bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of a tension band fixation as an adjunct for arthrodesis of the metacarpophalangeal joint in the horse
Authors: Kadic Lawrence I. M. , Rademacher Nathalie , Liu Chin‐Chi , Leise Britta S. , McCauley Charles T. , Riggs Laura M.
Published: September 2023

Objectives

To determine the influence of a stainless‐steel cable (SSC) tension band fixation as an adjunct to a locking compression plate (LCP) for arthrodesis of the equine metacarpophalangeal (MCP) joint.

Study design

Experimental. An ex vivo biomechanical paired equine cadaver limb study.

Sample population

Five MCP joint pairs were collected from adult Thoroughbred horses, euthanized for reasons unrelated to orthopedic disease.

Methods

Each pair of MCP joints were randomly implanted with either a dorsally placed 5.5 mm LCP and a palmarly placed 2.0 mm SSC or a dorsally placed 5.5 mm LCP alone. Each construct was tested in cyclic loading followed by single cycle to failure in axial compression. Displacement at a target load of 1 kN over 3600 cycles at 1 Hz was recorded prior to single cycle to failure testing.

Results

In cyclic testing, displacement was not significantly different between the first and last 5% of testing cycles regardless of construct. Maximum displacement of each construct during cyclic testing was <1.1 mm. In single cycle testing, the observed yield point did not reveal any difference between LCP and LCP‐SSC (p = .440). The maximum load at failure was significantly higher in LCP‐SSC compared to constructs with the LCP alone (p = .046).

Conclusion

The addition of the SSC to the LCP did not statistically affect construct displacement during cyclic loading or construct yield load during subsequent single cycle to failure.

Clinical significance

This study provided much needed information regarding the necessity of a tension band SSC application in the arthrodesis of the MCP/MTP joint in horses.
Numerical Investigation of the Influence of the Degree of Reaction in an Axial Compressor Stage With Tandem Vanes
Authors: Giannini Samuele , Luz Guilherme M. , von Jeinsen Philipp , Straccia Mattia , Gümmer Volker
Published: September 2023

Many investigations have defined Smith-type diagrams to guide the preliminary designs of conventional axial compressor stages on the choice of loading, flow coefficient, and degree of reaction. However, the recent development of unconventional axial compressor stages with tandem vanes has not been accompanied by similar studies aimed at tailoring existing correlations to the new type of vanes. While it is clear that axial compressor stages with tandem vanes operate in higher working ranges than conventional stages, it is less clear how the choice of reaction affects the aerodynamic behavior of such setups. For this purpose, this paper numerically investigates a low-speed axial compressor stage with different degrees of reaction for increasing loading levels. The metal angles of the unshrouded rotor and the shrouded stator are modified to ensure that the other design parameters of the stage, namely the work and flow coefficients, are kept constant, and that the influence of the degree of reaction is isolated. The investigation begins with Q2D simulations of the reference midspan aerofoils. It then extends to a 3D configuration, while maintaining the radial distribution of the aerofoil parameters from the reference 3D blades. New correlations are presented, aiming to show how the performance of the stage in terms of efficiency, total pressure losses, and loading coefficients of the vanes are influenced by the different degrees of reaction investigated. This paper, therefore, provides insight into the preliminary choices of parameters for the design of axial compressor stages with tandem vanes.
Energy Storage Using a High-Performance Adsorption System
Authors: Vyas Animesh , Pahinkar Darshan G. , Arghode Vaibhav
Published: September 2023

Thermal energy storage systems provide cost-effective, compact, and scalable means to store heat compared to other storage systems. However, the current infrastructure of sensible storage systems suffers from low energy density and discharge at variable temperatures. In contrast, latent storage systems suffer from slow melting and solidifying of PCMs, segregation of PCM and volumetric expansion. Adsorption-based energy storage systems, when designed for fast charging and discharging, can cater to the needs of the energy storage landscape because they do not require high temperatures for regeneration while maintaining high energy density. This paper documents the computational modeling of a fast-acting thermal energy storage system employing an adsorbent-coated microchannel heat exchanger and condenser. Using microchannels results in excellent heat and mass transfer performance of the systems. The modeled system can quickly store the waste heat and release that heat very close to the inlet waste heat temperature for extended periods.
Salt Hydrate Thermochemical Energy Storage in Buildings: Analyzing Storage Density and Thermal Power Output
Authors: Barbosa Erik J. , Menon Akanksha K.
Published: September 2023

Thermochemical energy storage is promising for building applications as it offers high energy density and near-lossless storage. For example, inorganic salt hydrates that undergo reversible solid-gas thermochemical reactions can be used for thermal load shifting and/or shedding in buildings. However, this technology is still in early stages of development and drawbacks need to be addressed to make such a thermal battery viable. As salt hydrates differ in their morphology, crystal and/or particle size, and hygrothermal stability, it is critical to characterize thermochemical reactions accurately under specific operating conditions. Not only is the amount of heat delivered important, but so is the rate at which this heat is extracted for thermal end-use in buildings. However, the latter is not well reported in the literature, which is largely focused on energy storage rather than power density during the hydration reaction (battery discharge). To address this gap and the lack of standardized measurement methods, this work lays out a systematic simultaneous thermal analysis (STA) method for characterizing five different salt hydrate thermochemical materials (TCM). The effects of particle size, temperature and vapor pressure are analyzed to obtain the energy storage density and thermal power density across a full hydration-dehydration cycle under controlled conditions.
Effects of an Annular Baffle on Heat Transfer to an Immersed Coil Heat Exchanger in Thermally Stratified Tanks
Authors: Nicodemus Julia , Smith Joshua , Noreika Joseph , Gomi Manaka , Zhou Tingyu
Published: September 2023

