High Volume Research Articles

Epidemiological trends of febrile infants presenting to the Paediatric Emergency department, in a tertiary care hospital, Karachi, Pakistan: a retrospective review

BackgroundUnderstanding the epidemiological patterns of febrile infants can offer valuable insights for optimising management strategies and developing quality improvement initiatives, aiming to improve healthcare delivery in high-volume, low-resource emergency departments...

A simulation-based approach to analysing delays in the transport of critically ill neonates

ABSTRACT Neonatal interfacility transport ensures that critically ill neonatal patients can receive higher levels of care when needed. Delays in the transport process impact the quality of care and increase the risk of medical complications. The objective of this study is to investigate the operations-related factors that contribute to transport delays and explore the role of discrete-event simulation in improving the transport process. Semi-structured interviews were conducted with stakeholders to understand the neonatal interfacility transport process. Analysis of historical call logs and transport data was performed to identify inputs to the discrete-event simulation model. Statistical tests were used to identify the effect of various factors on wait time and transport time in the simulation model. High patient volume and limited bed capacity at the receiving hospitals are identified as bottlenecks that lead to extended wait time and transportation time. Additionally, having more geographically distributed ambulance resources does not significantly help with the time delays when the receiving hospital capacity stays unchanged. Discrete-event simulation models can be used to investigate the effects of operations-related factors in the interfacility transport of critically ill neonates to support future process improvement.

Nature-Based Secondary Resource Recovery under Climate Change Uncertainty: A Robust Multi-Objective Optimisation Methodology

The management of high-volume (HV) waste poses a persistent challenge in sustainable materials management and represents an untapped opportunity in circular economy models. This study proposes a conceptual decision-making framework to operationalise a novel circular economy strategy for HV waste, involving temporary storage to facilitate nature-based secondary resource recovery. Using an illustrative case study of a candidate HV waste (legacy mining waste), we apply a robust multi-objective spatial optimisation approach at a national scale, employing an exact solution approach. Our methodology integrates mixed-integer linear programming to evaluate the economic viability, social benefits, and impacts of climate change uncertainties on nature-based solutions (NbS) implementation across diverse scenarios. The results demonstrate that NbS can enhance economic feasibility by incorporating carbon sequestration and employment benefits while demonstrating resilience against climate change projections to ensure long-term sustainability. The findings suggest that although NbS can improve the circular economy of HV nationally, it is essential to assess additional ecosystem services and address multiple uncertainties for effective macro-level sustainability assessment of HV management. This study offers a robust decision-making framework for policymakers and stakeholders to plan and implement nature-based circular economy strategies for HV waste streams at a national level while effectively managing long-term planning uncertainties.

An Analysis of the Standardized Infection Ratio in California from 2015 to 2019: A Publicly Reported, Validated Measure of Hospital Case-mix Complexity and Quality for Surgical Site Infections in Hip Arthroplasty

The Standardized Infection Ratio (SIR), developed by the National Healthcare Safety Network (NHSN), is a validated healthcare quality outcome measure utilized by the California Department of Public Health (CDPH). Our primary goal was to use information from the SIR as measures of risk-adjusted surgical case-mix complexity and Healthcare Associated Infection (HAI) quality for surgical site infections (SSIs) in hip prosthesis (HPRO) surgery. We acquired NHSN SSI data files for HPRO surgery from 330 acute care hospitals. We categorized hospitals into 5 types (teaching, rural, community low volume, community medium volume, and community high volume) and sorted hospitals by procedure count, generating volume terciles. We multiplied each SIR and 95% confidence limits by a scale factor to allow for a comparison to the average SIR in California for the study period. The highest and lowest expected infection rates (case-mix complexity) were found in teaching hospital (0.86%) and community, high- volume hospitals (0.56%). When all non-teaching hospitals were combined, teaching hospitals treated a higher case complexity (95% Confidence Limit (CL): 0.7713 to 0.9727) than non-teaching hospitals (95% CL 0.5774, 0.6518). The lowest and highest SIR values were seen in community high volume (0.78) and rural hospitals, (1.38). The lowest- volume hospitals performed significantly worse (SIR 1.15: 95%CL 1.058-1.256) than the highest- volume hospitals (SIR 0.83: 95% CL 0.747-0.920). The SIR model developed by NHSN provides important public information about risk-adjusted surgical case-mix complexity and hospital quality for SSIs that incorporates parameters that may more accurately account for technical challenges in HPRO surgery.

