bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution of Turbine Rear Frame Design for Aero Derivative Engine
Authors: Katti Srinidhi , Reddy Vishnu Vardhan , Chippa Anil Kumar , Babu S. , Casadio Federico
Published: October 2022

As the world’s demand for energy continues to grow, gas turbines are looked at as one of main options for power generation. Among the aero derivative and heavy-duty designs, designers are leaning towards aero derivative architecture due to advantage it offers in terms of performance, footprint, and weight. Gas turbine engineers identify “exhaust casing” as the casing which forms the hot gas path after the last stage of the turbine, to recover back pressure and thereby contributing the increased performance of the turbine. In the same way, in aero derivative engines this casing is called as “Turbine Rear Frame (TRF)”. By virtue of aero derivative design philosophy, TRF is exposed to hot gases on one side and colder ventilation air on other side, posing a challenge to designer in terms of thermo-mechanical design aspects. TRF also functions as a load bearing member by transferring loads from all other casings to foundation, using its support legs. The hollow struts of TRF forms a passage for all bearing piping and few secondary flows. All these piping and colder secondary flows have influence on the design of TRF. This paper presents a comparative study of how various configurations of TRF evolved under Baker Hughes Aero derivative portfolio, which concentrates on secondary flow circuit and thermal design aspects, and its impact on component design. This also covers improved aspects in thermal modeling to match the test data measurements. The impact of different thermal behavior on the component with respect to stress, deformation and stiffness are studied. It also captures the effect of secondary flow circuit modifications on the component interfaces. The aspect of design iterations considering the Ultimate load comparing various versions will also be highlighted.
Numerical Study of Three Gaseous Fuels on the Reactor Length and Pollutant Formation Under Lean Gas Turbine Conditions
Authors: Stiehl Bernhard , Otto Marcel , Newmyer Malcolm , Fortin Max , Genova Tommy , Ahmed Kareem , Kapat Jayanta , Orsino Stefano , Arguinzoni Carlo
Published: October 2022

The present paper numerically studies the impact of three gaseous fuels on the reaction characteristics and pollutant formation in a lean combustion system. The models include an equilibrium calculation with Ansys-Chemkin-Pro, as well as a 3D half-width CFD model using Large Eddy Simulation (LES) and Adaptive Mesh Refinement (AMR) models. The outcomes are targeted to benefit the transition to carbon-free operation of aviation turbines. Three fuels, methane (CH4), hydrogen (H2), and ammonia (NH3) as well as blends thereof were compared at constant equivalence ratios to obtain a firing temperature level of T = 1800°C. The kinetic mechanism in use was suggested and validated by Okafor et al., including 42 species to describe CH4/H2/NH3-air combustion and NOx chemistry. The formation of nitrogen oxide pollutants (NO, NO2 and N2O) were analyzed to determine the sensitivity to the three fuels and their blends. Secondly, a fuel injector scaling study was performed, and a significantly larger jet diameter was selected to compensate for the increased stoichiometric mixture fraction and reduced blend density relative to CH4-fueled architecture. Lastly, the three-dimensional AMR-LES model provided validation of the injector re-sizing, as well as further insight into the expected fuel-air distribution by convective mixing. While the substitution of methane-fueled gas turbines with carbon-free alternatives is generally feasible, blending of H2 and NH3 fuels could be a promising strategy to utilize existing turbine combustors, while retaining reaction timescales close to those of CH4-powered systems.
The Effect of Circumferential Lengthscale on Hot Gas Ingestion
Authors: Dawson Michael G. , Otter John J. , Atkins Nicholas R.
Published: October 2022

This paper demonstrates that long wavelength circumferential pressure variations, an order of magnitude smaller than those created by vanes and blades, are a mechanism of hot gas ingestion. Using experimental, analytical, and numerical methods, it is shown that ingestion depends on both the amplitude and wavelength of a pressure variation, and is driven by the superposition of variations with different wavelengths. A model is presented which demonstrates the sensitivity of hot gas ingestion due to these variations. The model uses the linearised Euler equations to calculate the seal velocity field, and track the movement of mainstream gas into the rotor-stator cavity. Following this understanding, full annulus numerical simulations show that the introduction of long wavelength boundary conditions allow accurate prediction of hot gas ingestion for the double-lip seal tested, using unsteady RANS simulations.
IDAES Platform for Evaluating Thermal Energy Storage for Coal-Fired Indirect sCO2 Power Cycles
Authors: Schmitt Joshua , Karg Bulnes Fernando , Mathur Anoop
Published: October 2022

This paper demonstrates the modelling of a novel power cycle for coal-fired indirect supercritical carbon dioxide (sCO2). and thermal energy storage (TES). TES integrated with coal fired power plant can improve the efficiency, making the power generator responsive to ramp rate. The parallel models were developed in IDAES, an open-source code developed by the Department of Energy (DOE), and Aspen Plus V.10 by Aspen Technology, Inc., which is used in many industries to model and optimize a variety of chemical processes. The benefit of using Aspen Plus for coal combustion is its ability to model solids and multiphase fluids that will be present in the various coal and sCO2 power cycles. The property database and equations of state (EOS) available in the Aspen and IDAES software provide accurate results for the process conditions present in the cycles involved in this project.