The effect of a cylindrical baffle on heat transfer to an immersed heat exchanger is investigated in initially thermally stratified tanks. The heat exchanger is located in the annular region created by the baffle and the tank wall. Three different cases of initial thermal stratification are explored, and in each case experiments are conducted with and without the baffle in the stratified tank and in a comparable isothermal tank with the same initial energy, enabling exploration of the role of the baffle in a stratified tank and the role of stratification in tanks with or without the baffle. The baffle maintains the high initial temperature of the upper zone of the stratified tank for 10–16 minutes, as cool plumes that form on the heat exchanger are confined to the annular baffle region until they exit at the bottom of the tank. Regardless of stratification, the baffle always improves heat transfer to the immersed heat exchanger. In the isothermal tanks, the baffle increases total energy extracted in the first 30 minutes of discharge by over 20%. In stratified tanks, the baffle increases total energy extracted in 30 minutes of discharge by 9% to 16%. Initially, the improvement in heat transfer is due to the higher driving temperature differences around the heat exchanger. After all the water from the hot zone has entered and flowed through the baffle, the tank is basically isothermal, and velocity increases as the fluid temperature drops, maintaining rates of heat transfer higher than that in the tank without the baffle. Stratification improves heat transfer in tanks without a baffle because, by design, the driving temperature difference between the heat exchanger wall and the surrounding fluid is considerably higher. However, in tanks with the baffle, stratification has only a modest effect on heat transfer to the immersed heat exchanger.
Prediction of Thermionic Energy Conversion Performance and Parametric Effects Using Genetic Algorithms to Fit Physics-Inspired Model Equations to Prototype Test Data
Authors: Juette Elizabeth D. , Carey Van P. , Fleurial Jean Pierre
Published: September 2023

Several recent studies have generated experimental performance data for narrow-gap thermionic energy conversion devices. This investigation explores the use of genetic algorithm methods to fit existing data from literature with physics-inspired model equations. The resulting model equations can be used for performance prediction for system design optimization, or to explore parametric effects on performance. The model equations incorporate Richardson’s law for current density, including both the saturated and Boltzmann regimes, with appropriate relations for power delivered to the external load. The transition regime is characterized using two separate models, each accounting for non-uniformity in emission surfaces and other irregularities in the manufacturing process that impact the output power density. The trained models enable performance prediction of a small-gap thermionic energy conversion device with inputs of only emitter temperature and load resistance.

The prototype data considered here tested a thermionic energy conversion device to determine the output current and output power as a function of diode voltage and the emitter temperature. In this study, the prototype test data is used with postulated work function for the emitter and the collector materials and two additional parameters to characterize the transition region. As a result, these postulated functions are substituted into the physics-inspired models, yielding performance models with three adjustable constants. Optimized values of these constants are determined using a genetic algorithm to best fit the experimentally determined performance data for prototype thermionic conversion devices tested in earlier studies.

This process yields four insightful results. First, this work demonstrated two pathways to a model that can accurately predict performance trends. The developed models can also be used for design optimization and provide a pathway to a data-driven performance model. The two performance models each provide a method for extracting work function information from performance data. The extracted work function ultimately proves to be independent of the performance model used, as both models produce the same effective work function values for the prototype device. Finally, both of the final three-regime models illuminate the transition region between the saturated and Boltzmann regime.
Analysis of Renewable Energy Integrated Pumped Thermal Energy Storage Systems
Authors: Desai Nishith B. , Parisi Simone , Remygiakis Nikolaos , Haglind Fredrik
Published: September 2023

In this paper, a novel configuration of a pumped thermal electricity storage system is proposed which can integrate excess thermal energy from different renewable thermal energy sources, e.g. concentrated solar power, waste heat and deep geothermal energy plants, as well as excess electricity from direct electricity generating renewable energy sources, e.g. solar photovoltaic and wind energy plants. The proposed configuration can also be used as a retrofit option to existing conventional fossil fuel-based power plants. A conventional two-tank sensible heat storage is used as a thermal energy storage system that can be charged using direct renewable thermal energy and using a heat pump utilizing excess electricity. Different discharging cycles, including a Joule-Brayton system and a conventional steam Rankine cycle system, can be used. The proposed system can achieve a higher capacity factor compared to those of standalone plants.