A novel 3D hierarchical NiFe-LDH/graphitic porous carbon composite as multifunctional adsorbent for efficient removal of cationic/anionic dyes and heavy metal ions

Developing effective adsorbents for wastewater purification is crucial, as excessive emissions of toxic dyes and heavy metal ions have been proven harmful to ecosystems and human health. A NiFe-layered double hydroxide/graphitic porous carbon (NiFe-LDH/GPC) composite was fabricated by introducing NiFe-LDH nanosheets into GPC via a simple hydrothermal method to utilize the advantages of both materials fully, and thus ultimately obtain a composite adsorbent with improved adsorption properties. The samples obtained were comprehensively characterized by various characterization means, and the effects of several critical influential factors on the pollutant uptake capability of the NiFe-LDH/GPC were also studied through batch experiments. The results show that the as-synthesized NiFe-LDH/GPC exhibits a three-dimensional (3D) fluffy ultrathin-wall hierarchical porous structure, which possesses a high specific surface area and pore volume separately up to 506.74 m2/g and 0.22 cm3 g−1 as well as a relatively narrow pore size distribution. These characteristics bring advantages to enhance the adsorption ability of the NiFe-LDH/GPC for cationic/anionic dyes and heavy metal ions such as congo red (CR), malachite green (MG) and hexavalent chrome (Cr(VI), which reached the maximum adsorption capacity of 1726.51 mg/g, 1157.11 mg/g and 155.72 mg/g under the optimum conditions, respectively. Meanwhile, the adsorption behavior can be well described by the pseudo-second-order kinetic model and Langmuir isotherm model, reflecting that the sorption process mainly occurred chemically in the adsorbent monolayer. Furthermore, the NiFe-LDH/GPC maintained relatively high adsorption performance after multicycle testing, manifesting its good recyclability and stability.

Technologies for Mechanical Recycling of Carbon Fiber-Reinforced Polymers (CFRP) Composites: End Mill, High-Energy Ball Milling, and Ultrasonication.

Carbon fiber reinforced polymer (CFRP) composites have very high specific properties, which is why they are used in the aerospace, wind power, and sports sectors. However, the high consumption of CFRP compounds leads to a high volume of waste, and it is necessary to formulate mechanical recycling strategies for these materials at the end of their useful life. The recycling differences between cutting-end mills and high-energy ball milling (HEBM) were evaluated. HEBM recycling allowed us to obtain small recycled particles, but separating their components, carbon fiber, epoxy resin, and CFRP particles, was impossible. In the case of mill recycling, these were obtained directly from cutting a CFRP composite laminate. The recycled materials resulted in a combination of long fibers and micrometric particles-a sieving step allowed for more homogeneous residues. Although long, individual carbon fibers can pass through the sieve. Ultrasonication did not significantly affect HEBM recyclates because of the high energy they are subjected to during the grinding process, but it was influential on end mill recyclates. The ultrasonication amplitude notably impacted the separation of the epoxy resin from the carbon fiber. The end mill and HEBM waste production process promote the presence of trapped air and electrostatics, which allows recyclates to float in water and be hydrophobic.