A baseline model was selected from DOE studies and compared against results from the system modelling. Current results from the model are close to those found using Aspen and those in the baseline model. The system model was also connected to a dual-media thermocline thermal energy storage system (DMTES) that uses a Python script to determine temperatures of molten salt provided by the DMTES. The code uses variables of heat flow, mass flow, and temperature to determine the performance of the sCO2 power block IDAES model. From this, the power block output is determined for steady state and quasi steady state conditions. The DMTES system is modeled for dynamic situations and is shown to have near-constant temperature during charge or discharge, depending on the position of the DMTES system thermal transition zone. The results show how temperature is maintained across a large range of state-of-charge.
Gradient Enhanced Kriging Using Modal Sensitivity Approximations in a Reduced Basis Space for As-Manufactured Airfoil Analysis
Authors: Brown Jeffrey M. , Carper Emily B. , Kaszynski Alex A. , Gillaugh Daniel L. , Beck Joseph A.
Published: October 2022

This work develops a new process to efficiently predict the effect of as-manufactured geometry variations on airfoil modal response. A gradient enhanced kriging approach is formulated that uses two sets of results at the training model sites in order to reduce the total number of models required. The first set of results are the frequency or mode shape values and the second are their respective gradients. Computational efficiency is achieved through analytical calculations of eigenvalue and eigenvector sensitivities. This approach avoids the need to recompute full eigensolutions for finite difference sensitivity approximation. Efficiency in mode shape approximation is further enabled through transformation of displacement variations into a principal component reduced-basis space. This allows prediction of the full mode shape variation without emulating each degree of freedom independently. In order to perform gradient enhanced kriging with this space, a novel approach is developed to calculate reduced basis space gradients. The process projects the modal displacement principal component vectors onto first-order Taylor series expansions of the physical mode shape variation at each training site. The resulting perturbed principal component coordinates are used in finite difference estimates of sensitivity that make gradient enhanced kriging in this space possible. This new process is demonstrated on three cases, and it is shown that the new approach provides significant improvements in accuracy and efficiency compared to traditional kriging methods.
Experimental and Numerical Investigation of Effect of Inclination on sCO2 Heat Transfer in a Circular Pipe
Authors: Gabriel-Ohanu Emmanuel , Shah Alok , Khadse Akshay , Fernandez Erik , Kapat Jayanta S.
Published: October 2022

Supercritical carbon dioxide (sCO2) can be utilized as a working fluid in various thermal systems including large scale power cycles; portable power production units, centralized coolant systems and standalone cooling devices. However,the lack of accurate prediction tools such as heat transfer coefficient correlations, and insufficient research studies about the mechanisms controlling heat transfer processes, are hindering its practical realization for key energy and cooling systems. The overall objective of this study is to extend fundamental knowledge about heat transfer and fluid dynamic processes in conduits pertinent to sCO2 with an emphasis on flow inclination and directional effects. This paper present the a study on effects of gravity, buoyancy on sCO2 flow at temperature near and away from the pseudocritical temperature. The experimental setup consists of a high temperature and pressure sCO2 heat transfer loop and flow testing facility. Recently researched sCO2 heat exchangers can have tubes oriented at different angles such as 45° or 90° to horizontal. For optimized design of efficient and cost-effective turbo-machinery components utilizing sCO2 as the heat transfer fluid, an understanding of convective heat transfer inside a tube/pipe is equally as important as external heat transfer. This paper presents an experimental and numerical study on sCO2 heat transfer at various inclinations with angles ranging from 0° (horizontal) to 90° (vertical) along with upward and downward flow direction with different inlet temperature. Thermocouple based temperature measurement is utilized at multiple locations within the test section axially and circumferentially to study the temperature distributions on the tube surface. Computational Fluid dynamics (CFD) simulations have been performed using ANSYS Fluent to complement experimental data. The CFD and experiment have been analysed against known Gnielinski nusselt number correlation.
Accurate Blade Tip Timing Placement on a Centrifugal Impeller Using As-Manufactured Modeling
Authors: Gillaugh Daniel L. , Kaszynksi Alexander A. , Tomlin Trevor C. , Brown Jeffrey M. , Beck Joseph A. , Carper Emily B.
Published: October 2022

