bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physiological substrates of imagination in early childhood
Authors: Thibodeau‐Nielsen Rachel B. , Turley Danielle , DeCaro Jason A. , Gilpin Ansley T. , Nancarrow Alexandra F. 
Published: January 2021

AbstractRecent research suggests that imagination, defined as engaging in behaviors or cognitions not representative of one's current reality, is related to the development of emotion regulation (ER) skills in early childhood. Yet, the underlying mechanisms responsible for driving this relationship are unknown. The present study aimed to elucidate one potential pathway through which imagination may influence ER by examining the possible physiological substrates of imagination in early childhood. Specifically, one theoretical perspective proposes that imagination may be related to ER because it allows children to become absorbed in highly emotional, imaginative scenarios, leading to physiological arousal that must be regulated. To support this idea, we must first investigate if imagination evokes a physiological response. To date, no studies have examined physiology during imagination in early childhood. Therefore, the present study included 44 preschool‐aged children who participated in a standard reactivity protocol where physiological responses to mild social, cognitive, sensory, emotional, and imaginative challenges were assessed. Results demonstrated a significant increase in sympathetic nervous system activity when children engaged in a cognitive imaginative storytelling task, even after controlling for overall arousal and task engagement. As the first study to identify a meaningful physiological response during imagination, these data provide one potential explanation for why imagination is related to ER skills in early childhood.
An Experimental and Modeling Strategy for Obtaining Complete Characteristic Maps of Dual-Volute Radial Inflow Turbines
Authors: Serrano José Ramón , Arnau Martínez Francisco José , García-Cuevas Luis Miguel , Samala Vishnu , Guilain Stephane , Batard Samuel 
Published: January 2021

Abstract
Despite the importance of turbocharged engines with dual-volute turbines, their characteristic maps and fully predictive modeling using 1D gas dynamic codes are not well established yet. The complexity of unsteady flow and the unequal admission of these turbines, when operating with pulses of engine exhaust gas, makes them a challenging system. This is mainly due to the unequal flow admission, which generates an additional degree-of-freedom with respect to well-known single entry vanned or vaneless turbines. This paper has as the main novelty a simple procedure for characterizing experimentally and elaborating characteristic maps of these turbines with unequal flow conditions. This method of analysis allows for easy interpolation within the proposed characteristic maps or conceiving simple models for calculating and extrapolating full performance parameters of dual-volute turbines. Two innovative 0D mean-line models are described that require a minimum quantity of experimental data for calibrating both: the mass flow parameter model and the isentropic efficiency model. Both models are predictive either in partial or unequal flow conditions using as inputs: the mass flow ratio and the total temperature ratio between branches; the blade speed ratio and the pressure ratio in each branch. These six inputs are generally instantaneously provided by 1D gas-dynamics codes. Therefore, the novelty of the model is its ability to be used in a quasi-steady way for dual volute turbines performance prediction. This can be done instantaneously when turbines are calculated operating at turbocharged engines under pulsating and unequal flow conditions.
Design Tool for Topology Optimization of Self Supporting Variable Density Lattice Structures for Additive Manufacturing
Authors: McConaha Matthew , Venugopal Vysakh , Anand Sam 
Published: January 2021

Abstract
Additive manufacturing (AM) allows for the inclusion of complicated geometric features that are impractical or impossible to manufacture by other means. Among such features is the collection of intricate and periodic strut-like geometries known as lattice structures. Lattice structures are desirable for their ability to provide stiffness through a large number of supporting members while employing void space within the geometry as a means to reduce part material volume. Strut thicknesses of every lattice in a part are generally not well optimized in order to maximize part stiffness, and often every lattice unit cell is identical throughout the part. This work presents a lattice density optimization methodology that is able to find the optimal graded lattice density distribution for maximizing the part stiffness and also improving the additive manufacturability of the part. The material property interpolation scheme used in SIMP optimization is replaced by a representative volume element (RVE)-based interpolation scheme that more accurately captures the material properties of the prescribed lattice structure at an arbitrary density. A filter has been developed that allows for trimming of unnecessary lattices while simultaneously ensuring that the geometry remains self-supporting during the AM build process. This filter is incorporated seamlessly within the topology optimization routine. This increases the optimality of the resulting design when compared with full-domain lattice filling and increases the viability of the design from a manufacturing standpoint when compared with unconstrained lattice trimming.
Generalized Lévêque Solution for Ducts of Arbitrary Cross Section
Authors: Bennett T. D. 
Published: January 2021