As a case study, a conventional two-tank molten salt-based thermal energy storage system integrating concentrated solar power, considering a heliostat system, and a solar photovoltaic plant is investigated. The overall operational strategy of the plant was developed and based on that annual simulations were performed for a selected configuration. The results of the case study suggest that for a given requirement of capacity factor, the final selection of the capacities of the solar photovoltaic plant, heat pump and heliostat field should be done based on the minimum levelized cost of energy. Moreover, for high capacity factor requirements, the proposed configuration is promising.
Modelling Development of a Receiver-Reactor of Type R2Mx for Thermochemical Water Splitting
Authors: Vega Puga Estefania , Brendelberger Stefan , Weber Anika , Sattler Christian
Published: September 2023

This work reports on the development of a transient heat transfer model for a prototype reactor of type R2Mx for thermochemical water splitting by temperature and pressure swing of ceria. Key aspects of the R2Mx concept, which are also incorporated in the prototype design, include a movable monolithic redox structure combined with a linear transport system, a reduction reactor as well as a dedicated oxidation reactor. With the model, the operation of the prototype is simulated for consecutive water splitting cycles, in which ceria is reduced in a continuously heated reactor, oxidized in a separate oxidation reactor and transported in between the reaction zones.

A 2D axisymmetric numerical model of the prototype reactor was developed in ANSYS Mechanical. The model includes heat transfer calculations in combination with an approximated simulation of the transport of the redox material during cyclic operation. It incorporates the chemical reaction by means of a modified heat capacity for ceria and accounts for internal radiation heat transfer inside the porous redox material by applying effective heat transfer properties. A parametric analysis has been undertaken to evaluate different modes of operation of the oxidation reactor. Model results are used to size the power demand of the reduction reactor and vacuum pump, to define durations of the process steps as well as to assess operational parameters with respect to achieved temperatures.
Monitoring Perfusion-Based Convection in Cancer Tumor Tissue Undergoing Nanoparticle Heating by Analyzing Temperature Responses to Transient Pulsed Heating
Authors: Carlton Hayden , Korangath Preethi , Arepally Nageshwar , Attaluri Anilchandra , Ivkov Robert
Published: September 2023

The dynamic nature of perfusion in living tissues, such as solid tumors during thermal therapy, produces challenging spatiotemporal thermal boundary conditions. Changes in perfusion can manifest as changes in convective heat transfer that influence temperature changes during cyclic heating. Herein, we propose a method to actively monitor changes in local convection (perfusion) in vivo by using a transient thermal pulsing analysis. Syngeneic 4T1 tumor cells were injected subcutaneously into BALB/c mice and followed by caliper measurements. When tumor volumes measured 150–400 mm3, mice were randomly divided into one of two groups to receive intratumor injections of one of two iron oxide nanoparticle formulations for pulsed heating with an alternating magnetic field (AMF). The nanoparticles differed in both heating characteristics and coating. Intratumor temperature near the injection site as well as rectal temperature were measured with an optic fiber temperature probe. Following heating, mice were euthanized and tumors harvested and prepared for histological evaluation of nanoparticle distribution. To ascertain the heat transfer coefficient from heating and cooling pulses, we fit a lumped capacitance, Box-Lucas model to the time-temperature data assuming fixed tumor geometry and constant experimental conditions. For the first particle set, the injected nanoparticles dispersed evenly throughout the tumor with minimal aggregation, and with minimal change in convection. On the other hand, heating with the second particle generated a measurable decline in convective performance and histology analysis showed substantial aggregation near the injection site. We consider it likely that though the second nanoparticle type produced less heating per unit mass, its tendency to aggregate led to more intense local heating and tissue damage. Further analysis and experimentation is warranted to establish quantitative correlations between measured temperature changes, perfusion, and tissue damage responses. Implementing this type of analysis may stimulate development of robust and adaptive temperature controllers for medical device applications.
Approaches for Phenomenological Studies in Nucleate Boiling Using a Laser-Based Controlled Bubble Generation Technique
Authors: Dhillon Navdeep Singh , Choudhary Dilipkumar , Maree Jayden
Published: September 2023

Despite its importance in many industries, several important aspects of the nucleate boiling phenomenon remain poorly understood due to its inherent complexity and due to the statistical nature of heterogeneous bubble nucleation. This lack of understanding prevents meaningful progress in the enhancement of boiling performance parameters such as the heat transfer coefficient and the critical heat flux. To enable parametric phenomenological boiling studies, we present a laser-based controlled bubble generation technique that can produce spatially and temporally controlled bubbles representative of bubbles in actual nucleate boiling. We propose several phenomenological studies in boiling that can be undertaken using this approach to promote a mechanistic understanding of and enhancement in the boiling performance parameters.
Study on Ensemble Kalman Filter Based Building Fire Prediction and Dynamic Situation Awareness for Emergency Response
Authors: Kou Luyao , Wang Pei , Ba Rui , Liu Jiaming , Deng Qing , Zhang Hui
Published: September 2023