Non-intrusive stress measurement systems (NSMS) are commonly used during rig and engine tests to ensure safe operation of the test asset. Blade tip timing (BTT) is one form of NSMS that estimates operational stresses of a bladed rotor using time-of-arrival (TOA) data coupled with finite element analysis (FEA) predictions. Traditional FEA techniques assume nominal airfoils to generate stress-to-deflections ratios used with TOA data to predict blade stresses. Recent research has been conducted showing the significant variability in stress-to-deflection ratios when accounting for geometric variations in the blade geometry. As-manufactured finite element modeling has been shown to be a prudent way to account for these geometric variations when developing instrumentation placements and safety limits for rotors. Literature on this topic tends to focus on integrally bladed rotors where every blade is notionally identical. Centrifugal impellers alternatively have a main and splitter blade with significantly different geometries making blade tip timing placement more challenging on these components. Traditional BTT placement techniques will be tailored in this work to achieve optimal probe placement to detect specific vibratory modes of interest for both the main and splitter blades. BTT safety limits will be generated for each mode of interest, and optical scanning and mesh morphing approaches will be used to generate an as-manufactured model of the centrifugal impeller. The BTT safety limit variability due to geometric variations will be assessed for both the main and splitter blades. It will be shown that due to geometric variations within the impeller that the BTT limits can vary between blades. This research further validates the importance of using as-manufactured modeling during component design, test, and throughout the life-cycle.
Experimental Investigation of Inlet Stagnation Pressure Distortion Effects on a Transonic Axial Compressor Rotor
Authors: Oliva Andrew A. , Morris Scott C.
Published: October 2022

This work shows the results of an experimental investigation of a transonic axial compressor subjected to a 120° circumferential inlet distortion. The goal of the investigation was to determine the rotor performance when exposed to a circum-ferentially non-uniform inlet stagnation pressure. The upstream grid was rotated with respect to the fixed instrumentation to provide high resolution information around the annulus. The resulting rotor performance characteristics are shown for 70% and 100% corrected speeds. The results showed that the distorted and undistorted rotor performance differed significantly from the uniform inlet rotor performance. The undistorted compressor performance saw higher maximum inlet Mach numbers than the corresponding uniform characteristic. The distorted compressor performance had stable operating conditions at lower inlet Mach numbers and higher stagnation pressure ratios than the uniform characteristic. The rotor performance orbits were hypothesized to be related to the pre-swirl and counter-swirl created by the inlet circumferential static pressure gradient.
Numerical Investigation on Mitigation of Heat Transfer Deterioration of Supercritical CO2 Flow by Introducing Multiple Turbulators Along Helices in a Circular Tube
Authors: Duan Hangfei , Xie Gongnan , Ma Yuan , Li Shulei
Published: October 2022

In order to effectively alleviate the heat transfer deterioration phenomenon of supercritical CO2 (S-CO2) in a vertical circular tube, explores the fluid hydraulic and thermal performance of multiple turbulator distributed along helices through a verified standard k-ω model. The effects of the pitch and the height of turbulators on flow characteristic and heat transfer are observed and analyzed in detail. With the increase of the height of turbulators, the heat transfer coefficient increases significantly. Besides, as the pitch decreases, the fluid re-circulation area behind each turbulator decreases, resulting in stronger mixing of swirling flow, which enhances turbulent kinetic energy of downstream fluid and weakens buoyancy force, thus mitigating heat transfer deterioration. The present results suggest that introducing multiple turbulators distributed along helices into circular tube can be a beneficial way to alleviate heat transfer deterioration and to enhance heat transfer of supercritical CO2 flow.
A Numerical Investigation of Sweeping Air/Mist Jet Film Cooling Through a Passive Fluidic Oscillator, Part II: Sweeping Air/Mist Jets
Authors: Abdelmaksoud Ramy , Wang Ting
Published: October 2022

An ongoing research effort has been conducted for years to investigate the feasibility of mixing the air with mist (micron-level water droplets) to enhance heat transfer. It becomes very interesting to investigate how these tiny droplets behave in conjunction with the periodic sweeping jets. Will they move synchronously with the fluid or asynchronously with a phase lag? How would the interaction between the droplets and the sweeping jets affect the film cooling effectiveness? To answer these questions, Part II of this paper specifically focuses on investigating the droplet dynamics and thermo-flow behavior of droplet evaporation on film cooling effectiveness in a sweeping jet. An unsteady Reynolds Averaged Navier-Stokes (URANS) simulation accompanied by the k-ω SST turbulence model is used in this study. The multiphase CFD model employs an Eulerian-Lagrangian approach. The Eulerian method is used for the continuous phase including air and water vapor and the Lagrangian method in terms of the discrete phase model (DPM) is used to simulate the dispersed phase (e.g., liquid droplets) in a continuous phase (e.g., air). A mist ratio of 10% with a droplet size of 10 microns were used in this study. The results show that, for a blowing ratio of 1, using mist provides better film cooling performance with an average enhancement of 50–90% in comparison to that without mist. Using a mist ratio of 10% could save approximately 50% of the cooling air. It is observed that the liquid droplets mostly follow the main sweeping flow and its vortical structure and horseshoe vortices, but with a phase lag between the droplets and the main sweeping jet. This phase lag further enhances both temporal and spatial film cooling surface protection during the sweeping motion.
Numerical Investigation on HCF Weak Link Locations of a Wide-Chord Laminated Composite Fan Blade With Coupled Modal Vibrations
Authors: Tang Xu , Chen Yong , Zhang Jiguo
Published: October 2022

