bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Study on Mass Transfer and Electrical Performance of Anode-Supported Planar Solid Oxide Fuel Cells With Gradient Porosity Anode
Authors: Fu Pei , Yang Jian , Wang Qiuwang 
Published: October 2019

Abstract
Microstructure modification of thick anode is an effective way to enhance cell performance of the anode-supported planar solid oxide fuel cells (SOFCs). In this work, the influence of multilayer anode microstructure with gradient porosity on cell mass transfer and electrical performance is numerically investigated. The coupled phenomena of fluid flow, multicomponent mass transfer, charge transport, and electrochemical reactions of SOFC, in three-dimensions (3D), are simulated by using the finite element computational fluid dynamics approach. Quantitative analyses of hydrogen concentration and anodic overpotentials are conducted to better understand the effect mechanism of the gradient porosity anode on the cell performance. The effect of gradient porosity distribution on the cell performance is also systematically discussed. It is found that the gradient porosity anode can significantly enhance the cell mass transfer performance to reduce the anodic concentration overpotential. The combined effects of activation, concentration, and ohmic overpotentials can effectively improve the cell electrical performance. For the cases studied, porosity gradient and porosity of anode functional layer 2 (AFL2) both range from 0.1 to 0.3. Results indicate that increasing the porosity gradient or porosity of AFL2 can enhance the cell mass transfer performance. As the porosity of AFL2 is higher than 0.2, the gradient porosity anode design is beneficial to improve the cell electrical performance.
Nonlinear Electro-Thermal Monte Carlo Device Simulation
Authors: Merrill Ky , Saraniti Marco 
Published: October 2019

Abstract
A model of self-heating is incorporated into a cellular Monte Carlo (CMC) particle device simulator. This is done through the solution of an energy balance equation (EBE) for phonons, which self-consistently couples charge and heat transport in the simulation. First, several tests are performed to verify the applicability and accuracy of the proposed nonlinear iterative solver in the presence of convective boundary conditions, as compared to a finite element analysis (FEA) solver as well as using the Kirchhoff Transformation. Finally, a fully coupled electro-thermal characterization of a GaN/AlGaN high electron mobility transistor (HEMT) is performed, and the effects of nonideal interfaces and boundary conditions are studied.
Reconsidered Method for Validation of Experimental Data for Direct Contact Condensers With Zero Vapor Outflow
Authors: Jaćimović Nikola 
Published: October 2019

Abstract
Method presented in the paper is a reconsideration of the already published equations for a quick and reliable verification of experimental results related to direct contact condensers with zero vapor outflow. Both original and reconsidered methods presented by the author are confirmed by a large number of experimental data (more than 1250 total data points) which took over one decade of experiments on four different column types. Both methods draw the background in sound and simple theory and should be considered as very reliable while easy to use in practice.
Perforated Rib in Turbulent Boundary Layer
Authors: Afanasiev Valery N. , Kong Dehai , Isaev S. A. 
Published: October 2019

Abstract
This study presents the results of the experimental study on hydrodynamics and heat transfer in separation zone in front and behind a single rectangular perforated rib mounted on a flat plate. The effects of perforation open-area ratio (β = 12%, 23.5%, and 44%) and the location of the hole on the rib (at the bottom, at the top, and in a staggered arrangement) on the mean and fluctuating characteristics of the turbulent dynamic and thermal boundary layers in the median section of the plate were examined. It was established that the stagnant and recirculation zones in the front and behind the perforated rib were shifted and became smaller or disappeared.
Experimental Study of Spark Plasma Stretching and Combustion Variations Analysis Using Flame Luminosity Images From an Optically Accessible Internal Combustion Engine
Authors: Afkhami Behdad , Wang Yanyu , Miers Scott A. , Naber Jeffrey D. 
Published: October 2019

