bluuebunny/crossref_metadata_2025_split huggingface dataset:
Asymptotic enumeration of graphical regular representations
Authors: Xia Binzhou , Zheng Shasha 
Published: September 2023

AbstractWe estimate the number of graphical regular representations (GRRs) of a given group with large enough order. As a consequence, we show that almost all finite Cayley graphs have full automorphism groups ‘as small as possible’. This confirms a conjecture of Babai–Godsil–Imrich–Lovász on the proportion of GRRs, as well as a conjecture of Xu on the proportion of normal Cayley graphs, among Cayley graphs of a given finite group.
Opportunities for Integrating Particle-Based Concentrated Solar Power Generation With a Fluidized Desalinating Heat Exchanger: A Technoeconomic Analysis
Authors: Brooks Joshua D. 
Published: September 2023

Abstract
The World is drifting closer to a future of unparalleled water resource management challenges. Rising global population, agriculture production, and energy demand have driven a projected increase in annual global water demand to an estimated 6,000 km3 by 2050, accounting for approximately 11% of the world’s annual renewable water resources 1–5. Accordingly, water stress is expected to double in the next 30 years, leading to disrupted societies, a change in the global landscape, and a clear threat to national security 6–7. On top of this, reliance on traditional carbon-based energy, ∼86% of the global mix in 2018, has helped produce the World’s current climate crisis 8. Failure to decarbonize our continuously increasing energy production will continue to stress humans and critical systems 6.
Water desalination, removing salt from water, and concentrated solar power (CSP) systems offer partial solutions to the world’s water and energy resource issues, respectively. However, seawater desalination is currently too expensive, water and energy inefficient, and carbon intense 9–10. Likewise, CSP systems are currently expensive, suffer in part from solar intermittency, and consume immense amounts of cooling water 11–12. This paper aims to combat the disadvantages of desalination and CSP systems by investigating the opportunity for integrating these. Specifically, a techno-economic analysis it performed to estimate the efficacy of various integration approaches. Among these, the evaluated case study identified the lowest cost system resulting from the integration of a thermal desalination plant which is thermally driven by a CSP plant’s waste heat and is electrically driven by excess power generated by augmenting the design output of the same CSP plant.
Pore-Scale Simulation of a Tubular Solar Absorber Partially Filled With Raschig Ring Porous Medium for Efficiency Enhancement Purposes
Authors: Ebadi Hossein , Cammi Antonio , Fathi Nima , Savoldi Laura 
Published: September 2023

Abstract
This study considers a partial filling of a novel porous insert to ease the burden of the excessive pressure drop and customize the porous structure with the absorbed flux distribution in a tubular solar absorber. This arrangement would suggest an enhanced porous integration with solar absorbers, in which the fraction of porous material with higher thermal contribution is kept, while the side with lower heat contribution is removed to maintain the pressure drop at low levels. To achieve this goal, a numerical investigation was performed on a novel porous medium made of metallic Raschig Rings (RR), with three different filling percentages of 10, 20, and 30% of the tube cross-section. Simulations were conducted using CFD and validated against the experimental data acquired for a 100% RR porous filling in a tubular absorber tested in a solar furnace. Up to an 80% increase in the pressure drop was observed using partial filling instead of a clear tube while the heat transfer performance in terms of Nu was improved up to &gt; 20%. Moreover, studying the fluid behavior in the porous and non-porous regions revealed that the fluid in the porous zone is pushed away from the matrix into the non-porous region, making a complex behavior at this interface. The influences of different filling percentages on the flow behavior at the interface and the consequence cooling effects on the absorber are also addressed.
Co-Gasification of Gypsum and Municipal Solid Waste Components in CO2 Atmosphere
Authors: Mavukwana Athi-Enkosi , Burra Kiran Raj Goud , Sempuga Baraka Celestin , Gupta Ashwani 
Published: September 2023