Abstract
The asymptotic limit for perimeter averaged convection is generalized for short ducts of arbitrary cross section. A correction factor to Lévêque's original analysis is derived in terms of the state of wall shear stress under conditions of fully developed flows for walls of constant temperature (T) and constant heat flux (H1 and H2). This analysis is performed for four duct geometries: elliptic, rhombic, rectangular, and regular polygons. The magnitude of this correction is greatest for the H2 wall condition and for ducts having walls with acute corners. The results of this analysis can be incorporated into a generalized correlation for the full Graetz problem in ducts of arbitrary cross section.
Quantitative Representation of Aleatoric Uncertainties in Network-Like Topological Structural Systems
Authors: Wang Zihan , Xu Hongyi 
Published: January 2021

Abstract
The complex topological characteristics of network-like structural systems, such as lattice structures, cellular metamaterials, and mass transport networks, pose a great challenge for uncertainty qualification (UQ). Various UQ approaches have been developed to quantify parametric uncertainties or high dimensional random quantities distributed in a simply connected space (e.g., line section, rectangular area, etc.), but it is still challenging to consider the topological characteristics of the spatial domain for uncertainty representation and quantification. To resolve this issue, a network distance-based Gaussian random process uncertainty representation approach is proposed. By representing the topological input space as a node-edge network, the network distance is employed to replace the Euclidean distance in characterizing the spatial correlations. Furthermore, a conditional simulation-based sampling approach is proposed for generating realizations from the uncertainty representation model. Network node values are modeled by a multivariate Gaussian distribution, and the network edge values are simulated conditionally on the node values and the known network edge values. The effectiveness of the proposed approach is demonstrated on two engineering case studies: thermal conduction analysis of 3D lattice structures with stochastic properties and characterization of the distortion patterns of additively manufactured cellular structures.
A Preliminary Investigation Into the Feasibility of Semi-Autonomous Surgical Path Planning for a Mastoidectomy Using LSTM-Recurrent Neural Networks
Authors: Korte Christopher , Schaffner Grant , McGhan Catharine L. R. 
Published: January 2021

Abstract
Path planning algorithms for robotics can be as simple as having an operator program waypoints into a robot's controller and having the robot perform a simple task such as welding. This works well in an industrial setting but will not work for complicated tasks such as performing surgery. Another approach would be to use a constraint function in programing a robot to perform surgery, but it would be difficult to capture and represent all of the surgeon's information in the mathematical terms required for a cost function. A third approach, and the one utilized in this study, is to train a set of artificial neural networks (ANNs) using recorded surgeons' motions when manipulating a surgical instrument during procedure training using a surgery simulator. This has the advantage of indirectly capturing the surgeon's abilities and intentions without needing to explicitly capture all of the motion information that must be encoded from their trajectory planning and decision-making, and then, say, creating a complex constraint function using that information. In this research effort, virtually captured surgical trajectories from trained surgeons were used to train ANNs, after being preprocessed into three subtasks. Each set of subtask data was used to train a separate ANN. Each of the ANNs was trained using a custom cost function and evaluated using custom metrics. During the training, the positions of fiducial markers, recorded during procedure attempts, were used to orient the recorded path relative to the patient's anatomy. Although the ANN-generated trajectories were not used to perform surgery on a live patient in this study, the fiducial marker position information is intended to be exploited during a real procedure to position, orient, and scale a tool trajectory to suit a patient's specific anatomy. The trained ANNs were subjected to several tests to assess their safety and robustness. We found that even when trained on a small number of datasets, the ANNs converged and could generate output trajectories that were still assessed to be safe even when slight changes in the fiducial marker placement locations were given.
Selection of an Ideal Coolant to Ward Off the Thermal Runaway of a Pouch Type Li-Ion Battery Module
Authors: Monika Kokkula , Chakraborty Chanchal , Roy Sounak , Dinda Srikanta , Singh Satyapaul A. , Datta Santanu Prasad 
Published: January 2021

