuation and results using continuous CNTs of a CNT-array.
For the first test series specimens are cut off a paper manufactured of single-walled, μ-long CNTs working in series. The second test series uses specimens which are prepared of free standing multi-walled CNTs. Their CNT lengths reach macroscopic dimensions of almost 3 mm and they can be considered as connected in parallel. Both series are electromechanically tested.
The paper tests reveal their strong condition-dependent microstructure. Generally, the observed effects can be explained by diffusion of ions into the flexible CNT microstructure.
In contrast, the CNT-array based specimens show almost no condition dependency which can be explained by the strong carbon bonds. Due to specimen orientation and test set-up, macroscopic effects can be excluded. The found actuation can be attributed to an elongation of the carbon structure as result of ion-interaction. However, it must be assumed that there are further superimposing effects which might not be distinguished from each other down to the last detail.
Structure Integrated Supercapacitors for Space Applications
Authors: Geier Sebastian , Petersen Jan , Wierach Peter 
Published: December 2019

Abstract
The increasing electrification places great demands on the supply and storage of electrical energy. Beside batteries, supercapacitors are a second storage technology with clear advantages compared to batteries in terms of charging time, energy density and cycle stability.
This publication deals with the structurally compliant integration of pouch supercapacitor cells which are developed for integration into fiber-reinforced composites. The energy storage components are designed to transmit mechanical stresses. The aim is to qualify a space structure with integrated supercapacitors for use under space conditions. For a special peak power application, 14 supercapacitors are integrated into the lay-up of a glass fiber-reinforced structure. This structure connects electronic components and is therefore designed load-bearingly.
Thermal cycling under high vacuum between −22°C and +67°C shows temperature effects, as result of the temperature dependence of the ion mobility. During the other mechanical tests (sinus vibration, random vibration, pyroshock) and irradiation with a Co60 source the electrical performance keeps at the same level.
The structure featuring 14 integrated supercapacitors exhibits a specific capacitance of 1.12 F/g compared to a specific capacitance of 0.35 F/g of a structure using 16 commercial supercapacitors (FastCap EE350). These results demonstrate the great weight- and volume-saving potential of this approach.
Coupled Electro-Thermo-Mechanical Modeling of Shape Memory Polymers
Authors: Siwakoti Midhan , Mailen Russell W. 
Published: December 2019

Abstract
Shape memory polymers (SMPs) are extensively studied for self-folding origami due to their large strain recovery, low cost, and low activation energy. SMPs utilize viscoelastic material behavior to change shape in response to an applied stimulus, for instance light or electricity. Electrical actuation is desirable due to its higher energy density and shorter response time. Previous studies reported empirical results on shape recovery of conductive polymer composites actuated by specific applied voltage or current conditions, which required rigorous experimentation. Here, we introduce a finite element framework capable of predicting the coupled electro-thermo-mechanical response of electrically actuated SMPs. As inputs, this framework requires material properties, such as electrical conductivity and viscoelastic parameters. The viscoelastic response is implemented using a Prony series model that is fit to experimental dynamic mechanical analysis (DMA) data. Using this framework, we predict the shape recovery behavior of electrically actuated SMPs subject to various thermal, electrical, and mechanical loads and evaluate the sensitivity of the response to the material properties. Additionally, we show the effects of material pre-straining conditions and localized conductive pathways on shape recovery and self-folding. This computational framework provides a fundamental understanding of the electro-thermo-mechanical response of electrically actuated SMPs and can be used to design electrically actuated self-folding origami for aerospace applications.
Structural Health Monitoring of Composite Structures via Machine Learning of Mechanoluminescence
Authors: Gupta Sujasha , Krishnan Srivatsava , Sundaresan Vishnubaba 
Published: December 2019

Abstract
The goal of this paper is to develop a machine learning algorithm for structural health monitoring of polymer composites with mechanoluminescent phosphors as distributed sensors. Mechanoluminescence is the phenomenon of light emission from organic/inorganic materials due to mechanical stimuli. Distributed sensors collect a large amount of data and contain structural response information that is difficult to analyze using classical or continuum models. Hence, approaches to analyze this data using machine learning or deep learning is necessary to develop models that describe initiation of damage, propagation and ultimately structural failure.
This paper focuses on developing a machine learning algorithm that predicts the elastic modulus of a structure as a function of input parameters such as stress and measured light output. The training data for the algorithm utilizes experimental results from cyclical loading of elastomeric composite coupons impregnated with ML particles. A multivariate linear regression is performed on the elastic modulus within the training data as a function of stress and ML emission intensity. Error in predicted elastic modulus is minimized using a gradient descent algorithm. The machine learning algorithm outlined in this paper is expected to provide insights into structural response and deterioration of mechanical properties in real-time that cannot be obtained using a finite array of sensors.
Strain Mapping and Large Strain Measurement Using Biaxial Skin Sensors
Authors: Donica Thomas , Gray Jonathan , Zegeye Ephraim F. 
Published: December 2019