Abstract
Understanding the behavior of spark plasma and flame initiation in internal combustion engines leads to improvement in fuel economy and exhaust emissions. This paper experimentally investigated spark plasma stretching and cycle-to-cycle variations under various engine speed, load, and air–fuel mixtures using natural luminosity images. Natural luminosity images of combustion in an IC engine provide information about the flame speed, rate of energy release, and combustion stability. Binarization of the intensity images has been a desirable method for detecting flame front and studying flame propagation in combustors. However, binarization can cause a loss of information in the images. To study spark plasma stretching, the location of maximum intensity was tracked and compared to the trajectory of the flame centroid in binarized images as a representative for bulk flow motion. Analysis showed comparable trends between the trajectories of the flame centroid and spark stretching. From three air–fuel mixtures, the spark plasma for the lean mixture appeared to be more sensitive to the stretching. In addition, this research investigated combustion variations using two-dimensional (2D) intensity images and compared the results to coefficient of variation (COV) of indicated mean effective pressure (IMEP) computed from in-cylinder pressure data. The results revealed a good correlation between the variations of the luminosity field during the main phase of combustion and the COV of IMEP. However, during the ignition and very early flame kernel formation, utilizing the luminosity field was more powerful than in-cylinder pressure-related parameters to capture combustion variations.
Toward a Better Understanding of Crack Growth in Nickel-Cast Alloys Under Creep-Fatigue and Thermo-Mechanical Fatigue Conditions
Authors: Kraemer Karl Michael , Mueller Falk , Kontermann Christian , Oechsner Matthias 
Published: October 2019

Abstract
To ensure the feasibility of gas turbines, despite rising commodity prices and emission restrictions, an enhancement of both their efficiency and flexibility is necessary. The consequential higher loading of components at high temperature conditions calls for an increased use of damage tolerant design approaches. To still guarantee a safe operation, a sound understanding and reliable estimations for crack growth under service conditions are indispensable. In this paper, the results from several projects in this field conducted at the TU Darmstadt and involved partners are summarized to identify and describe the various influences on crack growth under creep-fatigue and thermo-mechanical fatigue (TMF) loading. The activation of damage mechanisms under TMF loading and interactions between them is dependent on the temperature cycle and the respective load phasing. Depending on the type of loading (force versus strain control), contrary influences of the phase shift on the TMF crack growth rates are found. This can partially be attributed to the differences in mean stress evolution. Crack initiation and propagation under creep-fatigue and TMF conditions are also often connected with significant scattering of initiation sites and crack growth rates. One reason for this nonuniform behavior is the interaction of geometric discontinuities with the microstructure. To investigate the role of the local grain structure for crack initiation and propagation, in situ observation techniques for crack tip movement and local strain fields were applied. Harsh gradients in the local deformation behavior were identified as origins of secondary crack initiation. To describe crack growth under creep-fatigue and TMF conditions, the linear accumulation model “O.C.F.” was developed. It is based on the contributions of fatigue, creep, and oxidation to crack growth per load cycle. This model is capable of reproducing the effects of time-dependent damage, different load ratios, TMF phase shifts, as well as component geometry. Substantial advantages of this method are its independence from empiric correction factors to assess changing load cycle forms and the possibility to give analytic estimations without the need of extensive data processing. The model is currently validated for three nickel cast alloys, also including single-crystalline and directionally solidified cast variants, different creep-fatigue and TMF loading scenarios, and crack geometries. The model's linear formulation allows assessing the dominant driver of crack growth at each stage of an experiment. These predictions are compared with fractographic investigations and in situ observations of crack paths to identify the mechanisms of crack growth under different TMF load cycle forms.
A Base Study to Investigate MASH Conservativeness of Occupant Risk Evaluation
Authors: Schulz Nathan , Dobrovolny Chiara Silvestri , Hurlebaus Stefan , Prodduturu Harika Reddy , Arrington Dusty R. , Rupp Jonathan D. 
Published: October 2019