P122. Creating sustainability in centers performing high volume adult spinal deformity surgery: evaluation of the Maryland all-payer model

P122. Creating sustainability in centers performing high volume adult spinal deformity surgery: evaluation of the Maryland all-payer model

Improving market (cull) dairy cows carcass traits and meat quality

Despite a high volume of market (cull) dairy cows entering the food chain every year, beef from market dairy cows is largely considered insignificant when compared with beef from beef cattle in the market and is widely thought to be used for ground beef only. Our study aimed to evaluate the effects of feeding dairy market cows on a lactating TMR diet before slaughter on carcass and beef quality traits. Forty-three Holstein market cows were randomly assigned into 2 treatments: Fed or Direct. Fed cows (n = 22) were dried off, then fed a lactating cow TMR ration for approximately 60 d whereas Direct cows (n = 21) were sent directly to slaughter. Hot carcass weight (HCW) was used to calculate the dressing percentage (DP) together with the animals' body weight recorded when animals left the farm to go to the abattoir. At 24h post-mortem, the rib fat thickness (RFT) and rib eye area (REA) were measured by a certified grader. Afterward, rib samples were collected between the 12th -10th ribs from one side of the carcass and divided into 5 ribeye steaks. The first steak was used for intramuscular fat (IMF) content analysis by NIRS. The other 4 steaks were then aged for 7, 14, 21, or 28 d. Following aging, the steaks available were assessed for tenderness using the Warner-Bratzler Shear Force protocol. Data were analyzed by mixed linear regression to compare experimental groups for continuous outcomes. HCW of the Fed cows was higher than the Direct cows, with a mean HCW of 408.3 kg and 326.1 kg, respectively (SE ± 9.0). Average DP in Fed cows was 49.1%, compared with 42.5% in Direct cows (SE ± 0.69). The average percentage of IMF in Fed cows was 8.1% and in Direct cows was 5.0% (SE ± 0.43). Fed cows had a mean REA of 68.1 cm2 and Direct cows had a mean of 57.7 cm2 (SE ± 11.9). No differences were found for RFT. The steaks aged for 14 d resulted in meat with a mean shear force (SF) of 4.19 kg in Fed cows, while Direct cows had a mean SF of 6.28 kg (SE ± 0.29) Feeding market dairy cows for 60 d before slaughter enhanced carcass weight and yield, IMF content, and tenderness. These results indicate that approximately 60 d of feeding can improve the quality of market dairy cow meat and may help improve market cow value.

Electrospray ionisation suppression in aquatic dissolved organic matter studies – Investigation via liquid chromatography–mass spectrometry

Ionisation suppression is a persistent issue in electrospray ionisation mass spectrometry, which decreases the signal of co-eluting analytes. In non-targeted analysis, where analyte and organic matrix identity is unknown, this poses a very challenging analytical problem when it comes to quantitatively assessing differences between samples, including in a compositional sense. In this study, I demonstrate the problems that arise due to ionisation suppression using a very simple sample mixing scheme between a fresh, metabolite rich sample (a leaf leachate) and a forest pond water. Samples were analysed after solid phase extraction on Agilent PPL and using high performance liquid chromatography coupled to electrospray ionisation – Orbitrap mass spectrometry, charged aerosol detector and diode array detector, the latter two allowing quantification of eluting material. I found that more than half of the well-resolved analytes expected to be present (at equal concentration) were completely lost from detection after mixing with pond water DOM. The average recovery of analytical signal (i.e., the signal weighted average), was about 50%, and was highly variable between analytes. Ionisation suppression also affected the signal obtained from the geochemical background DOM, and material recovery decreased slightly when mixing samples and extracting at a higher volume on PPL. Overall, the results showed that ionisation suppression is an extremely important problem for comparison of biogeochemical samples, even when only considering presence and absence of detected features. A multi detector approach and liquid chromatographic separation adds great value in comparison to use of only high resolution mass spectrometry (in direct infusion mode).

The Utilization of Rice Husk as Both the Silicon Source and Mesoporous Template for the Green Preparation of Mesoporous TiO2/SiO2 and Its Excellent Catalytic Performance in Oxidative Desulfurization.