Abstract
In the United States, only 12% of the 284 million tons of municipal solid waste (MSW) generated per annum is currently processed for energy recovery. The limitations to processing more MSW for energy recovery include concern of pollutants emission from the current facilities, high investment cost, low product and economic value and thus economic competition with landfilling. The landfilling is not sustainable so that a permanent solution is urgently required. In this paper, we examine the synergistic potential of incorporating gypsum wastes from construction and demolition sector into the CO2 assisted gasification of municipal solid waste. The effect of varying proportions of gypsum during the co-gasification of gypsum with MSW mixture and individual components (wood and polyethylene terephthalate (PET)) using CO2 as the gasification agent was investigated. The results showed that an increase in gypsum proportion in MSW affected the syngas yield. The yield was reduced by 35% when gypsum was added at equal mass proportions (1:1) to MSW. Adding gypsum to wood increased the cumulative yield of syngas by 7%, and the optimum syngas yield was achieved at a 5:1 ratio of wood to gypsum. The yield of syngas also reduced with an increase of gypsum addition to PET. However, the syngas quality was improved with gypsum addition as the yields of hydrocarbon were reduced. Gypsum increased the syngas yield by 25% more for wood than that of MSW and 60% more than PET. This suggests that the feedstock components with a charring tendency to have greater yields of syngas with gypsum addition. This is attributed to gypsum reaction with char intermediates in a solid-solid reaction along with the reaction of CO2 + C = CO to produce CO that has a significant impact on the syngas yield compared to the oxidation of volatiles by gypsum.
Investigations of End-Plates of Various Widths on the Performance of an Optimized Airfoil
Authors: Torres Leovigildo , Rahai Hamid 
Published: September 2023

Abstract
Steady numerical simulations of an optimized airfoil [1, 2] with different-sized end plates have been performed to identify the effect of chord-shaped end plates with different widths on its lift and drag forces. The freestream mean velocity was 10 m/sec. and the Reynolds number based on the airfoil chord length was approximately 2.0 × 105. The new end plates have a width of 1.27, 7.62, or 12.7 cm. The results of the airfoil without the end plates have shown increased lift with increasing the angle of attack (AOA) with a peak lift coefficient of 1.9 and the lift-to-drag ratio was 2.8 at 20 degrees AOA. The addition of the end plates respectively increases and decreases the lift and drag forces with 12.7 cm width end-plates being the most impactful, resulting in a nearly 9.1% increase and over 30% decrease in the lift and drag forces respectively as compared with the corresponding results for the baseline model. For the 1.27 cm width end-plates, the average increase and decrease in respectively lift and drag forces were 5.7% and less than 1% and when the 7.62 cm width end-plates were used these values were 8.2% and over 24%. For all models, there were no significant increases in lift force beyond 40 degrees AOA.
Metals Recovery and Syngas Evolution During Co-Gasification of Municipal Solid Waste and Gypsum
Authors: Mavukwana Athi-Enkosi , Burra Kiran Raj Goud , Sempuga Baraka Celestin , Gupta Ashwani 
Published: September 2023

Abstract
Thermodynamic equilibrium analysis is used to investigate the transformation of metals during the co-gasification of municipal solid waste (MSW) and gypsum (CaSO4). Aspen Plus is combined with Thermo-calc to develop a process model that considers the conversion of metals. The effect of air ratio, temperature, and feed mass ratio (MSW to gypsum) on the syngas evolution and mineral transformation behavior is investigated. The results showed that temperatures below 1050°C, air ratio &lt; 0.4, and MSW to CaSO4 feed mass ratio &gt; 2.5 prevented the gypsum sulfur transformation to sulfur dioxide. About 90 wt% of the products were gases comprising 22% CO and 19% H2. At about 900°C the major minerals formed were CaS (alabandite), melilite, anorthite, rankinite, nepheline, and wollastonite. Melilite, a calcium silicate of aluminum and magnesium, dominated over all other silicates. However, at temperatures &gt; 1000°C, these minerals transform into a more stable calcium orthosilicate (CaSiO4) and molten oxysulfide. Above 1200°C all metals in MSW were transformed into molten oxides. The results show that syngas and minerals can be recovered during the co-gasification of MSW and gypsum revealing the synergetic benefits of co-processing two different low-value waste materials.
A Design Study of an Elasto-Hydrodynamic Seal for sCO2 Power Cycle by Using Physics Informed Neural Network
Authors: Rimon Mohammad Towhidul Islam , Hassan Mohammad Fuad , Lyathakula Karthik Reddy , Cesmeci Sevki , Xu Hanping , Tang Jing 
Published: September 2023