Numerical models provide detailed information of situation in buildings during a fire. But the models can have unsatisfactory practical performance for emergency response, due to model defects and deviations of pre-set input parameters. Data assimilation methods for error mitigation have shown great performance improvement by combining real-time measurements with fire models. However, these methods cannot revise the simulation effectively when there are obvious systematic errors between fire model and sensor readings. Ensemble Kalman filter (EnKF) is one of classical data assimilation methods. In this paper, a decentralized EnKF-based fire prediction method is proposed for the dynamic situation awareness in building fires. Individual EnKF-based fire model is established for each substructure of a building. The proposed method is less affected by systematic error of the fire model. Based on the EnKF predictions, important information of smoke and fire hazard are extracted and a fire hazard mapping is created for first responders. The multi-compartment case study validates the effectiveness of the EnKF-based fire prediction and dynamic situation awareness for emergency response.
Electron-Phonon Interactions for Nanoscale Energy Transport Simulations in Semiconductor Devices
Authors: Medlar Michael P. , Hensel Edward C.
Published: September 2023

An ideal semiconductor device would permit unimpeded flow of electrons from its source to its drain in a fashion that can be switched on and off by its gate at high frequency. Electron flow through real semiconductor devices is impeded by interactions with the crystalline structure of the material. Electrons which interact with the crystal may generate phonons which manifest as thermal energy generation and degrade real device performance from its ideal limit. Accurate simulation of electron-phonon interactions cannot rely on the traditional continuum assumption because of the reduced length and time scales of modern semiconductor devices. Allowable electron-phonon interactions are constrained by the conservation of energy and momentum. Direct enforcement of the conservation laws is achieved through computation of an interaction table that contains thousands of rows each of which representing a conservative interaction. The rows represent both phonon and electron creation and annihilation. The electron and phonon wavevector space is discretized into 65,856 elements and the table is computed by searching the discretized wavevector space for electron and phonon states that first satisfy the conservation of momentum. Subsequently, these states are compared against the conservation of energy using the phonon and electron dispersion relations. Anisotropic phonon dispersion relations were calculated using a second nearest neighbor lattice dynamics approach with interatomic force constants from Density Functional Theory. Electron dispersion relations were computed using an empirical pseudopotential approach. This method was demonstrated for computation of electron-phonon interactions in silicon, resulting in an initial interaction table containing approximately 58,000 interactions. Computation of the electron energies associated with the first conduction band in an anisotropic manner illustrate reasonable agreement with published work. The interaction densities show similar functionality relative to the electron-phonon interaction rate predictions and phonon generation rates from published literature. The interaction table directly enforces the conservation laws on all electron-phonon interactions and the interaction table approach can be used for high fidelity electron-phonon simulations to quantify the mechanism, rate, and location of thermal losses arising at the nanoscale.
Investigation of the Entropy Generation and Exergy Destruction Rates for a Novel Micro-Jet Heat Sink Working With a Nanofluid for Efficient Cooling of Motor Inverters in Electric Vehicles
Authors: Mazaheri Nima , Mwesigye Aggrey
Published: September 2023

Unlike the first law analysis which quantifies energy in systems, the second law of thermodynamics specifies the quality of energy and the direction of the processes. In this research, a novel heat sink based on micro-jet impingement for cooling inverters in electric vehicles is thermodynamically analyzed to establish the entropy generation and exergy destruction rates. The numerical simulations are performed using the finite volume method implemented in ANSYS Fluent. Numerical analyses are performed for typical motor inverter heat fluxes ranging from 100 to 300 W/cm2, Reynolds number between 5,000 and 20,000. Alumina-water nanofluid was considered with nanoparticles at concentrations of 0, 0.008, and 0.017 by volume. Results indicate that the maximum reduction in the thermal entropy generation rate is 6.65% when the nanoparticle concentration rises to 0.017. Whereas the frictional entropy generation rate increases by 73% for the same increase in nanoparticle volume fraction. Despite this, the total irreversibility drops as the concentration rises such that the highest reduction in the total irreversibility is 6.1% since the thermal entropy generation rate is the dominant source of irreversibility. With this, utilizing nanofluids decreases the exergy destruction rate leading to a lower amount of wasted energy. When the concentration is increased from 0 to 0.008 and 0 to 0.017 at a heat flux of 100 W/cm2, the optimal Reynolds numbers for maximum reduction in exergy destruction are 10,000 and 5,000, respectively.
Heat Flux Characterization From a Band Heater to Pipe Using Inverse Heat Conduction Problem Method
Authors: Peruchi Pacheco da Silva Ramon , Woodbury Keith , Samadi Forooza , Carpenter Joseph
Published: September 2023

An experimental apparatus was constructed to correlate water flow rate and temperature rise under an external band heater. Due to physical characteristics of the band heater, its transient heating behavior is unknown. This paper investigates the application of Inverse Heat Conduction Problem (IHCP) methods to characterize the heat flux from the band heater. Three experiments with different heating times (5, 10, and 20 seconds) and no flow rate were conducted to measure the transient temperature under the 400 W band heater. Type T thermocouples measure surface temperature at the centerline of the band heater. The experimental results are computed with five different heat conduction models. The models are chosen to identify how the heat flux response varies from a simplified to a realistic model. Additionally, the results of the experimental heat flux are compared to the manufacturer band heater data (58.9 kW/m2) for each model. The minimum time needed for the heater to fully energize the system is from 10 to 12 seconds. The residuals for each model are analyzed and are used to evaluate the appropriateness of the five different models.
A Numerical Study of Refrigerant Leakage From a Propane-Based Refrigeration System
Authors: Zhang Mingkan , Sharma Vishaldeep , Fricke Brian A.
Published: September 2023