In recent years, TiO2-based catalysts have received extensive attention from researchers for their excellent oxidative desulfurization (ODS) performances. In this paper, a series of mesoporous TiO2/SiO2 catalysts with different TiO2 loadings are prepared, using an incipient wetness impregnation method with agricultural waste rice husk as both the silicon source and mesoporous template and tetrabutyl titanate as the titanium source. The effect of different TiO2 loadings on the ODS performance of the samples is investigated, and the appropriate TiO2 loading is 2.5%. Compared with pure TiO2, the 2.5%TiO2/SiO2 sample exhibits high catalytic activity for oxidative desulfurization. This is, on the one hand, due to the high specific surface area and mesopore volume of the 2.5%TiO2/SiO2 sample. On the other hand, it is due to the uniform dispersion of TiO2 grains with an average diameter of 6.1 nm on the surface of the mesoporous SiO2 carrier, which greatly increases the active sites of the 2.5%TiO2/SiO2 sample, thus improving the catalytic activity of the sample. The recycling performances of the 2.5%TiO2/SiO2 sample are further investigated. The results show that, after fifteen cycles, the 2.5%TiO2/SiO2 sample still maintains high conversions of dibenzothiophene (99.8%) and 4,6-dimethyldibenzothiophene (99.7%) without deactivation. In addition, the 2.5%TiO2/SiO2 sample treated with TBHP aqueous solution is characterized by the technique of UV-Vis, and the Ti-peroxo (Ti-OOtBu) species, the active intermediate for the ODS of bulky organic sulfides, is successfully captured. Finally, a possible reaction mechanism for the ODS process over the 2.5%TiO2/SiO2 sample is proposed.

Evaluation of operational parameters and technology readiness for enhanced management of oilfield produced water treated by ozonation

Managing oilfield produced water (OPW) is a significant challenge for the petrochemical industry due to the high daily volumes generated and strict disposal limits for oil and grease (O&G) content. O&G levels are influenced by organic compounds known as naphthenic acids (NAs). This study explored ozonation to degrade cyclohexane carboxylic acid (CHCA, a model compound for NAs) present in a synthetic OPW matrix and reduce O&G in real OPW from offshore platforms. Experiments were conducted on four ozonation prototypes with varying effluent capacities: a simplified bench-scale prototype (200 mL), an extended bench-scale prototype (400 mL to 800 mL), a hydrodynamic cavitation reactor with Venturi (5 L), and a pilot unit reactor (25 L to 80 L). CHCA degradation ranged from 91 % to 100 % under optimized conditions for each prototype. Additionally, the ozonation treatment met the Brazilian National Environment Council’s disposal requirements for OPW in oceanic regions, achieving an O&G content below 29 mg/L within 30 min at natural pH. The energy required for degradation (ERC) decreased from 729.2 kWh/m3 to 30.3 kWh/m3 as ozonation scaled up from the simplified bench-scale system (200 mL) to the pilot scale (80 L). For real OPW, the ERC was even lower at 34.5 kWh/m3. These findings demonstrate the effectiveness of ozonation in treating OPW and underscore the importance of multi-scale studies to evaluate the technical and economic viability of this treatment technology. This contributes to the sustainable management of industrial waste even in space-restricted installations such as offshore oil production facilities.

Study of the effect of void defects on the mechanical properties of fiber reinforced composites

This study is to investigate the mechanical properties of fiber-reinforced polymer (FRP) composites considering void defects by adopting a representative volume element model. The results reveal that initial damage always sprouts at the interface, the void defects affect the location of the initial damage and are the dominant factor in determining the stress required for damage sprouting. In addition, the void defects as well as the neighboring debonding interfaces together determine the direction of the main damage evolution zone. The transverse tensile properties are most affected by the void defects, while the longitudinal tensile properties are least affected. In particular, the strength is more sensitive to void defects than that of elastic constants. In addition, the mechanical properties of high Fiber Volume Fraction (FVF) FRP composites are significantly stronger affected by void defects than those of low FVF FRP composites.