High cycle fatigue (HCF) of laminated composite fan blade (LCFB) caused by vibration is important content within airworthiness certification. This paper proposed a method suitable for LCFB to evaluate its HCF failure location under complex excitations. First, a high-fidelity finite element model (FEM) of LCFB was built and the classification of modal shapes was carried out. By setting the resonance margin threshold on the campbell diagram, the modal superposition vibration that may be excited at the common rotation speed was found out. Then, a postprocessing strategy was proposed to evaluate HCF weak link locations. Constant life diagrams (CLD) for the unidirectional lamina were employed to determine the HCF weak link location of LCFB in combination with the steady and vibratory stresses along the corresponding material principal directions. For the coupled mode vibration, the HCF weak link locations with different stress components were calculated and the critical failure stress component was identified. For the coupled mode vibrations, the HCF weak link locations with the resultant stresses were calculated with different combination of modal participating coefficients. The results indicated that the HCF weak link locations may change to locations different from that in single mode vibration. Furthermore, the critical failure stress components may be transferred to directions with larger vibratory stress margins. This work presented a useful numerical technique to study the effect of mode coupling on LCFB HCF characteristics under complex operating conditions.
Impact of High Hydrogen Operation on Combustor Performance
Authors: Mohammad Bassam S. , Magina Nicholas , Volk Brian , Mcmanus Keith
Published: October 2022

As the interest in high hydrogen operation is gaining momentum, this paper quantifies the impacts associated with switching from natural gas to 100% hydrogen, leveraging both modelling techniques and experimental data. From the modeling standpoint, a perfectly stirred reactor network model was setup in Cantera. Flame speed increases of up to 50 times that of natural gas were observed with increasing hydrogen content, indicating a significant increase in flashback propensity. This suggests that DLE combustion systems might offer an advantage over RQL systems, operating at low equivalence ratios where the flame speed impact is milder. Additionally, the model shows that the blow off time can be used to classify hydrogen operation into three regimes. With increasing hydrogen content, the BOT begins similar to that of propane and declines at different rates in each regime, establishing the added operational challenges associated with high hydrogen content operation. Equivalence ratio dependencies were investigated along with NOx penalties, where a predicted penalty of ∼40–65% was observed within the flame temperature range of 1750–1950K. Experimentally, a new advanced mixer was used, enabling operation of the full spectrum of natural gas and hydrogen blends up to 100% hydrogen. The impact of hydrogen content on NOx emissions for a representative operating condition was investigated. Comparisons with the model predictions were made, revealing discrepancies, which were investigated and justified thru a mixedness and residence time framework. Finally, the authors show that the proper way to regulate future combustors running with 100% hydrogen should be based on NOx and not NOx15. The findings reported here help clarify and shape the future hydrogen enabling technologies, reaffirming the need for compact and shorter combustors than are used in current technologies.
Optimization Approach for Wind Farm Cable Layout Based on Iterative Self-Organizing Data Analysis Technique Algorithm and Swap Sequence Based Particle Swarm Algorithms
Authors: Yu Deqi , Li Ming
Published: October 2022

In the fast evolving and increasingly competitive wind energy market, to minimize initial capex and maximize production profits are essential when designing a wind farm. The electrical cable accounts for around 10% of the total capex, reasonable layout of cable connections might induce significant reduction of electrical and construction cost. In this paper, the Fuzzy C-means (FCM) clustering algorithm is adopted to determine the location of the substation(s) and the ISODATA (Iterative Self-Organizing Data Analysis Technique Algorithm) is employed to divide the wind farm into finite sub-domains, effectively reducing the complexity of the NP-hard (Non-deterministic polynomial-time hard) problem of cable layout optimization. The optimal cable layout in each sub-domain is obtained through the swap sequence based particle swarm optimization (SSPSO) and practical electrical constraints, while the objective function is to minimize the total cable costs, including material cost and cable laying cost. Current study highlights both applicability of clustering algorithm and particle swarm optimization to the cable layout problem in wind farm.
Validation of Broadband Noise Prediction Methodology Based on Linearised Navier-Stokes Analyses
Authors: Blazquez-Navarro Ricardo , Corral Roque
Published: October 2022