Low Global Warming Potential (GWP) refrigerants, e.g. Propane (R290) (GWP = 3) and R1234yf (GWP = 4), are becoming a popular choice among refrigeration and HVAC systems, such as vending machines and air conditioning. However, most of Low GWP refrigerants are flammable (ASHRAE class A2 or A3), so safety is a very important consideration when designing and deploying low GWP refrigerants-based equipment in buildings. In the event of a refrigerant leak, the flammability of low GWP refrigerants depends on the local concentration of the refrigerant within the vicinity of the leak. In addition, the low GWP refrigerants concentration is affected by the indoor air environment, such as air flow rate and temperature. In the present study, a computational fluid dynamics (CFD) model is developed to model the flow and temperature of air surrounding a propane-based refrigeration system, as well as the concentration of leaked low GWP refrigerants surrounding the refrigeration system. The model results reveal the concentration distribution of low GWP refrigerants within the building, and as a result, the flammable regions within the building can be identified. Moreover, different ventilation layouts will be tested using the model to improve the design of ventilation. The numerical model can assist in the design of ventilation systems to minimize flammable regions within buildings due to leakage of flammable refrigerants.
Use of a Genetic Algorithm to Model the Interaction of Conduction and Nucleate Boiling Mechanisms During Evaporation of Water Droplets on Superheated ZnO Nanostructured Surfaces
Authors: Silva Anisa D. , Carey Van P.
Published: September 2023

At low surface superheat levels, water droplets deposited on ZnO nanostructured surfaces vaporize primarily by conduction transport of heat from the solid heated surface to the liquid-vapor interface. As the superheat is increased beyond the onset of bubble nucleation threshold (ONB), an increasing number of active nucleation sites are observed within the evaporating droplet reducing the time required to completely evaporate the droplet. There were two primary objectives of this investigation; first, to determine how system parameters dictate when ONB occurs and how its heat transfer enhancement effect increases with superheat. The second was to develop a physics-inspired model equation for the evaporation time of a droplet on a nanostructured surface which accounts for effects of conduction transport in the liquid layer of the droplet and nucleate boiling.

A shape factor model for conduction-dominated vaporization of the droplet was first constructed. A correction factor was introduced to account for deviation of the measured droplet evaporation times from the conduction-dominated model. The correction factor form was postulated using a modified form of the onset of nucleate boiling parameter used in the well-known model analysis developed by Hsu to predict onset of nucleation and active nucleation site range in a thermal boundary layer associated with forced convection boiling. Droplet footprint radii were experimentally observed to be affected by superheat and an additional term was introduced to account for this phenomenon. A term was also introduced to include correlations for boiling to incorporate system properties.

This modeling led to an evaporation time equation containing numerical constants dictated by the idealizations from the physical modeling. To develop an improved empirical model equation, these numerical values were taken to be adjustable constants, and a genetic algorithm was used to determine the adjustable constant values that best fit a data collection spanning wide variations of droplet size, surface apparent contact angle, and superheat level. The best-fit constants match the data to an absolute fractional error of 26%. The model equation developed in this study provides insight into the interaction between conduction transport and nucleate boiling effects that can arise in droplet vaporization processes.
Use of Artificial Intelligence Techniques, Correlation of Thermal Images and the Concept of Thermal Impedance Aiming to Estimate the Location and Size of Breast Tumours
Authors: Nascimento Jefferson G. , Menegaz Gabriela L. , Guimaraes Gilmar
Published: September 2023

Early and accurate detection of breast cancer is a critical part of the strategy to reduce mortality associated with this prevalent disease. We propose to develop techniques based on applying the thermal impedance method and artificial intelligence to detect the origin of the heat source (abnormal cancer metabolism) and its size. The low sensitivity to tiny and deep tumours, usually found when analyzing surface temperatures using thermal imaging, is circumvented by utilizing the concept of thermal impedance and artificial intelligence techniques such as deep learning. The thermal model’s development and the database’s creation based on its solution are described. It also presents the choice of detectable parameters in the thermal image, deep learning libraries and network training using convolutional neural networks. Estimates of the location and size of tumours using thermographic images obtained from simulated thermal models of a breast based on a Cartesian geometry and a scanned geometric shape of an anatomical phantom model are also described.
Prediction of the Inter-Tube Flow Mode Transitions in the Evaporators of Multi-Effect Thermal Desalination Plants
Authors: Mikhaeel Mina M. K. , Jacobi Anthony M.
Published: September 2023

Water is one of the most stressed resources on the planet. The limited availability of fresh water and the high cost of transportation have led to an increased interest in water desalination technologies. The two main categories of desalination techniques are membrane desalination and thermal desalination. Membrane technologies include pressure driven and electrical driven membranes. On the other hand, thermal desalination includes: multi-effect desalination (MED), multi-stage flash (MSF) desalination, and mechanical vapor compression desalination.