Abstract
The manual for assessing safety hardware (MASH) defines crash tests to assess the impact performance of highway safety features in frontal and oblique impact events. Within MASH, the risk of injury to the occupant is assessed based on a “flail-space” model that estimates the average deceleration that an unrestrained occupant would experience when contacting the vehicle interior in a MASH crash test and uses the parameter as a surrogate for injury risk. MASH occupant risk criteria, however, are considered conservative in their nature, due to the fact that they are based on unrestrained occupant accelerations. Therefore, there is potential for increasing the maximum limits dictated in MASH for occupant risk evaluation. A frontal full-scale vehicle impact was performed with inclusion of an instrumented anthropomorphic test device (ATD). The scope of this study was to investigate the performance of the flail space model (FSM) in a full-scale crash test compared to the instrumented ATD recorded forces which can more accurately predict the occupant response during a collision event. Additionally, a finite element (FE) model was developed and calibrated against the full-scale crash test. The calibrated model can be used to perform parametric simulations with different testing conditions. Results obtained through this research will be considered for better correlation between vehicle accelerations and occupant injury. This becomes extremely important for designing and evaluating barrier systems that must fit within geometrical site constraints, which do not provide adequate length to redirect test vehicles according to MASH conservative evaluation criteria.
Torque Distribution Strategy for Multi-PMSM Applications and Optimal Acceleration Control for Four-Wheel-Drive Electric Vehicles
Authors: Song Ziyou , Hofmann Heath , Li Jianqiu , Wang Yuanying , Lu Dongbin , Ouyang Minggao , Du Jiuyu 
Published: October 2019

Abstract
In this paper, a general torque distribution strategy is proposed to improve the drivetrain efficiency of four-wheel-drive electric vehicles (EVs). The strategy allows the same or different motors to be equipped in the front and rear wheels. The model of the drivetrain considers the loss properties of four permanent magnet synchronous motors (PMSMs) and four inverters over a wide range of torque and speed. The relationship between the drivetrain efficiency and the torque split ratio at any given speed is proven to be convex under both traction and regenerative braking conditions. It is shown that, when all four motors are identical, the maximum efficiency can be achieved if the total torque is equally shared. An equivalent loss strategy, which is a general method and can solve many optimization problems of multi-PMSM applications, is proposed to maximize the drivetrain efficiency when different PMSMs are used in the front and rear wheels. The effectiveness of the proposed strategy is verified using an urban dynamometer driving schedule (UDDS). In addition, the acceleration process of EVs is optimized using a dynamic programming approach to minimize acceleration duration and energy consumption. Simulation results show that, with the proposed strategy, the energy loss during the acceleration can be reduced by up to 15%.
Laminar Flame Speed Experiments of Alternative Liquid Fuels
Authors: Keesee Charles L. , Guo Bing , Petersen Eric L. 
Published: October 2019

Abstract
New laminar flame speed experiments have been collected for two alternative liquid fuels. Understanding the combustion characteristics of these synthetic fuels is an important step in developing new chemical kinetics mechanisms that can be applied to real fuels. Included in this study are two synthetic Jet fuels: Syntroleum S-8 and Shell GTL. The precise composition of these fuels is known to change from sample to sample. Since these are low-vapor pressure fuels, there are additional uncertainties in their introduction into gas-phase mixtures, leading to uncertainty in the mixture equivalence ratio. An in-situ laser absorption technique was implemented to verify the procedure for filling the vessel and to minimize and quantify the uncertainty in the experimental equivalence ratio. The diagnostic utilized a 3.39-μm HeNe laser in conjunction with Beer's law. The resulting spherically expanding, laminar flame experiments were conducted over a range of equivalence ratios from φ = 0.7 to φ = 1.5 at initial conditions of 1 atm and 403 K in the high-temperature, high-pressure (HTHP) constant-volume vessel at Texas A&M University. The experimental results show that both fuels have similar flame speeds with a peak value just under 60 cm/s. However, it is shown that when comparing the results from different datasets for these real fuels, equivalence ratio may not be the best parameter to use. Fuel mole fraction may be a better parameter to use as it is independent of the average fuel molecule or fuel surrogate used to calculate equivalence ratio in these real fuel/air mixtures.
Genetic characterisation of 22q11.2 variations and prevalence in patients with congenital heart disease
Authors: Hou Hai-Tao , Chen Huan-Xin , Wang Xiu-Li , Yuan Chao , Yang Qin , Liu Zhi-Gang , He Guo-Wei 
Published: October 2019