This paper presents an integral validation of a synthetic turbulence broadband noise prediction methodology for Fan/Outlet-Guide-Vane (OGV) interaction. The test vehicle is the ACAT1 fan, a modern scaled-down fan, experimentally analysed in 2018 within the TurboNoiseBB project. Three operating points, namely Approach, Cutback, and Sideline, and two different rig configurations in terms of the axial gap between the fan and OGV are examined within this work. The methodology consists of using a RANS solver to model the fan wake and the use of two-dimensional frequency-domain linearised Navier-Stokes simulations to resolve the acoustics, including quasi-3D corrections to obtain representative results. The RANS results with no ad-hoc tuning are compared in detail against hotwire data to determine the degree of uncertainty incurred by this kind of approach. The predicted broadband noise spectra and noise azimuthal decompositions are compared against the experimental data. The spectral levels are well predicted, despite an average under-prediction of around 3dB. The noise azimuthal decompositions feature a remarkable agreement with the experiment, denoting accurate modelling of the main physics governing the problem. The impact of increasing the fan/OGV axial gap is quantified numerically for the first time. It is concluded that increasing the gap is detrimental for the broadband noise footprint, unlike intuitively could be expected. Overall, the presented broadband noise methodology yields robust broadband noise predictions at an industrially-feasible cost and enables a deeper understanding of the problem.
On the Pneumatic Hammer of Hybrid Gas Bearings: Measurements and Predictions
Authors: Jung Hyunsung , Sin Seki , Kim Kyuman , Heo Junwon , Wee Minsoo , Ryu Keun
Published: October 2022

Hybrid bearings integrating an external pressurizing source are widely used in high-speed turbomachinery due to their notable advantages, including low friction and wear, enhanced reliability and durability, and accurate rotor positioning, as well as large static stiffness and load carry capacity even lubricated with low viscosity liquids. This paper reports experimental data and predictions to identify the characteristics of pneumatic hammer of hybrid gas bearings, 60 mm in diameter, with increasing feed gas pressures. Pneumatic hammer characteristics with static load stiffnesses and flow rates of the test bearing are recorded for increasing static loads with various shaft center positions. A computational program for modeling of hybrid gas bearings predicts static load characteristics of the test bearings. Predictions show a remarkable agreement with measurements. Comparisons of measurements and predictions reveal that calculated reduced damping factors and damping coefficients of hybrid bearings, relying on volume ratio between recess and fluid film, are reliable indicators to estimate the onset condition of pneumatic hammer instability.
Numerical Study of Roughness Effect on Performances in Representative Heat Exchanger Channels
Authors: Jabbour Joseph , Serret Damien , Yassin Hussein
Published: October 2022

Heat exchangers (HX) are vital elements specially to improve the performance of thermal and energetic cycles. It can be obtained by reducing induced pressure drop or by increasing compactness and heat transfer efficiency. The HX designers always tend to develop a new architecture with thermal enhancement tools. In this context, Additive manufacturing (AM) offers the opportunity to reach new performances and integrations through the development of innovation geometries of HX.

For the last 10 years, AM was explored producing compact and efficient thermal components. This has led to the improving the process and the ability to manufacture complex and very thin structures. In parallel, new design software and new design methodologies have been developed such as generative design or implicit CAD modeler. This imposes the development of new innovative heat transfer intensification structures based on local heat transfer and CFD analysis.

A dedicated analysis was focused on the surface roughness impact. The generated roughness with AM can be substantially larger than with conventional manufacturing process. Moreover, wall roughness varies according to their orientation based on the main direction of printing. This parameter was taken into consideration during fins optimization in both experimental or numerical work.

This paper investigates both approaches and presents comparative studies in term of numerical and experimental characterizations.
Multidisciplinary Optimization of Radial Outflow Turbines With Highly Deformable Blades
Authors: Governo André , Saracoglu Bayindir H.
Published: October 2022

Miniature radial outflow turbines are used to generate onboard power for various aerial devices using the ram effect. The incoming air flow axially entering the inlet conduit of the turbine housing spins the turbine rotor, which may have excessive tip gap and a sizable hub cavity, and radially discharges from the turbine flow passages. The current class of turbine rotors under investigation are typically made of polymeric materials for serial production at reduced cost. The turbine airfoils are designed with significant overhanging sections over the large hub cavity. Such configuration allows regulating the rotational speed of the rotor, at high inlet velocity conditions, by enabling the rear part of the blades to bend under the effect of centrifugal and fluidic forces. However, such deflections may lead to material non-linearities and strongly affect the flow development through the blade passages, which are not yet documented in the open literature. This paper investigates the complex flow field inside such turbines for a wide range of operating conditions. A multidisciplinary design optimization routine was utilized to assess the conflicting influence of the aerodynamical and structural performance for this class of turbines. The strategy utilizes an in-house metamodel-assisted optimizer (CADO) based on artificial neural networks and genetic algorithms to maximize the power output while evaluating the impact of the rotational speed on blade displacement and flow behaviour. A decoupled fluid-structure interaction approach was established in the computational fluid dynamics solver integrated with the optimizer. The methodology validation was achieved through the experimental results on high-speed blade deformation of the initial turbine mockup. The results show striking changes to turbine geometry mainly dictated by the centrifugal force as compared to the fluidic loads play when a hub cavity exists. A change in the blade loading is identified due to the three-dimensional geometric modifications of the rotor under load solicitations and connected with a modification of the incidence angle and profile curvatures. Such a process decreases the turbine’s efficiency, especially at very high rotational speeds. The results of this work provide a comprehensive design space and guidelines on the development of radial outflow turbines through the extensive optimization study for preliminary design choices for turbines with similar geometries.
Evaluation of Various Numerical Methods for Blade Row Interaction in Turbomachinery
Authors: Liu Yangwei , Yong Xiaosong , Tang Yumeng
Published: October 2022