Multi-effect desalination plants are usually made of a series of evaporators (also known as effects). In each effect, hot steam flows inside the tubes and evaporates the seawater that falls on the outside of the tubes. The vapor formed at each effect flows to the next effect and acts as the heating medium for the falling seawater. The prevailing flow mode of the falling seawater (i.e. droplet, jet, or sheet) influences heat and mass transfer as well as dry out in the evaporators of Multi-Effect Desalination (MED) plants.

The objective of this paper is to predict and discuss the prevailing falling film flow modes in the evaporators of MED plants, under different operating conditions. The paper demonstrates the transitional Reynolds numbers between the main falling film modes for seawater. This closes a gap in the literature where there is a dearth of mode transition data for seawater. The effect of fluid properties and tube geometry on the transitions is discussed in details. The accuracy of the predicted transitional Reynolds numbers is evaluated via uncertainty quantification techniques.
Exploring Factors Associated With Accelerometer Validity Among Ethnically Diverse Toddlers
Authors: Crumbley Christine , Cepni Aliye B. , Taylor Ashley , Thompson Debbe , Moran Nancy E. , Olvera Norma , O’Connor Daniel P. , Johnston Craig A. , Ledoux Tracey A.
Published: September 2023

Purpose: Studying physical activity in toddlers using accelerometers is challenging due to noncompliance with wear time (WT) and activity log (AL) instructions. The aims of this study are to examine relationships between WT and AL completion and (1) demographic and socioeconomic variables, (2) parenting style, and (3) whether sedentary time differs by AL completion. Methods: Secondary analysis was performed using baseline data from a community wellness program randomized controlled trial for parents with toddlers (12–35 mo). Parents had toddlers wear ActiGraph wGT3x accelerometers and completed ALs. Valid days included ≥600-minute WT. Analysis of variance and chi-square analyses were used. Results: The sample (n = 50) comprised racial and ethnically diverse toddlers (mean age = 27 mo, 58% male) and parents (mean age = 31.7 y, 84% female). Twenty-eight families (56%) returned valid accelerometer data with ALs. Participants in relationships were more likely to complete ALs (P < .05). Toddler sedentary time did not differ between those with ALs and those without. Conclusions: We found varied compliance with WT instructions and AL completion. Returned AL quality was poor, presenting challenges in correctly characterizing low-activity counts to improve internal validity of WT and physical activity measures. Support from marital partners may be important for adherence to study protocols.
Association of Recess Provision With Accelerometer-Measured Physical Activity and Sedentary Time in a Representative Sample of 6- to 11-Year-Old Children in the United States
Authors: Clevenger Kimberly A. , McKee Katherine L. , McNarry Melitta A. , Mackintosh Kelly A. , Berrigan David
Published: September 2023

Purpose: To assess the association between the amount of recess provision and children’s accelerometer-measured physical activity (PA) levels. Methods: Parents/guardians of 6- to 11-year-olds (n = 451) in the 2012 National Youth Fitness Survey reported recess provision, categorized as low (10–15 min; 31.9%), medium (16–30 min; 48.0%), or high (>30 min; 20.1%). Children wore a wrist-worn accelerometer for 7 days to estimate time spent sedentary, in light PA, and in moderate to vigorous PA using 2 different cut points for either activity counts or raw acceleration. Outcomes were compared between levels of recess provision while adjusting for covariates and the survey’s multistage, probability sampling design. Results: Children with high recess provision spent less time sedentary, irrespective of type of day (week vs weekend) and engaged in more light or moderate to vigorous PA on weekdays than those with low recess provision. The magnitude and statistical significance of effects differed based on the cut points used to classify PA (eg, 4.7 vs 11.9 additional min·d−1 of moderate to vigorous PA). Conclusions: Providing children with >30 minutes of daily recess, which exceeds current recommendations of ≥20 minutes, is associated with more favorable PA levels and not just on school days. Identifying the optimal method for analyzing wrist-worn accelerometer data could clarify the magnitude of this effect.
Intertumoral lineage diversity and immunosuppressive transcriptional programs in well-differentiated gastroenteropancreatic neuroendocrine tumors
Authors: Hoffman Samantha E. , Dowrey Todd W. , Villacorta Martin Carlos , Bi Kevin , Titchen Breanna , Johri Shreya , DelloStritto Laura , Patel Miraj , Mackichan Colin , Inga Stephanie , Chen Judy , Grimaldi Grace , Napolitano Sara , Wakiro Isaac , Wu Jingyi , Yeung Jason , Rotem Asaf , Sicinska Ewa , Shannon Erin , Clancy Thomas , Wang Jiping , Denning Sarah , Brais Lauren , Besson Naomi R. , Pfaff Kathleen L. , Huang Ying , Kao Katrina Z. , Rodig Scott , Hornick Jason L. , Vigneau Sebastien , Park Jihye , Kulke Matthew H. , Chan Jennifer , Van Allen Eliezer M. , Murphy George J.
Published: September 2023