Abstract
Electronic skins, or e-skins, are electronic devices capable of sensing physical interactions such as strain, temperature, or pressure. These e-skins are of interest in a variety of fields including robotics, structural health monitoring, and medicine. E-skins should measure strains over a larger range of elongation than traditional strain sensors could. This paper explores the synthesis of a flexible biaxial strain sensor for large surface strain measurement. The sensor is made by spraying an exfoliated graphite and latex mixture onto a latex substrate to form a 4 × 4 grid of electrically conductive strips. Electrodes are connected to each sensor to collect data on deformation induced voltage difference. Two setup geometries were characterized, the behavior of a single strip in each direction in a one by one configuration as well as the behavior of a four by four setup that can measure a two-dimensional strain field. The characteristics of the sensor is studied by attaching it on a tensile testing specimen. When the sensor is subjected to strain along one or both of the two measurement axes, the voltage difference can be recorded using Arduino. The voltage drop was normalized and used to construct a strain distribution plot in MATLAB to determine the highly strained location. In addition to characterizing the behavior of the sensor, the dispersion of the exfoliated graphite in the latex is also studied using optical microscopy. The sensor is made from inexpensive materials and was able to measure large strain that cannot be achieved with commercially available strain gauges.
Investigation of Variable Stiffness Effects on Radial Pulse Measurements Using Magneto-Rheological Elastomers
Authors: Weaver Kyle , Shumway Dylan , Yang Tae-Heon , Kim Young-Min , Koo Jeong-Hoi 
Published: December 2019

Abstract
Current wearable technologies strive to incorporate more medical functionalities in wearable devices for tracking health conditions and providing information for timely medical treatments. Beyond tracking of a wearer’s physical activities and basic vital signs, the advancement of wearable healthcare devices aspires to continuously monitor health parameters, such as cardiovascular indicators. To properly monitor cardiovascular health, the wearables should accurately measure blood pressure in real-time. However, current devices on the market are not validated for continuous monitoring of blood pressure at a clinical level. To develop wearable healthcare devices such applications, they must be validated by considering various parameters, such as the effects of varying skin properties. Being located between the blood vessel and the wearable device, the skin can affect the sensor readings of the device. The primary goal of this study is to investigate the effect of skin property on the radial pulse measurements. To this end, a range of artificial vein-inserted skin samples with varying properties is fabricated using Magneto-Rheological Elastomers (MRE), materials whose mechanical properties can be altered by external magnetic fields. The samples include layers to simulate the structure of skin and a silicone vein for the pulse to pass through. Note that they are not intended to represent real human skin-vein properties but created to vary a range of stiffness properties to carry out the study. Experiments are performed using a cam system capable of generating realistic human pulse waveforms to pass through the samples. During the indentation testing, the sample is compressed using a dynamic mechanical analyzer (DMA) to record experienced surface pressure, allowing the pulse patterns to be studied. Various samples are used to probe the effects of base resin hardness, iron content, and magnetic field. A pressure sensor incorporated in the cam simulator is used to benchmark the internal pulse pressure of the vein while the DMA indents the sample in order to note the pulse pressures being passed through the sample. Test results show that the properties of the skin influence the resulting pulse behaviors, particularly the ratio of the recorded pulse pressures from the sensor and the DMA.
Preseason Injury Rates in a Division II Football Team Before and After the 2017 NCAA Practice Rule Changes
Authors: Smith John J. , Baer Daniel J. 
Published: December 2019

In 2017, the NCAA implemented rule changes to enhance safety in college football; however, the effect on injury risk remains unclear. The purpose of this study was to observe differences in the number and rate of injuries and time-loss injuries in an NCAA Division II football team during two consecutive preseasons, before and after the rule changes. From 2016 to 2017, we observed a decrease in lower extremity (LE) muscle strains from 1.00 injury/session to 0.55 injuries/session. We also observed a decrease in time-loss LE muscle strains from 0.52 injuries/session in 2016 to 0.20 injuries/session in 2017. After the rule changes, we observed fewer time-loss injuries (14.06% decrease), acute LE strains (45.00% decrease), and time-loss LE strains (61.54% decrease) per preseason practice session. These findings suggest that the rule changes may help reduce both the number and severity of LE muscle strains during preseason football.
Cohort profile: the Australian Longitudinal Study of Adults with Autism (ALSAA)
Authors: Arnold Samuel , Foley Kitty-Rose , Hwang Ye In (Jane) , Richdale Amanda L , Uljarevic Mirko , Lawson Lauren P , Cai Ru Ying , Falkmer Torbjorn , Falkmer Marita , Lennox Nick G , Urbanowicz Anna , Trollor Julian 
Published: December 2019