ObjectivesThe 22q11.2 deletion syndrome is considered the most frequent chromosomal microdeletion syndrome in humans and the second leading chromosomal cause of congenital heart disease (CHD). We aimed to identify the prevalence and the detailed genetic characterisation of 22q11.2 region in children with CHD including simple defects and to explore the genotype-phenotype relationship between deletion/amplification type and clinical data.MethodsPatients with CHD for surgery were screened by multiplex ligation-dependent probe amplification and capillary electrophoresis methods. Universal Probe Library technology was applied for validation.ResultsIn 354 patients with CHD, 40 (11.3%) carried different levels of deletions/amplifications at the 22q11.2 region with various phenotypes. The affected genes at this region includeCDC45(15 patients),TBX1(8),USP18(8),RTDR1(7),SNAP29(6),TOP3B(6),ZNF74(4) and other genes with less frequency. Among those, two patients carried 3 Mb typically deleted region fromCLTCL1toLZTR1(low copy repeats A–D) or 1.5 Mb deletions fromCLTCL1toMED15(low copy repeats A–C). Clinical facial manifestations were found in 12 patients.ConclusionsThis study revealed an unexpected high prevalence of chromosome 22q11.2 variations in patients with CHD even in simple defects. The genotype-phenotype relationship analysis suggests that genetic detection of 22q11.2 may become necessary in all patients with CHD and that detection of unique deletions or amplifications may provide useful insight into personalised management in patients with CHD.
Potentially preventable hospitalisations in children: a comparison of definitions
Authors: Procter Alexandra M , Pilkington Rhiannon M , Lynch John W , Smithers Lisa G , Chittleborough Catherine R 
Published: October 2019

ObjectiveTo compare admission rate, cumulative incidence and social distribution of potentially preventable hospitalisations (PPHs) among children according to the current Australian adult definition, and the child definition developed in New Zealand.Design, setting, participantsDeidentified, linked public hospital, births registry and perinatal data of children aged 0–10 years born 2002–2012 in South Australia (n=1 91 742).Main outcome measuresPPH admission rates among 0–10 year olds and cumulative incidence by age 5 under the adult and child definitions. Cumulative incidence was assessed across indicators of social and health disadvantage.ResultsPPH admission rates among 0–10 year olds were 25.6 (95% CI 25.3 to 25.9) and 59.9 (95% CI 59.5 to 60.4) per 1000 person-years for the adult and child definitions, respectively. Greater absolute differences in admission rates between definitions were observed at younger ages (age <1 difference: 75.6 per 1000 person-years; age 10 difference: 1.4 per 1000 person-years). Cumulative incidence of PPHs among 0–5 year olds was higher under the child (25.0%, 95% CI 24.7 to 25.2) than the adult definition (12.8%, 95% CI 12.6 to 13.0). Higher PPH incidence was associated with social and health disadvantage. Approximately 80% of the difference in admission rate between definitions was due to five conditions.ConclusionsRespiratory conditions and gastroenteritis were key contributors to the higher PPH admission rate and cumulative incidence among children when calculated under the child definition compared to the adult definition. Irrespective of definition, higher PPH cumulative incidence was associated with social and health disadvantage at birth.
Fabry keratopathy: manifestations and changes over time
Authors: Sivley Melanie D , Benjamin William J 
Published: October 2019

AimsThe goal was to find if changes in Fabry keratopathy were clinically observable over time. Also observed were variations of Fabry keratopathy, supplemental features, unique presentations and differences between keratopathies of right and left corneas and the same family and genotype.MethodsBiomicroscopic images of Fabry keratopathy in 10 persons with classic Fabry disease, 5 men and 5 women, were captured over an 18-month period. The keratopathies were categorised and scrutinised for changes over time, and differences between corneas of the same individual, family and genotype.ResultsFabry keratopathy ranged from mild change to marked change over 18 months. There was a great variety of whorl patterns. A few keratopathies were amorphous without vortices and many vortices were supplemented with amorphous features. All keratopathies were accompanied by diffuse epithelial haze. There was a range from negligible difference to marked difference between right and left eyes of the same individuals with similarities appearing as imprecise mirror images of each other. In some corneas, prominent vertical streams from the superior limbus integrated into the primary keratopathy. Comparisons between persons with the same family and genotype were obscured by gender and differences between right and left eyes.ConclusionsPractitioners should be better able to detect Fabry disease having a fuller understanding of the variety of presentations of the dynamic, pathognomonic Fabry keratopathy. Routes of continuous centripetal renewal of corneal epithelium are spatially unique to each eye, in some cases subsidised by direct contribution of basal cells streamed from the superior limbus.
Anterior quadratus lumborum block analgesia for total hip arthroplasty: a randomized, controlled study
Authors: Kukreja Promil , MacBeth Lisa , Sturdivant Adam , Morgan Charity J , Ghanem Elie , Kalagara Hari , Chan Vincent W S 
Published: October 2019