Abstract
Supercritical carbon dioxide (SCO2) is a promising alternative working fluid in power cycles. It offers several benefits, including improved efficiencies, lower power costs, lower water usage, and reduced equipment footprint. At the subcomponent level, there is a lack of suitable shaft end seals to minimize the sCO2 leakage in the turbomachinery, which would otherwise penalize the efficiencies by up to 0.65 percent, for example, for a 500 MWe utility-scale power plant when existing sealing technologies are used such as labyrinth seals. For a potential solution, we propose a simple sleeve-like Elasto-Hydrodynamic (EHD) seal concept that provides low leakage, minimum wear, and no stress concentration. In this work, a numerical study has been performed to model the structural deformation of the EHD seal and fluid flow by using Lame’s equation and simplified Reynold’s equation, respectively. However, the analytical solutions for this type of modeling require a set of coupled differential and highly non-linear equations. Conventional approaches for optimizing the solution often end in convergence issues and require selecting specific flow rates. Therefore, the design equations used in this work have been solved by adopting the Physics Informed Neural Network (PINN) to mitigate these issues. Through using PINN analysis, the throttling behavior of the seal was successfully demonstrated. The deformation of the seal was observed to occur at an axial length of approximately 18mm, while a fixed root condition was imposed at 26.5mm. The initial clearance within the seal was 0.2566mm, but it was observed to decrease as the pressure increased within the range of 60MPa to 90MPa.The fluid flow inside the region also decreased from 0.68kg/s to 0.42kg/s at this high-pressure range. The proposed analysis can be used to design EHD seals for specific cases when more comprehensive simulation models are not readily available or are deemed to be costly.
Start-Up Operation Strategy Optimization of the Solar Field for a Parabolic Trough Concentrated Solar Power Plant
Authors: Zhang Shunqi , Tang Haiyu , Liu Ming , Liu Jiping , Yan Junjie 
Published: September 2023

Abstract
Parabolic trough concentrated solar power (PTCSP) undergoes daily start-ups and shut-downs despite integrating thermal energy storage (TES). The PTCSP start-up process reduces its annual electricity production of PTCSP by 10% to 20% and increases its levelized cost of energy. An energetic analysis of a 50 MW PTCSP shows that nearly 30% of start-up energy loss has energy-saving potential by optimizing the system configuration or operational strategy. However, research on reducing the start-up energy consumption of PTCSP does not draw enough attention. Here, the start-up strategy of the receiver was optimized to reduce the start-up energy consumption. The receiver is divided into two sections with different start-up strategies. The start-up strategy of the first section employs the conventional receiver start-up strategy, and the start-up strategy of the other section is modified based on the power block start-up curve, which reduces the receiver temperature of the solar field. The results indicate that the energy and exergy of TES can be improved by 9.4% and 11.4%, respectively, by optimizing the receiver start-up strategy. The annual electricity production can be improved by 171.1 MWh (∼0.1%), and the annual net income is approximately 30000 $ when the feed-in tariff is 16.4 ¢·kWh−1.
Using Simulation and Experiment to Develop a Design Methodology for Self-Shaping Solid Oxide Fuel Cell Multilayer Ceramic Composites
Authors: Hartwell Alexander R. , Elsayed Saifeldeen K. , Qin Zhao , Ahn Jeongmin 
Published: September 2023

Abstract
Traditional ceramic manufacturing techniques offer a limited assortment of achievable 3D geometries. For multilayer ceramic composites, such as solid oxide fuel cells, this is further limited to only planar and tubular forms. While there has been interest in a variety of advanced manufacturing techniques such as 3D printing, a less conventional option has also gained interest. Self-shaping of multilayer ceramic composites utilizing mismatched thermal expansion coefficient driven bilayer shrinkage is an alternative manufacturing strategy which circumvents many issues associated with other techniques. In this process, a tape cast substrate is sprayed with a patterned or uniform film which contracts relative to the substrate while cooling from the peak sintering temperature to room temperature resulting in controlled deformation. Reliably predicting the final 3D geometry for any arbitrary combination of 2D substrate shape and film pattern is nontrivial, and disagreement between the degree of curvature predicted from theory and that observed from experiment complicate the adoption of this manufacturing strategy.
This work looks at several geometries for which these scaling laws have already been developed and applies them to the ceramic system both through experimentation and simulation. By comparing experiment and simulation, we can modify our model to accurately represent the real material behavior. We seek to accommodate this disagreement so that we may accurately apply the above-mentioned scaling laws to efficiently design starting substrate and film.
Investigation of Ammonia as a Fuel for Solid Oxide Fuel Cells
Authors: Wilhelm Cole , Tamaoki Kenta , Nakamura Hisashi , Ahn Jeongmin 
Published: September 2023