Bottle test technique for separating water-in-sunflower oil emulsion under an application of electric field stabilised by surfactant and hydrolysed polyacrylamide

The efficacy of separating water-in-oil emulsions depends on the stability of the emulsion, which is influenced by the interaction of the polymer and surfactant at the oil–water interface. We examined the role of hydrolysed polyacrylamide and surfactants on the stability of water-in-oil emulsions. The effects were investigated by implementing bottle tests (BT) and electrocoalescence bottle tests (EBT) using various types of surfactants over a wide range of concentrations. For a high volume fraction (10% v/v) of emulsion, the BT study showed 80% of separation in a short duration. At a small volume fraction (2% v/v), efficient separation was achieved by applying an electric field. These studies were further extended to a hybrid mode of operation, combining 1 kV/cm, non-uniform DC electrical fields at a temperature of 60 °C, to achieve maximum separation efficiency of up to 91% within 10 min for deionised water when the volume fraction of water in the emulsion was 2%. Under the same conditions, we observed an impressive 88% separation for surfactant and polymer-stabilised emulsions. HPAM does not affect interfacial tension due to its lack of amphiphilic character. However, it significantly increases the viscosity of the dispersed phase by forming a network that restricts coalescence, thereby affecting the separation rate. Surfactants enhance stability by reducing interfacial tension (IFT) and forming a protective layer around the droplet. The findings provide valuable insights for optimising separation processes using the synergy of the heating and electric fields. The study successfully and efficiently separates oil and water, even when dealing with challenging emulsions containing polymers and surfactants, by combining heating and electrical methods.

Improvement of strength and microstructure of low-carbon cementitious materials with high volume of calcined coal gangue

The accumulation of coal gangue poses significant environmental challenges due to its massive volume and low reactivity. This study investigates the influence of calcium hydroxide (Ca(OH)₂) and gypsum on the mechanical properties, hydration, and pore structure of low-carbon cementitious materials incorporating high volumes of calcined coal gangue (CCG) and limestone. The results showed that the addition of Ca(OH)₂ significantly increased compressive strength, with a 19 % improvement at 28 days in LCC-40-P mix, which contained 40 % cement and 2.73 % Ca(OH)₂ by weight. The incorporation of 10 % gypsum in the LCC-40-P mix and 20 % gypsum in the LCC-70 mix (containing 70 % cement without Ca(OH)₂) effectively refined the pore structure, reduced overall porosity, and enhanced the material's density and mechanical properties, resulting in compressive strengths of 38.4 MPa (72 % of the strength of Portland cement) and 50.2 MPa (94 % of the strength of Portland cement) at 28 days, respectively. Microstructure and hydration heat tests showed that the addition of Ca(OH)₂ accelerates the hydration reaction and significantly enhanced compressive strength by ensuring sufficient Ca(OH)₂ for pozzolanic reactions, leading to the formation of additional calcium silicate hydrate, calcium aluminate silicate hydrate and carboaluminate phases. Gypsum refined the pore structure by shifting the pore size distribution towards smaller sizes, reducing overall porosity, and increasing the proportion of gel and small capillary pores. These findings highlight the potential of using CCG with optimized additives to develop sustainable, low-carbon construction materials with enhanced performance characteristics.

Direct aging treatment of TiN modified Al–Mn–Sc alloy processed by laser powder bed fusion: On the microstructure evolution and mechanical property enhancement

In this study, the TiN nanoparticles modified Al–Mn-Sc composite and Al–Mn-Sc alloy have been fabricated by the laser powder bed fusion (LPBF). The microstructure, mechanical properties and strengthening mechanisms of these materials were discussed in details for both the as-built and artificial aged conditions. The results showed that the aged Al–Mn-Sc/TiN composite exhibits homogeneous nucleation with equiaxed grains ranging from 0.81 μm to 1.30 μm. After direct aging treatment of 300 °C, there are a volume fraction of secondary L12-Al3(Ti, Sc, Zr) nanoparticles precipitated in the composite sample, contributing to an ultra-high fracture strength of 701 ± 16 MPa. The increment in strength brought by TiN mainly comes from fine grains and high volume fraction of L12-Al3(Ti, Sc, Zr) nanoprecipitates. The fracture behaviors suggest that the uniform distribution of reinforced particles and less amount of micro pores can improve the strength and ductility of LPBF particle reinforced aluminum matrix composites.