Background and objectives
Quadratus lumborum (QL) block is a new regional analgesic technique for upper and lower abdominal surgeries as part of a multimodal analgesic regime. It has also been reported to relieve pain after total hip arthroplasty (THA). In this prospective, randomized, double-blind study, we compared QL block with control (no block) in patients undergoing primary THA.

Methods
Eighty patients undergoing primary THA surgery under spinal anesthesia were randomized into two groups, one with and one without QL block. The patients in both groups were randomized after sedation, positioning and ultrasound scanning. Both the patient and the researcher collecting data were blinded to the patient’s group assignment. Opioid consumption and visual analog scores (VAS) pain scores were measured at 12, 24, and 48 hours after surgery. Also, the ambulation distance, patient satisfaction, and length of stay were recorded.

Results
The study analysis included 36 patients in the QL group and 35 patients in the control group. Both VAS pain score at 24 hours (difference −1.76, 95% CI −2.87 to −0.64) and cumulative opioid consumption were significantly lower in the QL group at 12, 12–24, 24, 24–48, and 48 hours after surgery as compared with the control group (difference at 48 hours −36.13, 95% CI −62.89 to −9.37) (p<0.05). However, there was no difference in pain score at 12 and 48 hours, nor in the ambulation distance and duration of hospital stay between the two groups. The patient satisfaction score was significantly higher in the QL group.

Conclusions
Our preliminary data show that the QL block provided effective analgesia and decreased opioid requirements up to 48 hours after primary THA.

Trial registration number

NCT03408483
Lung function and asthma control in school-age children managed in UK primary care: a cohort study
Authors: Lo David KH , Beardsmore Caroline S , Roland Damian , Richardson Mathew , Yang Yaling , Danvers Lesley , Wilson Andrew , Gaillard Erol A 
Published: October 2019

BackgroundSpirometry and fraction of exhaled nitric oxide (FeNO) are commonly used in specialist centres to monitor children with asthma. The National Institute for Health and Care Excellence recommends spirometry for asthma monitoring from 5 years in all healthcare settings. There is little spirometry and FeNO data in children managed for asthma in UK primary care to support their use.ObjectivesTo study the prevalence of abnormal spirometry and FeNO in children with asthma managed in primary care and to explore their relationship with asthma control and unplanned healthcare attendances (UHA).MethodsProspective observational cohort study in children aged 5–16 years with suspected or doctor-diagnosed asthma attending an asthma review in UK general practice. Spirometry, FeNO, asthma control test (ACT) scores and number of UHAs were studied.ResultsOf 612 children from 10 general practices, 23.5% had abnormal spirometry, 36.0% had raised FeNO ≥35 parts per billion and 41.8% reported poor control. Fifty-four per cent of children reporting good asthma control had abnormal spirometry and/or raised FeNO. At follow-up, the mean number of UHAs fell from 0.31/child in the 6 months preceding review to 0.20/child over the 6 months following review (p=0.0004). Median ACT scores improved from 20 to 22 (p=0.032), and children’s ACT from 21 to 23 (p<0.0001).ConclusionsAbnormal lung function and FeNO are common in children attending for asthma review in primary care and relate poorly to symptom scores. A symptoms-based approach to asthma monitoring without objective testing is likely to miss children at high risk of future severe asthma attacks.