Abstract
To uphold the temperature within an acceptable range of Li-ion batteries in electric vehicles, appropriate thermo-regulation strategies should be implemented. If the temperature is increased beyond the permissible range during the charging/discharging cycle, there is a possibility of overheating and electrolyte fire, which leads to degradation of the lifecycle and capability of the cell. This research suggests the usage of nanofluids as a heat transfer medium for active thermal management. A numerical approach is employed to analyze the effectiveness of nanofluids and their impact on the temperature gradient within the battery module. The thermal performance of water and water:ethylene glycol-based nanofluid is numerically examined where the water shows better performance due to excellent thermal properties, whereas the dispersion of nanoparticles in base fluids shows a notable effect on reducing the temperature of the battery module, while a limited effect on temperature uniformity. Besides, an enhancement in performance is seen with the growth in the volume fraction of nanoparticles amid an increased pumping power at the same time. The impact of different functioning parameters such as inlet velocity, coolant temperature, and discharge rate is also analyzed for water-based nanofluids. Results indicate that with an increase in coolant velocity, alumina nanofluid can provide better uniformity and reduce the battery module temperature than the base fluid.
Measurement and Prediction of Decomposed Energy Efficiencies of Lithium Ion Batteries With Two Charge Models
Authors: Huang Yuhao , Su Yan , Garg Akhil 
Published: January 2021

Abstract
A new process decomposed calculation method is developed to compare the cycle based charge, discharge, net, and overall energy efficiencies of lithium-ion batteries. Multi-cycle measurements for both constant current (CC) and constant current to constant voltage (CC-CV) charge models have been performed. Unlike most conventional efficiency calculation methods with one mean open-circuit voltage (OCV) curve, two OCV curves are calculated separately for the charge and discharge processes. These two OCV curves help to clarify the intra-cycle charge, discharge, net, and overall energy efficiencies. The relationships of efficiencies versus state of charge, state of quantity, and scaled stresses are demonstrated. Efficiency degradation patterns versus cycle numbers and scaled stresses are also illustrated with the artificial neural network (ANN) prediction method. The decaying ratios of the overall efficiencies are about 2% and 0.3% in the first 30 cycles, for CC and CC-CV, respectively. Hence, efficiencies of the CC-CV model are more stable compared with the CC model, which are shown by both experimental and ANN prediction results.
Recent Developments in Hybrid Surface Metal Matrix Composites Produced by Friction Stir Processing: A Review
Authors: Sharma Daulat Kumar , Badheka Vishvesh , Patel Vivek , Upadhyay Gautam 
Published: January 2021

AbstractThe metal matrix composites combine the metallic properties of a tough and ductile matrix with properties of reinforcement particles, simultaneously develop the functional properties by proper selection of reinforcements for projected applications. However, hard ceramics reinforcements decrease toughness and ductility of soft matrix and restrict their wide applications. The surface metal matrix composites (SMMCs) preserve the matrix properties with added advanced surface properties by reinforcing particles only in the surface layer. The hybrid surface metal matrix composites (HSMMCs) with more than one reinforcement gained attention in material processing due to their noble tribological behavior and surface properties, which cannot be attained in mono composites. Conventional liquid-phase processing techniques to fabricate hybrid surface composites result in the formation of undesirable brittle compounds, detrimental to desirable properties of composites. Friction stir processing (FSP), a solid-state processing technique, has been used by many investigators using different reinforcements to fabricate mono as well as hybrid surface composites. Friction stir processed (FSPed) hybrid surface composites have not been extensively reviewed. The current review provides a comprehensive understanding of the latest developments of FSP in hybrid surface composites manufacturing. This paper review different reinforcement strategies in the fabrication of FSPed hybrid surface composites and also the effects of single-pass, multipass, and change in pass direction on microstructure and resultant properties. Finally, future directions and challenges to FSPed hybrid surface composites are summarized. This review article containing important information on hybrid surface composites fabrication by FSP will be useful to academicians and investigators in the field.
Dimethyl Ether and Liquefied Petroleum Gas Co-Fumigation and Oxidation Catalyst Exhaust Aftertreatment: A Synergy for Improvement of Thermal Efficiency and Emissions in a Dual-Fuel Engine
Authors: Kamei Wittison , Sahoo Niranjan , Prasad V. V. D. N. 
Published: January 2021

