bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and Control of a Robotic Steering Mechanism for Electrophysiological Catheters
Authors: Lee Hoyul , Hu Zhenkai , Moon Youngjin , Kim Young-Hak , Nam Gi-Byoung , Choi Jaesoon 
Published: August 2020

AbstractThis paper proposes a catheter robot system for cardiac ablation therapy. The robot mechanism for actuating the catheter and the control methods of the catheter tip position will be suggested. The robot system consists of a front module and a handle-control module. The front module is a dual-gripper mechanism for inserting and rotating the catheter without slip between the catheter and gripper, and the handle-control module is for controlling the knob for the bending motion of the catheter. The proposed dual-gripper mechanism has the advantage of large contact surface between the grippers and the catheter, like the human finger, allowing it to form a stable grip of the catheter. However, for continuous insertion, the grippers should be controlled interactively. To achieve this, we explain the motion-planning and trajectory-generation methods. Moreover, we propose a control method that can intuitively control the position of the catheter using a mapping system as manual work. We explain the method of updating the Jacobian model in real time using two position sensors attached to the catheter. Finally, we show the simulation and experimental results to confirm the proposed mechanism and control methods useful for controlling the catheter
A Review on the Performance, Combustion, and Emission Characteristics of Spark-Ignition Engine Fueled With 2,5-Dimethylfuran Compared to Ethanol and Gasoline
Authors: Nguyen Danh Chan , Hoang Anh Tuan , Tran Quang Vinh , Hadiyanto Hadiyanto , Wattanavichien Kanit , Pham Van Viet 
Published: August 2020

AbstractCurrently, the supply of diminishing fossil fuel reserves, and the rise in challenges in environmental, political and economic consequences have caused the great concerns in the development of modern society; these have forced the policy-makers and researchers to look for the renewable and green energy sources. Deemed as a promising renewable alternative to traditional fossil fuels, 2,5-dimethylfuran (DMF, chemical formula C6H8O)—a derivative of furan—has the potential to relieve the growing shortage of fossil fuels while satisfying the increase in global energy demand and minimizing the adverse effects of climate change. DMF can be used as a clean source of liquid transportation biofuel given the fact that it is directly obtained from biomass-derived carbohydrates. In reviewing current DMF production methods, this review paper analyzes and presents the comparison of catalytic performance in the conversion of biomass into DMF. In addition, the applicability of DMF in spark-ignition (SI) engines is thoroughly analyzed based on the spray and flame, combustion, performance, and emission characteristics of SI engines running on DMF compared with ethanol and gasoline. More interestingly, the knocking, lubrication, and wear characteristics in SI engines fueled with DMF are also evaluated and discussed. Nonetheless, further investigation on optimization strategies on DMF production process should be conducted prior to the initiation of large-scale commercialization as well as the application of DMF to real-world SI engines.
Theoretical and Experimental Studies of Internal Cuttings Removal Bit
Authors: Cao Tong , Yu Kaian , Li Wenxing , Chen Xuyue , Zhu Hongwu 
Published: August 2020

Abstract
The oil and gas exploration without rig (also known as badger exploration) is a novel exploration technology that removes the need for fixed rig drilling, bringing with it the promise of huge savings in terms of time and money and its low impact on the environment. The implementation of this technology is an autonomous exploration tool, which can drill into rock using an electrically powered bit to loosen and crush the formation ahead of it, and crushed cuttings is moved through the device and deposited in the space behind it. Because there is no drilling fluid in badger drilling, a new way of transporting cuttings is urgently needed. In this paper, a new kind of bit named internal cuttings removal (ICR) bit is developed for badger exploration, and it can not only drill rock but also collect and transport cuttings to the bit behind through the inner cavity of the bit. Compared with the common polycrystalline diamond compact (PDC) bit, the junk slots are removed, but the helical blades and screw conveyor are added on the ICR bit. Theoretically, the two effects of rotating helical blades on cuttings moving are studied, based on the conditions of low and high rotating speed, respectively. Moreover, the rate of cuttings removal of the ICR bit is given in formulas, and in order to ensure the cuttings is removed from bottomhole timely, and the maximum permissible rate of penetration (ROP) of the ICR bit is proposed. Finally, two samples of the ICR bit with different structural parameters were built and tested in dry and wet rock drilling experiments, and experimental results show that the ICR bit can achieve the expected goal of ICR, but wet cuttings has a significant influence on the performance of the ICR bit. By comparing the drilling results of two bits, it can be found that the concave blade surface, a small number of blades, and small inner cone angle have the positive effects on the cuttings removal of the ICR bit. The above work is helpful for the development and implementation of badger exploration technology.
Performance of a Natural Gas Solid Oxide Fuel Cell System With and Without Carbon Capture
Authors: Iyengar Arun K. S. , Koeppel Brian J. , Keairns Dale L. , Woods Mark C. , Hackett Gregory A. , Shultz Travis R. 
Published: August 2020