​PurposeThere is a significant knowledge gap regarding the lives of adults on the autism spectrum. Some literature suggests significant health and mental health inequalities for autistic adults, yet there is a lack of comprehensive longitudinal studies exploring risk factors. Further, most research does not include the perspective of autistic adults in its conduct or design. Here, we describe the baseline characteristics and inclusive research approach of a nationwide longitudinal study.​ParticipantsThe Autism Cooperative Research Centre for Living with Autism’s Australian Longitudinal Study of Adults with Autism (ALSAA) is a questionnaire-based longitudinal study of autistic adults (25+ years old) with follow-up at 2-year intervals. Autistic advisors were involved in each stage of research apart from data analysis. Three questionnaires were developed: self-report, informant report (ie, proxy report) and carers (ie, carer experiences and characteristics).​Findings to dateAn inclusive research protocol was developed and agreed with autistic advisors. Baseline data were collected from 295 autistic adults (M=41.8 years, SD=12.0) including 42 informant responses, 146 comparison participants and 102 carers. The majority of autistic participants (90%) had been diagnosed in adulthood (M=35.3 years, SD=15.1). When compared with controls, autistic adults scored higher on self-report measures of current depression and anxiety. Participant comments informed ongoing data gathering. Participants commented on questionnaire length, difficulty with literal interpretation of forced response items and expressed gratitude for research in this area.​Future plansA large comprehensive dataset relating to autistic adults and their carers has been gathered, creating a good platform for longitudinal follow-up repeat surveys and collaborative research. Several outputs are in development, with focus on health service barriers and usage, caregivers, impact of diagnosis in adulthood, further scale validations, longitudinal analyses of loneliness, suicidal ideation, mental illness risk factors and other areas. Baseline data confirm poorer mental health of autistic adults. The ALSAA demonstrates a working approach to inclusive research.
Observational non-randomised controlled evaluation of the effectiveness of cancer counselling centres: a study protocol
Authors: Lingens Solveigh Paola , Schilling Georgia , Harms Julia , Schulz Holger , Bleich Christiane 
Published: December 2019

IntroductionIn recent years, medical treatment for cancer has improved, thereby increasing the life expectancy of patients with cancer. Hence, the focus in healthcare shifted towards analysing treatments that offer to decrease distress and improve the quality of life of patients with cancer. The psychological burden of patients with cancer originates from all kinds of psychosocial challenges related to diagnosis and treatment. Cancer counselling centres (CCounCs) try to address these concerns. However, the current literature lacks research on the effectiveness of CCounCs. This study aims to assess the effectiveness of CCounCs with regard to distress and other relevant psychosocial variables (quality of life, anxietyand so on).Methods and analysisThis prospective observational study with a non-randomised control group has three measurement points: before the first counselling session (baseline, t0) and at 2 weeks and 3 months after baseline (t1, t2). Patients and their relatives who seek counselling between December 2018 and November 2020 and have sufficient German language skills will be included. The control group will be recruited at clinics and oncological outpatient centres in Hamburg. Propensity scoring will be applied to adjust for differences between the control and intervention groups at baseline. Sociodemographic data, medical data and counselling concerns are measured at baseline. Distress (distress thermometer), quality of life (Short Form-8 Health Survey, European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire-Core 30), anxiety (Generalized AnxietyDisorder-7), depression (Patient HealthQuestionnaire-9) and further psychosocial variables are assessed at all time points. With a total of 787 participants, differences between the intervention and control groups of a small effect size (f=0.10) can be detected with a power of 80%.Ethics and disseminationThe study was registered prior to data collection with the German Registration of Clinical Trials in September 2018. Ethical approval was received by the local psychological ethical committee of the Center for Psychosocial Medicine at the University Medical Centre Hamburg-Eppendorf in August 2018. The results will be published in peer-reviewed journals.Trial registration numberDRKS00015516; Pre-results.
Modelling care quality for patients after a transient ischaemic attack within the US Veterans Health Administration
Authors: Arling Greg , Sico Jason J , Reeves Mathew J , Myers Laura , Baye Fitsum , Bravata Dawn M 
Published: December 2019

ObjectiveTimely preventive care can substantially reduce risk of recurrent vascular events or death after a transient ischaemic attack (TIA). Our objective was to understand patient and facility factors influencing preventive care quality for patients with TIA in the US Veterans Health Administration (VHA).MethodsWe analysed administrative data from a retrospective cohort of 3052 patients with TIA cared for in the emergency department (ED) or inpatient setting in 110 VHA facilities from October 2010 to September 2011. A composite quality indicator (QI score) pass rate was constructed from four process-related quality measures—carotid imaging, brain imaging, high or moderate potency statin and antithrombotic medication, associated with the ED visit or inpatient admission after the TIA. We tested a multilevel structural equation model where facility and patient characteristics, inpatient admission, and neurological consultation were predictors of the resident’s composite QI score.ResultsPresenting with a speech deficit and higher Charlson Comorbidity Index (CCI) were positively related to inpatient admission. Being admitted increased the likelihood of neurology consultation, whereas history of dementia, weekend arrival and a higher CCI score made neurological consultation less likely. Speech deficit, higher CCI, inpatient admission and neurological consultation had direct positive effects on the composite quality score. Patients in facilities with fewer full-time equivalent neurology staff were less likely to be admitted or to have a neurology consultation. Facilities having greater organisational complexity and with a VHA stroke centre designation were more likely to provide a neurology consultation.ConclusionsBetter TIA preventive care could be achieved through increased inpatient admissions, or through enhanced neurology and other care resources in the ED and during follow-up care.