Abstract
Decreasing the generation of CO2 from energy production is a key area in energy research and environmental sustainability. Fuel cells represent a solution to reducing CO2 generation through the use of hydrogen fuel to generate electricity. However, the widespread use of hydrogen fueled fuel cells is generally limited by difficulty of hydrogen storage, transportation, and synthesis. One promising option to address these difficulties is the use of ammonia (NH3) in solid oxide fuel cells (SOFCs), which allows for storage of a liquid fuel source, rather than the highly compressed gaseous fuel. Sourcing hydrogen from ammonia rather than from fossil fuel reformation eliminates the possibility of CO2 generation from SOFC usage. Previous work has proven the ability to generate hydrogen from ammonia at high temperatures in a micro flow reactor (MFR) at high equivalence ratio. The current work seeks to apply a similar methodology directly to standard SOFCs for electricity generation. Construction of the planar SOFC includes a nickel-yttria stabilized zirconia (Ni-YSZ) anode, YSZ electrolyte layer, samarium doped ceria (SDC) electrolyte buffer layer, and lanthanum strontium cobalt ferrite-SDC (LSCF-SDC) cathode layer. A model ammonia exhaust based on the MFR exhaust for equivalence ratio of 4 from the previous work is used. A mixture of NH3, H2, and N2 simulates the MFR exhaust and is supplied to the SOFC. N2 is used to account for all MFR exhaust species outside of NH3 and H2. Testing is completed in a tubular furnace in order to maintain a controlled temperature, with oxygen being supplied to the cathode by ambient air. The buffer-layer SOFC showed high performance on pure H2 at 1V OCV and 343mW/cm2 power density. The performance decreases on model exhaust, but maintains 0.9V OCV and 128mW/cm2 power density. This showcases the ability of SOFCs to generate power from a NH3 supply that primarily contains N2.
Novel Dilution Zone Jet Modifiers: an Experimental and Numerical Study of Combustor Temperature Uniformity
Authors: Soliman Ibrahim , Salem Abdel Rahman , Amano Ryoichi 
Published: September 2023

Abstract
This study focuses on improving the temperature uniformity of mixed gases stream within combustor dilution zones. Temperature uniformity enhancement is investigated by using passive cooling via Modifier Nozzle Parts (MNP), and Modifier Diffuser Parts (MDP) that are installed on the dilution holes. Multiple parts diameter-length scenarios are investigated to select the optimum designs for controlling the velocity and pressure of dilution jets. An experimental setup with Reynolds number (Re) ranging between 104,000 and 271,000 is used to simulate dilution gas mixing and to validate Computational Fluid Dynamics (CFD) models. Results show that lower-length MNP designs provide comparable temperature uniformity factor (χ) enhancement without the added pressure drop, which results from higher lengths — reducing the area ratio for the MNP yields lower (χ) enhancement but with a notable increase in pressure drop. The most effective design in terms of benefit to cost is the MNP design with area shrinkage ratio of quarter (1/4) and a length corresponding to half the radius (∼10 mm) of the dilution hole. This design results in χ enhancement of 6% and an added pressure drop of 9%. The MDP designs performed poorly compared to the MNP designs. The k-ε (RNG) model showed good agreement with experimental data and performed well against k-ω (SST) and Reynolds Stress Turbulence (RST) models.
An
Anaplasma phagocytophilum
T4SS effector, AteA, is essential for tick infection
Authors: Park Jason M. , Genera Brittany M. , Fahy Deirdre , Swallow Kyle T. , Nelson Curtis M. , Oliver Jonathan D. , Shaw Dana K. , Munderloh Ulrike G. , Brayton Kelly A. 
Published: September 2023