Abstract
Gaseous hydrocarbon (HC) fuels or alcohols can partially replace diesel in compression ignition engines through the dual-fuel mode of combustion. However, such dual-fuel mode faces the challenges of high carbon monoxide (CO) and unburnt HC emissions and low thermal efficiency, particularly at low loads. The objective of this study is to achieve dual-fuel engine thermal efficiency and emissions better than those of a diesel mode while utilizing alternative fuels. A new approach consisting of a combined strategy using dimethyl ether (DME) as a co-fumigant with liquefied petroleum gas (LPG) and deployment of a customized oxidation catalyst in a single-cylinder diesel engine is presented. DME is a high-cetane oxygenate which can be produced from renewable biomass feedstock. DME and LPG are miscible, and they can be handled and stored similarly. The diesel energy replacements (36–64%) by DME and LPG are studied at low-load to part-load conditions. A customized oxidation catalyst is benchmarked with a commercial one. The dual-fuel combustion exhibits low-temperature and high-temperature reactions with significant improvement in combustion phasing. The dual-fuel mode outperforms the diesel mode and has higher thermal efficiency. The dual-fuel mode with the customized oxidation catalyst achieves emissions of CO, HC, and smoke lower than those of the diesel mode by up to 94%, 89%, and 94%, respectively. The dual-fuel engine effectively utilizes the alternative fuels and achieves drastically reduced emissions and higher thermal efficiency as compared with the diesel mode.
Adherence to recommendations for endoscopy practice during COVID-19 pandemic in Latin America: how are we doing it?
Authors: Murcio-Pérez Enrique , Zamarripa-Mottú Raúl Antonio , Andrade-DePaulo Gustavo , Aguilar-Nájera Octavio , Tchekmedyian Jorge Asadur , Blanco-Velasco Gerardo , Solórzano-Pineda Omar Michel , Hernández-Mondragón Oscar Victor , Tellez-Avila Felix 
Published: January 2021

Background and aimsDigestive endoscopy is considered a high-risk procedure for COVID-19. Recommendations have been made for its practice during the pandemic. This study was conducted to determine adherence to recommendations for endoscopy practice during the COVID-19 pandemic in Latin America (LA).MethodsA survey was conducted of endoscopists from LA consisting of 43 questions for the evaluation of four items: general and sociodemographic features, and preprocedure, intraprocedure and postprocedure aspects.ResultsA response was obtained from 338 endoscopists (response rate 34.5%) across 15 countries in LA. In preprocedure aspects (hand washing, use of face masks for patients, respiratory triage area, training for the placement/removal of personal protective equipment (PPE) and availability of specific area for the placement/removal of PPE), there was adherence in <75%. Regarding postprocedure aspects, 77% (261/338) had reused PPE, mainly the N95 respirator or higher, and this was with a standardised decontamination procedure only in 32% (108/338) of the time. Postprocedure room decontamination was carried out by 47% on >75% of occasions. In relationship to intraprocedure aspects (knowledge of risk and type of endoscopic procedures, use of PPE, airway management in patients and infrastructure), there was adherence in >75% for all the parameters and 78% of endoscopists only performed emergencies or time-sensitive procedures.ConclusionsAdherence to the recommendations for endoscopy practice during the COVID-19 pandemic is adequate in the intraprocedure aspect. However, it is deficient in the preprocedure and postprocedure aspects.
Transitioning from donor aid for health: perspectives of national stakeholders in Ghana
Authors: Mao Wenhui , McDade Kaci Kennedy , Huffstetler Hanna E , Dodoo Joseph , Abankwah Daniel Nana Yaw , Coleman Nathaniel , Riviere Judy , Zhang Jiaqi , Nonvignon Justice , Bharali Ipchita , Bandara Shashika , Ogbuoji Osondu , Yamey Gavin 
Published: January 2021

BackgroundGhana’s shift from low-income to middle-income status will make it ineligible to receive concessional aid in the future. While transition may be a reflection of positive changes in a country, such as economic development or health progress, a loss of support from donor agencies could have negative impacts on health system performance and population health. We aimed to identify key challenges and opportunities that Ghana will face in dealing with aid transition, specifically from the point of view of country-level stakeholders.MethodsWe conducted key informant interviews with 18 stakeholders from the government, civil society organisations and donor agencies in Ghana using a semistructured interview guide. We performed directed content analysis of the interview transcripts to identify key themes related to anticipated challenges and opportunities that might result from donor transitions.ResultsOverall, stakeholders identified challenges more frequently than opportunities. All stakeholders interviewed believe that Ghana will face substantial challenges due to donor transitions. Challenges include difficulty filling financial gaps left by donors, the shifting of national priorities away from the health sector, lack of human resources for health, interrupted care for beneficiaries of donor-funded health programmes, neglect of vulnerable populations and loss of the accountability mechanisms that are linked with donor financing. However, stakeholders also identified key opportunities that transitions might present, including efficiency gains, increased self-determination and self-sufficiency, enhanced capacity to leverage domestic resources and improved revenue mobilisation.ConclusionStakeholders in Ghana believe transitioning away from aid for health presents both challenges and opportunities. The challenges could be addressed by conducting a transition readiness assessment, identifying health sector priorities, developing a transition plan with a budget to continue critical health programmes and mobilising greater political commitment to health. The loss of aid could be turned into an opportunity to integrate vertical programmes into a more comprehensive health system.