The Impact of Surgeon Volume on Unicompartmental Knee Arthroplasty Survivorship: A Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI) Database Analysis

BackgroundThe utilization of unicompartmental knee arthroplasty (UKA) has remained low when compared to total knee arthroplasty (TKA), possibly due to higher rates of revision and reoperation. This study aimed to quantify surgeon UKA case-volumes and measure the effect of surgeon volume on early revision. We hypothesized that surgeons who have high case volumes would have lower revision rates compared to medium- and low-volume surgeons. MethodsPrimary UKAs were performed between February 2012 and November 2021, and associated revisions were identified utilizing the Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI). Surgeon information, including total cases and annual UKA volume, was collected. Case volume per year was stratified as High (≥ 35 cases per year), Medium (15 to 34 cases per year), and low (< 15 cases per year). ResultsThere were a total of 15,542 UKAs performed. Of these, 701 (4.5%) were revised, and 412 (58.8%) revisions occurred within 2 years. Of the 287 surgeons who performed an UKA in the registry, 237 (82.6%) were low-volume surgeons, 36 (12.5%) were medium-volume, and 14 (4.9%) were high-volume. High-volume surgeons were more likely to operate on older patients (P < 0.01), Medicare patients (P < 0.01), and patients who had ASA (American Society of Anesthesiologists) scores of III and IV (P < 0.01). High-volume surgeons had significantly lower 5-year revision rates compared to medium and low-volume surgeons (high: 4.3% (95% CI [confidence interval]: 3.70 to 4.90), medium: 5.2% (4.44 to 6.12), low: 7.2% (6.37 to 8.02); P < 0.001). In comparison, the 5-year revision rate for TKA in Michigan was 3.0% (95% CI: 2.90 to 3.08). ConclusionWhen UKAs were performed by high-volume surgeons in the state of Michigan, there was better survivorship when compared to low-volume and medium-volume surgeons. High-volume surgeons were more likely to perform UKA on older patients, Medicare patients, and patients who had ASA scores of III and IV. The revision rate for the high-volume surgeons still exceeded the 5-year revision rate for total knee arthroplasty in Michigan.

Drivers of long-term changes in summer compound hot extremes in China: Climate change, urbanization, and vegetation greening

Induced by numerous environmental and anthropogenic factors, the frequency of compound hot extremes (CoHot) is increasing globally. However, there is a lack of a comprehensive understanding of the relative importance of different factors in the change of CoHot, as most studies focused solely on individual factors. We systematically attribute the long-term trends of summertime CoHot in China to 24 factors including climate background, climate change, urbanization (including impervious area expansion and three-dimensional urban morphology), and vegetation change, using partial least square regression (PLSR) and variable importance projections for analysis. Cross-evaluation results based on 2259 meteorological stations indicate that the PLSR model accurately simulates the trends of CoHot frequency, duration, and intensity, with a relative error of 4–20% from national to individual station scales. A warm and humid climate background, rising average summertime temperatures, impervious area expansions, high building volume densities, low building heights, and vegetation wilting are the main factors that favoring the increasing and intensifying trends of CoHot. Although summertime warming contributes the most, the significance of urbanization and vegetation greening has been growing in recent years. Urbanization's contribution increases from 9.3% on a national scale to over 40% in urban centers, mainly due to increased building volume density rather than expansions of impervious area. In northern China, vegetation greening has reduced the local increasing trends in frequency/duration of CoHot by 20% to 40%, and such mitigation effects are primarily induced by increased vegetation cover. Our results suggest that, reducing building volume density and promoting vegetation greening can mitigate the increasing risk of CoHot under global warming.

Highly microporous activated carbons synthesized from sacrificial templating of melamine for CH4 and H2 storages and CH4/H2 adsorptive separation