Abstract
The fuel cell program at the United States Department of Energy (DOE) National Energy Technology Laboratory (NETL) is focused on the development of low-cost, highly efficient, and reliable fossil-fuel-based solid oxide fuel cell (SOFC) power systems that can generate environmentally friendly electric power with at least 90% carbon capture. NETL’s SOFC technology development roadmap is aligned with near-term market opportunities in the distributed generation sector to validate and advance the technology while paving the way for utility-scale natural gas (NG)- and coal-derived synthesis gas-fueled applications via progressively larger system demonstrations. The present study represents a part of a series of system evaluations being carried out at NETL to aid in prioritizing technological advances along research pathways to the realization of utility-scale SOFC systems, a transformational goal of the fuel cell program. In particular, the system performance of utility-scale NG fuel cell (NGFC) systems with and without carbon dioxide (CO2) capture is presented. The NGFC system analyzed features an external auto-thermal reformer (ATR) feeding the fuel to the SOFC system consisting of planar anode-supported SOFC with separated anode and cathode off-gas streams. In systems with CO2 capture, an air separation unit (ASU) is used to provide the oxygen for the ATR and for the combustion of unutilized fuel in the SOFC anode exhaust along with a CO2 purification unit to provide a nearly pure CO2 stream suitable for transport for usage in enhanced oil recovery (EOR) operations or for storage in underground saline formations. Remaining thermal energy in the exhaust gases is recovered in a bottoming steam Rankine cycle while supplying any process heat requirements. A reduced order model (ROM) developed at the Pacific Northwest National Laboratory (PNNL) is used to predict the SOFC performance. The ROM, while being computationally effective for system studies, provides other detailed information about the state of the stack, such as the internal temperature gradient, generally not available from simple performance models often used to represent the SOFC. Such additional information can be important in system optimization studies to preclude operation under off-design conditions that can adversely impact overall system reliability. The NGFC system performance was analyzed by varying salient system parameters, including the percent of internal (to the SOFC module) NG reformation—ranging from 0 to 100%—fuel utilization, and current density. The impact of advances in underlying SOFC technology on electrical performance was also explored.
Metrics Matter: Accurately Defining Energy Efficiency in Desalination
Authors: Bouma Andrew T. , Swaminathan Jaichander , Lienhard John H. 
Published: August 2020

Abstract
Energy cost contributes a large portion of the overall cost of desalinated water. Improving the energy efficiency of desalination plants is therefore a primary design goal. However, accurately evaluating and comparing the energy consumption of desalination plants that use different forms and grades of energy is difficult, especially for power–water coproduction systems in which primary energy (PE) consumption leads to both salable electricity and potable water. The power plant converts PE into grades of thermal energy and electricity usable by the desalination plant. To fully capture the thermodynamic and economic cost of energy, and to fairly compare desalination systems that use different grades of input energy, we must compare energy consumption not at the point where energy enters the desalination plant itself, but as PE consumption entering the power plant. This paper investigates a variety of metrics for comparing the energy and exergy consumption attributable to desalination in coproduction plants. Previous results have shown that reverse osmosis (RO) is approximately twice as efficient as multiple effect distillation (MED) on a PE basis. We then compare the PE consumption of MED and RO from a thermoeconomic perspective. The entropy generation at the RO membrane and in the MED effects are derived in similar terms, which enables a comparison of the overall heat transfer coefficient in an MED system to the permeability of an RO membrane. RO outperforms MED in energy efficiency because of a balance of material costs, transport coefficients, and cost of energy.
Analytical Modeling for Vapor Condensation in the Presence of Noncondensable Gas and Experimental Validation
Authors: Zhang Wei , Wang Suilin , Lianbo Mu 
Published: August 2020