The flow within turbomachinery is inherently unsteady, thereby the unsteady rotor-stator interaction usually has a large effect on the performance of multistage turbomachines. However, fully unsteady simulations are still too time-consuming for in the routine design of turbomachinery, thus, the steady simulation with mixing-plane method that neglects the interaction is still widely used. Some reduced-order unsteady methods, such as harmonic balance (HB) method and space-time gradient (STG) method, have been proposed to simulate the unsteady periodic flow for the purpose of reducing CPU time consumption with sufficient accuracy. In this work, four mixing-plane methods, the HB method, and the STG method are implemented into the open source CFL3D solver. Effect of these methods on predicting unsteady rotor-stator interaction are evaluated in two flow cases, including a quasi-three-dimensional radial slice of a turbine stage and a 1.5-stage high-speed axial compressor. Results show that both the high-order HB and STG methods own the similar ability as the conventional unsteady simulation in predicting the wake transmitting from upstream to downstream, while the steady mixing-plane methods fail. Numerical results of the 1.5 stage compressor show that the wake of the first row can reach the third blade row. And this phenomenon can be also clearly captured by HB and STG methods. Fourier analysis method is used to analyze the interaction in different blade rows to evaluate various numerical methods.
Breaking-Up Sedentary Behavior and Detraining Effects on Glycemic Control: A Randomized Crossover Trial in Trained Older Adults
Authors: Correia Inês R. , Magalhães João P. , Júdice Pedro B. , Hetherington-Rauth Megan , Freitas Sofia P. , Lopes Júlia M. , Gama Francisco F. , Sardinha Luís B.
Published: October 2022

In a randomized crossover trial, we examined the effects of interrupting sedentary behavior on glycemic control in trained older adults, before and after 2 weeks of detraining. Fourteen participants (65–90 years old) completed two 7-hr conditions before and after 2 weeks of detraining: (a) uninterrupted sitting (SIT) and (b) sitting plus 2 min of moderate-intensity activity every 30 min (INT). Both before and after detraining, no differences were observed for 7-hr glucose area under the curve (7 hr AUC) and mean glucose between sitting plus 2 min of moderate-intensity activity and uninterrupted sitting conditions. After detraining and for the SIT condition, higher values of 7-hr AUC (p = .014) and mean glucose (p = .015) were observed, indicating worsened glycemic control. No changes were observed in INT condition between both time points. Frequent interruptions in sedentary behavior had no effect on glycemic control, prior to or after detraining. Even so, older adults experiencing a short-term detraining period should avoid prolonged bouts of sedentary behavior that may jeopardize their glycemic control.
Fashion Versus Comfort: Exploring the Gendered Marketing Messages of Sport Team Licensed Merchandise
Authors: Sveinson Katherine , Hoeber Larena
Published: October 2022

Sport team licensed merchandise plays an important role in sport fan experiences. Existing work has explored how consumers perceive these items, motivation and consumption habits, and intent to purchase. Extending upon the performative sport fandom framework, this study explores the marketing messages of sport fan merchandise, and the resulting implied gendered and fan performances. Employing a multimodal critical discourse analysis, we analyzed the top 20 T-shirts for men and women for five National College Athletic Association institutions on their official ecommerce sites. By examining the text descriptions, visual images, and messages perceived when combining text and visuals, we found that the marketing messages of clothing items rely heavily on traditional discourses of femininity and masculinity, placing gender performances as more relevant to fan performances for women. Atypical designs suggest alternative gender and fan performances but continue to indicate that gender identity is central to clothing appearance and messaging to consumers.
Intermediate cells of in vitro cellular reprogramming and in vivo tissue regeneration require desmoplakin
Authors: Ha Jeongmin , Kim Bum Suk , Min Byungkuk , Nam Juhyeon , Lee Jae-Geun , Lee Minhyung , Yoon Byoung-Ha , Choi Yoon Ha , Im Ilkyun , Park Jung Sun , Choi Hyosun , Baek Areum , Cho Sang Mi , Lee Mi-Ok , Nam Ki-Hoan , Mun Ji Young , Kim Mirang , Kim Seon-Young , Son Mi Young , Kang Yong-Kook , Lee Jeong-Soo , Kim Jong Kyoung , Kim Janghwan
Published: October 2022