Neuroendocrine tumors (NETs) are rare cancers that most often arise in the gastrointestinal tract and pancreas. The fundamental mechanisms driving gastroenteropancreatic (GEP)–NET growth remain incompletely elucidated; however, the heterogeneous clinical behavior of GEP-NETs suggests that both cellular lineage dynamics and tumor microenvironment influence tumor pathophysiology. Here, we investigated the single-cell transcriptomes of tumor and immune cells from patients with gastroenteropancreatic NETs. Malignant GEP-NET cells expressed genes and regulons associated with normal, gastrointestinal endocrine cell differentiation, and fate determination stages. Tumor and lymphoid compartments sparsely expressed immunosuppressive targets commonly investigated in clinical trials, such as the programmed cell death protein–1/programmed death ligand–1 axis. However, infiltrating myeloid cell types within both primary and metastatic GEP-NETs were enriched for genes encoding other immune checkpoints, including
VSIR
(VISTA),
HAVCR2
(TIM3),
LGALS9
(Gal-9), and
SIGLEC10
. Our findings highlight the transcriptomic heterogeneity that distinguishes the cellular landscapes of GEP-NET anatomic subtypes and reveal potential avenues for future precision medicine therapeutics.
The earliest basketry in southern Europe: Hunter-gatherer and farmer plant-based technology in Cueva de los Murciélagos (Albuñol)
Authors: Martínez-Sevilla Francisco , Herrero-Otal Maria , Martín-Seijo María , Santana Jonathan , Lozano Rodríguez José A. , Maicas Ramos Ruth , Cubas Miriam , Homs Anna , Martínez Sánchez Rafael M. , Bertin Ingrid , Barroso Bermejo Rosa , Bueno Ramírez Primitiva , de Balbín Behrmann Rodrigo , Palomo Pérez Antoni , Álvarez-Valero Antonio M. , Peña-Chocarro Leonor , Murillo-Barroso Mercedes , Fernández-Domínguez Eva , Altamirano García Manuel , Pardo Martínez Rubén , Iriarte Cela Mercedes , Carrasco Rus Javier L. , Alfaro Giner Carmen , Piqué Huerta Raquel
Published: September 2023

Plant material culture can offer unique insights into the ways of life of prehistoric societies; however, its perishable nature has prevented a thorough understanding of its diverse and complex uses. Sites with exceptional preservation of organic materials provide a unique opportunity for further research. The burial site of Cueva de los Murciélagos in southern Iberia, uncovered during 19th-century mining activities, contained the best-preserved hunter-gatherer basketry in southern Europe, together with other unique organic artifacts associated with the first farming communities, such as sandals and a wooden hammer. We present 14
14
C dates for the perishable artifacts (
N
= 76), situating the assemblage between the Early and Middle Holocene (c. 7500 to 4200 cal BCE). Our integrated analysis includes raw material determination and technological and chrono-cultural contextualization of this unique and important set of materials.
Enhancing durability of automotive fuel cells via selective electrical conductivity induced by tungsten oxide layer coated directly on membrane electrode assembly
Authors: You Sang-Hoon , Jung Sang-Mun , Park Jinheon , Kim Jaerim , Kim Jong Kyu , Son Junwoo , Kim Yong-Tae
Published: September 2023

The poor durability, attributed to catalyst corrosion during start-up/shutdown (SU/SD), is a major obstacle to the commercialization of fuel cell electric vehicles (FCEVs). We recently achieved durability enhancement under SU/SD conditions by implementing a metal-insulator transition (MIT) using proton intercalation/deintercalation in WO
3
. However, such oxide-supported catalysts were unsuitable for direct application to the mass production stage of membrane electrode assembly (MEA) process due to their physical and chemical properties. Here, we report a unique approach that achieves the same durability enhancement in SU/SD situations while being directly applicable to the conventional MEA fabrication process. We coated WO
3
on the bipolar plate, gas diffusion layer, and MEA to investigate whether the MIT phenomenon was realized. The WO
3
-coated MEA demonstrated 94% performance retention during SU/SD, the highest level to our knowledge. It can directly contribute to enhancing the durability of commercial FCEVs and be immediately applied to the MEA mass production process.
Reconstructing the origin and early evolution of the snake brain
Authors: Macrì Simone , Aalto Ida-Maria , Allemand Rémi , Di-Poï Nicolas
Published: September 2023

Snakes represent one-eighth of terrestrial vertebrate diversity, encompassing various lifestyles, ecologies, and morphologies. However, the ecological origins and early evolution of snakes are controversial topics in biology. To address the paucity of well-preserved fossils and the caveats of osteological traits for reconstructing snake evolution, we applied a different ecomorphological hypothesis based on high-definition brain reconstructions of extant Squamata. Our predictive models revealed a burrowing lifestyle with opportunistic behavior at the origin of crown snakes, reflecting a complex ancestral mosaic brain pattern. These findings emphasize the importance of quantitatively tracking the phenotypic diversification of soft tissues—including the accurate definition of intact brain morphological traits such as the cerebellum—in understanding snake evolution and vertebrate paleobiology. Furthermore, our study highlights the power of combining extant and extinct species, soft tissue reconstructions, and osteological traits in tracing the deep evolution of not only snakes but also other groups where fossil data are scarce.
The presence of benzene ring activating CoA ligases for aromatics degradation in the ANaerobic MEthanotrophic (ANME) archaea
Authors: Liu Wei-Wei , Pan Piaopiao , Zhou Ning-Yi
Published: September 2023