Achieving carbon neutrality necessitates advancements in adsorbent-based gas storage technologies, particularly for maximizing the utilization of natural gas (CH4) and hydrogen (H2) as sustainable energy sources. Activated carbons, characterized by their high surface area, stability, and cost-effectiveness, emerge as promising candidates for CH4 and H2 storage applications. Here, we report highly microporous activated carbons prepared using sacrificial templating of melamine followed by Cs+ ion activation. The resulting activated carbon demonstrates exceptional microporous characteristics, boasting a significantly high micropore surface area (2311 m2/g) and micropore volume (1.070 cm3 g−1). These structural attributes translate into impressive CH4 (11.92 mmol/g at 298 K and 70 bar) and H2 (2.74 mmol/g at 298 K and 70 bar) storage capacities, underscoring its potential as a viable ambient temperature gas storage material. Furthermore, our evaluation extends to the performance of the activated carbon for adsorptive CH4/H2 separation. The activated carbon exhibits a notable CH4 working capacity (3.13 mmol/g at 298 K, 1–10 bar pressure swing) coupled with a moderate Ideal Adsorbed Solution Theory (IAST) selectivity (25). These findings highlight the suitability of the activated carbon for both CH4 and H2 storage applications, as well as the separation of H2 from CH4.

The Additive to Mass Manufacturing Process of Mixed Potential Electrochemical Sensors

Additive manufacturing allows for quick turn around and low cost of production of small numbers of parts. These attributes lend the technology to prototype development, where design changes are many and production numbers are low [1]. Once design parameters have been nailed down, additive manufacturing’s low throughput and poor reproducibility limit application to high volume production.Here, we discuss the implementation of direct-write extrusion of ceramic pastes and metal inks for prototype manufacturing of mixed potential electrochemical sensors and the transition to tape casting and screen printing for high volume production. Throughout the prototyping phase, direct write extrusion enabled quick and easy production of low numbers of parts, enabling various changes in sensor design and material to improve sensor performance. Sensor design evolved from a disk shape (Fig. 1 a) to a stick with integrated heater (Fig. 1 b, c). Direct write extrusion of substrate enabled quick testing of various stabilized zirconia ceramics to improve the sensitivity of the device [2]. Limitations of additive manufacturing became apparent when attempting to integrate the heater into the device, the inconsistent linewidths led to areas of high resistance and hot spots (Fig. 1 c). Tape-casting and screen printing of the devices was adopted for three reasons, first, to improve line fidelity, which is vitally important when printing small electrodes as well as heater traces (Fig. 1 d), second, to further decrease conductivity of substrate by laminating multiple layers of different ceramic materials, and finally to increase manufacturing throughput (Fig. 1 d, e).This work was supported by US Department of Energy Award DE-FE0031864References[1] T. D. Ngo, A. Kashani, G. Imbalzano, K. T. Q. Nguyen, and D. Hui, “Additive manufacturing (3D printing): A review of materials, methods, applications and challenges,” Compos. Part B Eng., vol. 143, pp. 172–196, Jun. 2018, doi: 10.1016/j.compositesb.2018.02.012.[2] S. Halley, K. Ramaiyan, F. Garzon, and L. Tsui, “Massive enhancement in sensitivity of mixed potential sensors towards methane and natural gas through magnesia stabilized zirconia low ionic conductivity substrate,” Sens. Actuators B Chem., vol. 392, p. 134031, Oct. 2023, doi: 10.1016/j.snb.2023.134031. Figure 1

(Invited) Department of Energy, Energy Efficiency and Renewable Energy - Activity Updates in Reversible Fuel Cells and High Temperature Electrolysis

The Hydrogen and Fuel Cell Technologies Office (HFTO) within the U.S. Department of Energy’s (DOE) Office of Energy Efficiency and Renewable Energy (EERE) supports a range of analysis, research, development, and demonstration efforts that fall under the areas of high temperature electrolysis (HTE) and reversible fuel cells (RFCs). These efforts range from earlier stage R&D on cell components to demonstrating early system technology. Particularly when used in conjunction with high temperature process heat, HTE technology shows promise for highly efficient, cost effective, sustainable hydrogen production at high volumes. This potential has led to its inclusion in multiple HFTO initiatives, including two national lab-led consortia separately focused on next generation materials and overcoming technical barriers to manufacturing durable, affordable, and efficient HTE systems. These consortia objectives, efforts, scopes, and developments are discussed in the context of HTE and recent DOE initiatives and announcements, including the Hydrogen Energy Earthshot, Long Duration Energy Storage Earthshot, and Clean Fuels and Products Earthshot.