Amphibians and fish show considerable regeneration potential via dedifferentiation of somatic cells into blastemal cells. In terms of dedifferentiation, in vitro cellular reprogramming has been proposed to share common processes with in vivo tissue regeneration, although the details are elusive. Here, we identified the cytoskeletal linker protein desmoplakin (Dsp) as a common factor mediating both reprogramming and regeneration. Our analysis revealed that Dsp expression is elevated in distinct intermediate cells during in vitro reprogramming. Knockdown of
Dsp
impedes in vitro reprogramming into induced pluripotent stem cells and induced neural stem/progenitor cells as well as in vivo regeneration of zebrafish fins. Notably, reduced
Dsp
expression impairs formation of the intermediate cells during cellular reprogramming and tissue regeneration. These findings suggest that there is a Dsp-mediated evolutionary link between cellular reprogramming in mammals and tissue regeneration in lower vertebrates and that the intermediate cells may provide alternative approaches for mammalian regenerative therapy.
A population-based cohort study of traffic congestion and infant growth using connected vehicle data
Authors: Willis Mary D. , Schrank David , Xu Chunxue , Harris Lena , Ritz Beate R. , Hill Elaine L. , Hystad Perry
Published: October 2022

More than 11 million Americans reside within 150 meters of a highway, an area of high air pollution exposure. Traffic congestion further contributes to environmental pollution (e.g., air and noise), but its unique importance for population health is unclear. We hypothesized that degraded environmental quality specifically from traffic congestion has harmful impacts on fetal growth. Using a population-based cohort of births in Texas (2015–2016), we leveraged connected vehicle data to calculate traffic congestion metrics around each maternal address at delivery. Among 579,122 births, we found consistent adverse associations between traffic congestion and reduced term birth weight (8.9 grams), even after accounting for sociodemographic characteristics, typical traffic volume, and diverse environmental coexposures. We estimated that up to 1.2 million pregnancies annually may be exposed to traffic congestion (27% of births in the United States), with ~256,000 in the highest congestion zones. Therefore, improvements to traffic congestion may yield positive cobenefits for infant health.
Clinically relevant treatment of PDX models reveals patterns of neuroblastoma chemoresistance
Authors: Mañas Adriana , Aaltonen Kristina , Andersson Natalie , Hansson Karin , Adamska Aleksandra , Seger Alexandra , Yasui Hiroaki , van den Bos Hilda , Radke Katarzyna , Esfandyari Javanshir , Bhave Madhura Satish , Karlsson Jenny , Spierings Diana , Foijer Floris , Gisselsson David , Bexell Daniel
Published: October 2022

Chemotherapy resistance and relapses are common in high-risk neuroblastoma (NB). Here, we developed a clinically relevant in vivo treatment protocol mimicking the first-line five-chemotherapy treatment regimen of high-risk NB and applied this protocol to mice with
MYCN
-amplified NB patient-derived xenografts (PDXs). Genomic and transcriptomic analyses were used to reveal NB chemoresistance mechanisms. Intrinsic resistance was associated with high genetic diversity and an embryonic phenotype. Relapsed NB with acquired resistance showed a decreased adrenergic phenotype and an enhanced immature mesenchymal–like phenotype, resembling multipotent Schwann cell precursors. NBs with a favorable treatment response presented a lineage-committed adrenergic phenotype similar to normal neuroblasts. Novel integrated phenotypic gene signatures reflected treatment response and patient prognosis. NB organoids established from relapsed PDX tumors retained drug resistance, tumorigenicity, and transcriptional cell states. This work sheds light on the mechanisms of NB chemotherapy response and emphasizes the importance of transcriptional cell states in chemoresistance.
Long-lived plasma cells accumulate in the bone marrow at a constant rate from early in an immune response
Authors: Robinson Marcus James , Dowling Mark R. , Pitt Catherine , O’Donnell Kristy , Webster Rosela H. , Hill Danika L. , Ding Zhoujie , Dvorscek Alexandra R. , Brodie Erica J. , Hodgkin Philip D. , Quast Isaak , Tarlinton David Mathew
Published: October 2022

Vaccines work largely by generating long-lived plasma cells (LLPCs), but knowledge of how such cells are recruited is sparse. Although it is clear that LLPCs preferentially originate in germinal centers (GCs) and relocate to survival niches in bone marrow where they can persist for decades, the issues of the timing of LLPC recruitment and the basis of their retention remain uncertain. Here, using a genetic timestamping system in mice, we show that persistent PCs accrue in bone marrow at an approximately constant rate of one cell per hour over a period spanning several weeks after a single immunization with a model antigen. Affinity-based selection was evident in persisting PCs, reflecting a relative and dynamic rather than absolute affinity threshold as evidenced by the changing pattern of V
H
gene somatic mutations conveying increased affinity for antigen. We conclude that the life span of persistent, antigen-specific PCs is in part intrinsic, preprogrammed, and varied and that their final number is related to the duration of the response in a predictable way. This implies that modulating vaccines to extend the duration of the GC reaction will enhance antibody-mediated protective immunity.
Supplemental Material: Permian–Middle Triassic floral succession in North China and implications for the great transition of continental ecosystems
Authors: Shu Wenchao , Tong Jinnan , Yu Jianxin , al. et
Published: October 2022