ABSTRACT

Pathogens must adapt to disparate environments in permissive host species, a feat that is especially pronounced for vector-borne microbes, which transition between vertebrate hosts and arthropod vectors to complete their lifecycles. Most knowledge about arthropod-vectored bacterial pathogens centers on their life in the mammalian host, where disease occurs. However, disease outbreaks are driven by the arthropod vectors. Adapting to the arthropod is critical for obligate intracellular rickettsial pathogens, as they depend on eukaryotic cells for survival. To manipulate the intracellular environment, these bacteria use type IV secretion systems (T4SS) to deliver effectors into the host cell. To date, few rickettsial T4SS translocated effectors have been identified and have only been examined in the context of mammalian infection. We identified an effector from the tick-borne rickettsial pathogen
Anaplasma phagocytophilum
, HGE1_02492, as critical for survival in tick cells and acquisition by ticks
in vivo
. Conversely, HGE1_02492 was dispensable during mammalian cell culture and murine infection. We show that HGE1_02492 is translocatable in a T4SS-dependent manner to the host cell cytosol. In eukaryotic cells, the HGE1_02492 localized with cortical actin filaments, which is dependent on multiple sub-domains of the protein. HGE1_02492 is the first arthropod-vector specific T4SS translocated effector identified from a rickettsial pathogen. Moreover, the subcellular target of HGE1_02492 suggests that
A. phagocytophilum
is manipulating actin to enable arthropod colonization. Based on these findings, we propose the name AteA for
Anaplasma
(
phagocytophilum
) tick effector A. Altogether, we show that
A. phagocytophilum
uses distinct strategies to cycle between mammals and arthropods.

IMPORTANCE

Ticks are the number one vector of pathogens for livestock worldwide and for humans in the United States. The biology of tick transmission is an understudied area. Understanding this critical interaction could provide opportunities to affect the course of disease spread. In this study, we examined the zoonotic tick-borne agent
Anaplasma phagocytophilum
and identified a secreted protein, AteA, which is expressed in a tick-specific manner. These secreted proteins, termed effectors, are the first proteins to interact with the host environment. AteA is essential for survival in ticks and appears to interact with cortical actin. Most effector proteins are studied in the context of the mammalian host; however, understanding how this unique set of proteins affects tick transmission is critical to developing interventions.
Nectin-3 and shed forms of CSPG4 can serve as epithelial cell receptors for
Clostridioides difficile
TcdB
Authors: Childress Kevin O. , Cencer Caroline S. , Tyska Matthew J. , Lacy D. Borden 
Published: September 2023

ABSTRACT

Clostridioides difficile
is a Gram-positive bacterium that can cause mild to severe diarrhea, inflammation, and colonic tissue damage in animal hosts. Symptoms of the disease can be attributed to the activity of toxin B (TcdB) secreted by
C. difficile
during infection. TcdB can engage multiple host cell surface receptors
in vitro
; however, little is known about where these receptors localize on colonic tissue and how these interactions promote disease. Here, we used immunofluorescence microscopy to first visualize TcdB interactions with two of the reported receptors, CSPG4 and Nectin-3, on cells
in vitro
. In cells expressing both receptors, we found that TcdB preferentially interacts with CSPG4. In moving to host colonic tissue, we observed novel localization of Nectin-3 within the brush border of epithelial cells and CSPG4 localization at epithelial cell junctions. The unexpected junctional CSPG4 signal led us to the hypothesis that the signal could represent a soluble form of the CSPG4 extracellular domain (ECD) being shed from fibroblasts in the underlying stromal layer of the tissue. To test, we set up a co-culture of epithelial cells and fibroblasts separated by transwell inserts. We observed CSPG4-ECD shed into the media of cultured fibroblasts and an accumulation in epithelial cells following co-culture. We also found that soluble CSPG4-ECD present in the conditioned media from fibroblasts can potentiate TcdB-mediated cytopathic responses in epithelial cells lacking CSPG4 expression. Based on these observations, we propose that Nectin-3 can facilitate the binding of TcdB at the epithelial surface and that a soluble form of CSPG4 derived from stromal cells can contribute to TcdB intoxication of epithelial cells
in vivo
.

Importance

Toxin B (TcdB) is a major virulence factor of
Clostridioides difficile
, a Gram-positive pathogen that is a leading cause of hospital-acquired diarrhea. While previous studies have established that TcdB can engage multiple cell surface receptors
in vitro
, little is known about how these interactions promote disease and where these receptors localize on colonic tissue. Here, we used immunofluorescence microscopy to visualize Nectin-3 and CSPG4 on tissue, revealing unexpected localization of both receptors on colonic epithelial cells. We show that Nectin-3, which was previously characterized as an adherens junction protein, is also localized to the brush border of colonocytes. Staining for CSPG4 revealed that it is present along epithelial cell junctions, suggesting that it is shed by fibroblasts along the crypt-surface axis. Collectively, our study provides new insights into how TcdB can gain access to the receptors Nectin-3 and CSPG4 to intoxicate colonic epithelial cells.