Abstract
The sensible and latent heat transfer are two essential considerations in investigating vapor condensation in the presence of noncondensable gases. In this paper, a new model for filmwise condensation heat transfer was developed using similarity-based solution. The expression of gas–liquid interfacial temperature, film thickness, and heat transfer coefficient were derived and calculated, respectively. The analytical results showed that the temperature difference between gas–liquid interfacial and cooling surface is decreased as there is an increase in cooling surface temperature. In addition, the forced-convective condensation heat transfer and film thickness on the vertical surface were experimentally carried out. The proportion of latent heat is 62–67% and relatively larger than sensible heat in the range of wall temperature (17–32.5 °C). The experimental film thickness is less than analytical film thickness by 2–10%. It is because that the liquid film may evaporate back to water vapor in the neighboring wall area due to high temperature of flue gas. Further, a new nondimensional correlation of condensation heat transfer of flue gas is fitted with Nu = 0.62Re0.5Ja0.67 and applicable range is Re = 1000–2500, Ja = 1.7–4.4. The fitting shows a good agreement between experimental and correlated values except some points in the low Nu number. The model proposed is applicable to predict the temperature and velocity distribution for condensation heat and mass transfer of multicomponent gases.
Numerical Finger Kinematic Models Derived From Virtual Grasping of Various Cylindrical Objects With the Family of Conic Sections
Authors: Won Jong-Seob , Langari Reza , Robson Nina 
Published: August 2020

Abstract
In this study, a numerical framework for joint rotation configuration models of a finger is proposed. The basic idea is to replicate the finger’s geometric posture observed when the human hand grasps a cylindrical object with various cross sections. In the model development, objects with the cross section adopted from the curves of order two (the family of conic sections) are taken into consideration to realize various finger postures. In addition, four different grasp styles, which simulate the individual-specific contact pattern between the surfaces of object and finger, are modeled and applied for the formulation of numerical models. An idea on how to change flexion/extension patterns in the middle of excursion of movement is proposed and discussed. Series of numerical studies have been conducted and analyzed to evaluate the proposed models. From the results, one can see the models’ feasibility and viability as a solution to describing finger’s flexion/extension movements (FEMs) for grasping patterns.
Influence of Working Fluid on a Novel Solar Pond Coil
Authors: Yakubu M. , Shuja S. Z. , Yilbas B. S. , Al-Qahtani M. 
Published: August 2020

Abstract
A design configuration and selection of working fluid for solar absorption remain critical for high performance of energy harvesting process in solar pond. In this study, heating and pressure loss characteristics in a novel designed spiral-coil geometry pertinent to salt-gradient solar pond (SGSP) is examined and the thermal performance of nanofluids in the coil is assessed. Nanofluids possessing graphene, functionalized graphene nanoplatelet (fGnP), and graphene oxide (GO) at 0.06% volume concentration are considered as the working fluids in the system. In order to achieve a novel design of a spiral coil, the circular cross-sectional geometries with aspect ratios (AR) of 0.5, 1, and 2 are incorporated in the analysis. The selection of the aspect ratios of 0.5, 1, and 2 results in elliptic, circular, and oval cross sections of the coil, respectively. The findings reveal that heat transfer enhances and pressure loss reduces via increasing the mass flowrate. This is due to the formation of a stable secondary flow which causes mixing enhancement while shortening the thermal entry length. Circular and elliptic cross sections resulted in the maximum and the smallest normalized average Nusselt numbers, respectively, for low rates of flow. This is because of thermal resistance created under the large surface area-to-volume ratio; however, this effect varnishes for high mass flowrates. Graphene oxide and functionalized graphene nanoplatelet have the highest and the lowest normalized average pressure drops, respectively, for all flow rates.
Data-Driven Additive Manufacturing Constraints for Topology Optimization
Authors: Weiss Benjamin M. , Hamel Joshua M. , Ganter Mark A. , Storti Duane W. 
Published: August 2020