Description of studied sections, biostratigraphy of Lopingian–Middle Triassic in North China, the results of statistical analysis, R scripts, and Supplementary Data Files: (1) Geological distributions of fossil plants, sporomorphs and fossil woods; (2) Detailed descriptions of floras in North China; (3) Plant genera distributions and number of genera in each stratigraphic unit; (4) Plant zones, subzones and assemblages from Cisuralian to Anisian in North China; (5) Invertebrate genera distributions and number of genera in each stratigraphic unit; (6) Insect genera distributions and number of genera in each stratigraphic unit; (7) Vertebrate genera distributions and number of genera in each stratigraphic unit; (8) Global floral changes from Lopingian to Middle Triassic; (9) Hygrophyte, mesophytes and xerophyte element distributions; (10) Hygrophte and Xerophyte ratios.
Apoptotic Processes Precede Infection with Symbionts in a Pogonophoran Lavrae (Siboglinidae, Annelida)
Authors: Rimskaya-Korsakova N. N. , Temereva E. N. , Malakhov V. V.
Published: October 2022

The fine structure of the body wall and gut was for the first time studied in the competent larvae of the frenulate pogonophoran Siboglinum fiordicum. Mass apoptosis of cell nuclei was observed in the dermo-muscular body wall and coelomic epithelium. Apoptotic nuclei were found in both cell cytoplasm and outside of the larval body. In the latter case, each nucleus was surrounded by the plasmalemma, and the entire cluster was covered with the cuticle. Cells of the larval gut retained the usual structure with the cytoplasm filled with numerous yolky granules and the nucleus displaying usual morphology. Similar apoptotic processes have been described in vestimentiferans and found to be initiated by penetration of symbiotic bacteria through the integument into the dorsal mesentery. The process of apoptotic rearrangement of body wall cells and the formation of unique symbiosis with bacteria were assumed to be time-spaced in S. fiordicum, occurring sequentially rather than simultaneously, unlike in vestimentiferans.
Global diabetes burden: analysis of regional differences to improve diabetes care
Authors: Bour Charline , Ahne Adrian , Aguayo Gloria , Fischer Aurélie , Marcic David , Kayser Philippe , Fagherazzi Guy
Published: October 2022

Introduction

The current evaluation processes of the burden of diabetes are incomplete and subject to bias. This study aimed to identify regional differences in the diabetes burden on a universal level from the perspective of people with diabetes.

Research design and methods

We developed a worldwide online diabetes observatory based on 34 million diabetes-related tweets from 172 countries covering 41 languages, spanning from 2017 to 2021. After translating all tweets to English, we used machine learning algorithms to remove institutional tweets and jokes, geolocate users, identify topics of interest and quantify associated sentiments and emotions across the seven World Bank regions.

Results

We identified four topics of interest for people with diabetes (PWD) in the Middle East and North Africa and another 18 topics in North America. Topics related to glycemic control and food are shared among six regions of the world. These topics were mainly associated with sadness (35% and 39% on average compared with levels of sadness in other topics). We also revealed several region-specific concerns (eg, insulin pricing in North America or the burden of daily diabetes management in Europe and Central Asia).

Conclusions

The needs and concerns of PWD vary significantly worldwide, and the burden of diabetes is perceived differently. Our results will support better integration of these regional differences into diabetes programs to improve patient-centric diabetes research and care, focused on the most relevant concerns to enhance personalized medicine and self-management of PWD.
Use of equity-informed social media COVID-19 risk communication tools: a scoping review protocol
Authors: Kothari Anita , Peter Nedra , Donelle Lorie
Published: October 2022

Introduction

Health agencies and community organisations play a crucial role in disseminating information to the public about COVID-19 risks and events, providing instructions on how to change behaviour to mitigate those risks, motivating compliance with health directives and addressing false information. Social media platforms are a critical tool in risk communication, providing a medium for rapid transmission of messages as well as providing the opportunity for engagement and immediate feedback. Access to health information, services and support are especially important for marginalised and underserved (‘equity-deserving’) populations who are disproportionately affected by COVID-19. This scoping review aims to review the breadth and depth of the academic and grey literature on equity-informed social media risk communication tools to provide guidance on promising practices and principles for reaching equity-deserving populations through social media.

Methods and analysis

Arksey and O’Malley’s (2005) framework guided the identification of the research question; identification and selection of relevant studies from electronic databases and hand-searches of discipline-specific journals; extraction and charting of the data; and collating and reporting of findings. The results of the screening process will be reported using the Preferred Reporting Items for Systematic Review and Meta-Analysis-Scoping Review guidelines.

Findings

We will identify reported facilitators and barriers to the development of risk communications that target equity-deserving communities. We will also identify recommendations for equity-informed risk communication for COVID-19.

Ethics and dissemination

This study does not require ethics approval. We intend to disseminate the results through publication in an open-access peer-reviewed journal, conference presentations, lay summaries (eg, checklists) for health organisations and messages to be shared through social media.