Petroleum-source and black carbon-source aromatic compounds are present in the cold seep environments, where ANaerobic MEthanotrophic (ANME) archaea as the dominant microbial community mediates the anaerobic oxidation of methane to produce inorganic and organic carbon. Here, by predicting the aromatics catabolic pathways in ANME metagenome-assembled genomes, we provide genomic and biochemical evidences that ANME have the potential of metabolizing aromatics via the strategy of CoA activation of the benzene ring using phenylacetic acid and benzoate as the substrates. Two ring-activating enzymes phenylacetate-CoA ligase (PaaK
ANME
) and benzoate-CoA ligase (BadA
ANME
) are able to convert phenylacetate to phenylacetyl-CoA and benzoate to benzoyl-CoA
in vitro,
respectively. They are mesophilic, alkali resistance, and with broad substrate spectra showing different affinity with various substrates. An exploration of the relative gene abundance in ANME genomes and cold seep environments indicates that about 50% of ANME genomes contain PCL genes, and various bacteria and archaea contain PCL and BCL genes. The results provide evidences for the capability of heterotrophic metabolism of aromatic compounds by ANME. This has not only enhanced our understanding of the nutrient range of ANME but also helped to explore the additional ecological and biogeochemical significance of this ubiquitous sedimentary archaea in the carbon flow in the cold seep environments.

IMPORTANCE

ANaerobic MEthanotrophic (ANME) archaea is the dominant microbial community mediating the anaerobic oxidation of methane in the cold seep environments, where aromatic compounds are present. Then it is hypothesized that ANME may be involved in the metabolism of aromatics. Here, we provide genomic and biochemical evidences for the heterotrophic metabolism of aromatic compounds by ANME, enhancing our understanding of their nutrient range and also shedding light on the ecological and biogeochemical significance of these ubiquitous sedimentary archaea in carbon flow within cold seep environments. Overall, this study offers valuable insights into the metabolic capabilities of ANME and their potential contributions to the global carbon cycle.
A sensitive mass spectrometry-based method to identify common respiratory pathogens in children
Authors: Hu Lixin , Zhang Shenyan , Song Wenqi , Dong Fang , Xie Zhengde , Chen Xiangpeng , Liu Meng , Cui Baoxue , Zhang Yunheng , Zhang Rui , Wang Qingtao
Published: September 2023

Public health threats posed by emerging respiratory infections are a significant concern, particularly in children and infants. Traditional culture-based detection methods are time-consuming and typically require 1–3 days. Herein, we developed and evaluated a 23-plex common respiratory pathogen mass spectrometry assay that enables the simultaneous detection of 18 common respiratory pathogens in children. This assay combines matrix-assisted laser desorption/ionization time of flight mass spectrometry with multiplex reverse transcription-PCR and targets 11 bacterial and 7 viral pathogens (including 10 subtypes), and two internal controls. The detection limit of the common respiratory pathogen mass spectrometry assay was as low as 1 copy/µL, with no cross-reactivity with other organisms. We assessed the clinical performance of the common respiratory pathogen mass spectrometry assay using respiratory samples from 450 children. The total 450 clinical specimens underwent analysis via matrix-assisted laser desorption/ionization time of flight mass spectrometry, and the outcomes were juxtaposed with those derived from real-time reverse-transcriptase PCR conducted concurrently. The concordance between these methods was 96.0%, and the multiple infection identification rate was 7.1%. This innovative approach enables the simultaneous analysis of numerous outcomes from a solitary examination across 192 specimens within a timeframe of approximately 7 hours, with a dramatically reduced sample use and cost. In summary, the common respiratory pathogen mass spectrometry assay is a sensitive, accurate, and cost-effective method for detecting common respiratory pathogens in children and has the potential to revolutionize the diagnosis of respiratory tract infections.

IMPORTANCE

This study aimed to present and evaluate a novel co-detection method that enables the simultaneous identification of 11 bacterial and 7 viral pathogens in about 7 hours using matrix-assisted laser desorption/ionization time of flight mass spectrometry. Our approach utilizes a combination of multiplex reverse transcription-PCR and matrix-assisted laser desorption/ionization time of flight mass spectrometry, which overcomes the limitations of conventional assays, which include a long assessment time, technical difficulty, and high costs. As a screening method for common respiratory pathogens in children, common respiratory pathogen mass spectrometry assay has the potential to revolutionize the diagnosis of respiratory tract infections by providing an accurate etiological diagnosis. The common respiratory pathogen mass spectrometry assay is expected to be a critical tool for the diagnosis of respiratory infections in children, offering a more efficient, cost-effective, and accurate approach for the detection of common respiratory pathogens.