Abstract
The topology optimization (TO) of structures to be produced using additive manufacturing (AM) is explored using a data-driven constraint function that predicts the minimum producible size of small features in different shapes and orientations. This shape- and orientation-dependent manufacturing constraint, derived from experimental data, is implemented within a TO framework using a modified version of the moving morphable components (MMC) approach. Because the analytic constraint function is fully differentiable, gradient-based optimization can be used. The MMC approach is extended in this work to include a “bootstrapping” step, which provides initial component layouts to the MMC algorithm based on intermediate solid isotropic material with penalization (SIMP) topology optimization results. This “bootstrapping” approach improves convergence compared with reference MMC implementations. Results from two compliance design optimization example problems demonstrate the successful integration of the manufacturability constraint in the MMC approach, and the optimal designs produced show minor changes in topology and shape compared to designs produced using fixed-radius filters in the traditional SIMP approach. The use of this data-driven manufacturability constraint makes it possible to take better advantage of the achievable complexity in additive manufacturing processes, while resulting in typical penalties to the design objective function of around only 2% when compared with the unconstrained case.
Studies on the Influence of Stirrer Blade Design on the Microstructure and Mechanical Properties of a Novel Aluminum Metal Matrix Composite
Authors: Krishnan Pradeep Kumar , Arunachalam Ramanathan , Husain Afzal , Al-Maharbi Majid 
Published: August 2020

AbstractIn the present work, the influence of stirrer blade design on the dispersion of reinforcement particles in the aluminum metal matrix was studied extensively through experiments and also simulated them using the computational fluid dynamics (CFD) method. The microstructure and mechanical properties of the produced metal matrix composites (MMCs) were studied. The analysis of the microstructure was performed using an optical microscope to visualize the reinforcement distribution and binding within the matrix. Further, field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD) were used to characterize the MMCs. The experimental density was assessed using the Archimedes method, and the theoretical density was determined using the mixture law to determine the percentage of porosity in the MMCs. Hardness, compression, and tensile testing were performed on the produced samples. A three-dimensional computational method was used to predict the flow field of aluminum melt and study the influence of the blade design on the distribution of the reinforcement. Experimental results validated the CFD recommendation on the blade design. The CFD recommendation was based on the structure, power number, and the number of blades, and accordingly, the four-blade flat stirrer (B4) design was the best. The experimental results also corroborated the CFD recommendation with the four-blade flat stirrer design achieving the highest compressive strength (642 MPa), highest hardness (45 HRB), and highest tensile strength (206 MPa) among the five different blade designs investigated.
Effect of Mechanical Properties on the Dynamics of Self-Oscillating Synthetic Vocal Folds
Authors: Burks Garret , Singh Manjot , De Vita Raffaella , Johnson Blake , Leonessa Alexander 
Published: August 2020

Abstract
This study focuses on the measured changes in dynamic behavior exhibited by eight synthetic vocal fold models with varying mechanical properties. Uniaxial tensile testing was conducted to determine changes in mechanical properties between materials made from silicone rubber and polydimethylsiloxane with varying mixing ratios. The results of the mechanical testing showed that the elastic modulus, E, varied from 20.6 to 437.4 kPa, the measured Poisson ratios, ν, spanned the range of 0.43–0.48, and the density, ρVF, varied from 0.86 to 1.02 g/cm3 across the eight samples. Vocal fold models were dynamically tested using a custom-built experimental setup that supplied a heated and humidified airflow to the synthetic vocal folds. The resulting sounds were recorded and analyzed to identify the change in fundamental frequency which spanned 66.8 to 342.6 Hz across the eight samples. In addition, a mathematical aeroelastic model of phonation was implemented to further investigate the relationship between the mechanical properties and phonation frequency. Finally, a proof-of-concept magnetic actuation method was demonstrated using magnetic elastomers to deform the synthetic vocal folds through the use of an electromagnet.
Injuries and illnesses among competitive Norwegian rhythmic gymnasts during preseason: a prospective cohort study of prevalence, incidence and risk factors
Authors: Gram Marte Charlotte Dobbertin , Clarsen Benjamin , Bø Kari 
Published: August 2020

ObjectivesRhythmic gymnastics is an Olympic sport that demands high training volume from early age. We investigated the extent of, and risk factors for, injuries among competitive Norwegian rhythmic gymnasts.MethodsOne hundred and seven of 133 (80.5%) female rhythmic gymnasts (mean age: 14.5 years (SD 1.6), mean body mass index: 18.9 (SD 2.2)) participated. All gymnasts completed a baseline questionnaire and the ‘Triad-Specific Self-Report Questionnaire’. Injuries, illnesses and training hours were recorded prospectively for 15 weeks during preseason using the ‘Oslo Sports Trauma Research Center Questionnaire on Health Problems’ (OSTRC-H2).ResultsResponse rate to OSTRC-H2 was 97%. Mean overuse and acute injury prevalence were 37% (95% CI: 36% to 39%) and 5% (95% CI: 4% to 6%), respectively. Incidence was 4.2 overuse injuries (95% CI: 3.6 to 4.9) and 1.0 acute injuries (95% CI: 0.5 to 1.6) per gymnast per year. Overuse injuries in knees, lower back and hip/groin represented the greatest burdens. Previous injury increased the odds of injury (OR 30.38, (95% CI: 5.04 to 183.25)), while increased age (OR 0.61 per year, (95% CI: 0.39 to 0.97)) and presence of menarche (OR: 0.20, (95% CI: 0.06 to 0.71)) reduced the odds of all injuries and substantial injuries, respectively.ConclusionsOveruse injuries were common among Norwegian rhythmic gymnasts. Younger gymnasts had higher all-injury risk. Gymnasts who were not menstruating had higher substantial injury risk. Injury prevention interventions should start at an early age and focus on preventing knee, lower back and hip/groin injuries.
Comparing negative health indicators in male and female veterans with the Canadian general population
Authors: Hall Amy L , Sweet J , Tweel M , MacLean M B 
Published: August 2020

IntroductionSex-based information on differences between Canadian veterans and the general population is important to understand veterans’ unique health needs and identify areas requiring further research. This study compared various health indicators in male and female veterans with their Canadian counterparts.MethodsHealth indicators for recent-era Regular Force veterans (released between 1998 and 2015) were obtained from the 2016 Life After Service Survey and compared with the general population in the 2015–16 Canadian Community Health Survey using a cross-sectional approach. Age-adjusted rates and 95% CIs were calculated for males and females separately.ResultsCompared with Canadians, veterans (both sexes) reported higher prevalence of fair or poor health and mental health, needing help with one or more activity of daily living, lifetime suicidal ideation and being diagnosed with mood and anxiety disorders, post-traumatic stress disorder, migraines, back problems, chronic pain, arthritis, ever having cancer, hearing problems, chronic pain and gastrointestinal problems. A higher prevalence of cardiovascular disease (all types) and high blood pressure was observed in male veterans compared with their Canadian counterparts. Within veterans only, males reported a higher prevalence of diagnosed hearing problems and cardiovascular disease compared with females; conversely females reported a higher prevalence of diagnosed migraines, mood, anxiety and gastrointestinal disorders, and needing help with activities of daily living. These sex differences are similar to the Canadian general population. Some similarities in reporting prevalence between male and female veterans (eg, fair or poor mental health, lifetime suicidal ideation, arthritis, asthma, lifetime cancer incidence, chronic pain and diabetes) were not observed in other Canadians.ConclusionMale and female veterans differed from comparable Canadians, and from each other, in various areas of health. Further research is needed to explore these findings, and veteran-based policies and services should consider sex differences.