Low Load Research Articles

Highly Active Oxidation Catalysts through Confining Pd Clusters on CeO2 Nano‐Islands

AbstractCeO2‐supported noble metal clusters are attractive catalytic materials for several applications. However, their atomic dispersion under oxidizing reaction conditions often leads to catalyst deactivation. In this study, the noble metal cluster formation threshold is rationally adjusted by using a mixed CeO2‐Al2O3 support. The preferential location of Pd on CeO2 islands leads to a high local surface noble metal concentration and promotes the in situ formation of small Pd clusters at a rather low noble metal loading (0.5 wt %), which are shown to be the active species for CO conversion at low temperatures. As elucidated by complementary in situ/operando techniques, the spatial separation of CeO2 islands on Al2O3 confines the mobility of Pd, preventing the full redispersion or the formation of larger noble metal particles and maintaining a high CO oxidation activity at low temperatures. In a broader perspective, this approach to more efficiently use the noble metal can be transferred to further systems and reactions in heterogeneous catalysis.

Modeling the Structure of Ketoprofen-Poly(vinylpyrrolidone) Amorphous Solid Dispersions with Empirical Potential Structure Refinements of X-ray Scattering Data.

The metastability of amorphous formulations poses barriers to their safe and widespread commercialization. The propensity of amorphous solid dispersions (ASDs) to crystallize is directly linked to their molecular structure. Amorphous structures are inherently complex and thus difficult to fully characterize by experiments, which makes structural simulations an attractive route for investigating which structural characteristics correlate with ASD stability. In this study, we use empirical potential structure refinement (EPSR) to create molecular models of ketoprofen-poly(vinylpyrrolidone) (KTP/PVP) ASDs with 0-75 wt % drug loading. The EPSR technique uses X-ray total scattering measurements as constraints, yielding models that are consistent with the X-ray data. We perform several simulations to assess the sensitivity of the EPSR approach to input parameters such as intramolecular bond rotations, PVP molecule length, and PVP tacticity. Even at low drug loading (25 wt %), ∼40% of KTP molecules participate in KTP-KTP hydrogen bonding. The extent of KTP-PVP hydrogen bonding does not decrease significantly at higher drug loadings. However, the models' relative uncertainties are too large to conclude whether ASDs' lower stabilities at high drug loadings are due to changes in drug-excipient hydrogen bonding or a decrease in steric hindrance of KTP molecules. This study illustrates how EPSR, combined with total scattering measurements, can be a powerful tool for investigating structural characteristics in amorphous formulations and developing ASDs with improved stability.

Hierarchical Silica Composites for Enhanced Water Adsorption at Low Humidity.

To combat water scarcity in remote areas around the world, adsorption-based atmospheric water harvesting (AWH) has been proposed as a technology that can be used alongside existing water production capabilities. However, commonly used adsorbents either have low water adsorption loadings or are difficult to regenerate. In this work, we developed two novel hierarchical silica-salt composites that both exhibit high water adsorption loadings under dry and humid conditions. The total water vapor loading, kinetics, and heats of water adsorption for both silica-salt composites were investigated. As hierarchical silicas have tunable pores and large pore volumes, these materials serve as effective host matrixes for the hygroscopic salt LiCl. Our results suggest that hierarchical pores play a significant role in water adsorption: micropores and some smaller mesopores act as "storage" sites for hygroscopic salt, whereas larger mesopores and macropores increase the accessibility of water vapor into the silica. Using this mix of pores, we achieved greater than 0.4 g H2O/g composite at 10% RH and 27 °C. Additionally, we found that the salt-impregnated silica and bare silica had the same heat of adsorption: 80-90 kJ/mol. The results suggest that the H-bond interactions are similar for both systems and that the primary mechanism at play here is water cluster adsorption/desorption. Despite the similar energies, the LiCl-containing materials exhibited considerably slower kinetics than bare silica materials. Of equal importance to the adsorption capacity and kinetics of these composites is their mechanical stability. To assess their mechanical stability, high-energy ball milling of silica was conducted to create more uniform particle sizes. However, reduced particle sizes came at a cost─the BET surface areas and pore volumes were drastically decreased after more than 1 h of ball milling. Findings from this study suggest that short-term ball milling may be a viable large-scale option to reduce particle size in silica materials without sacrificing significant performance.

Elucidating the role of organic loading rate on the performance and microbial dynamics of a novel continuous-flow aerobic granular sludge reactor

Aerobic granular sludge technology operated in continuous-flow reactors enables the upgrading of existing conventional wastewater treatment plants. The viability of applying this technology at full-scale increases with the simplicity of the bioreactor design. Hence, in contrast to previous research carried out in complex configurations, this study is based on evaluating the capacity of a novel single-chamber continuous-flow bioreactor to operate at different loads found in domestic sewage, highlighting that this configuration combines and joins the advantages of activated sludge and granular sludge technologies. At organic loading rates ranging from 0.45 to 1.85 kg COD•m−3•d−1, the reactors achieved high performance, removing >80 % of the chemical oxygen demand, regardless influent characteristics. The trend of ammonium removal rates was risen over operational time. Moreover, the granular size and biomass concentration increased with the organic loading rate. Changes in the influent did not compromise the structure of the granules. Microbiota studies showed a high diversity in communities at lower organic loading rates, whereas a strong microbial competition was detected at high loading rates, linking with lower evenness. Phylotypes belonging to Hypocreales played a key role in mature granules.

Reciprocating wear behavior of multi-directionally forged and aged Al-Cu-Li alloy

Abstract Al-Cu-Li alloys have drawn attention because of their decreased density, which is a result of the growing need for lightweight material systems in aerospace and aircraft applications. The Al-Cu-Li alloy, which has potential usage in aerospace and aviation structural components, is the subject of this study. The alloy was subjected to multi-directional forging (MDF) and post-MDF artificial aging. Reciprocating sliding wear tests were conducted to investigate the effects of these processes on wear properties under different load conditions. After MDF, a decrease in wear resistance was noticed, on the other hand, 12 pass MDF treated samples showed improved wear resistance upon aging treatment. Wear scars and counter ball surfaces were examined using scanning electron microscope (SEM) in order to understand the wear processes. The findings demonstrated that, at lower loads, adhesion and abrasion were the main wear processes; at greater loads, delamination, adhesion, and abrasion were clearly visible. Our study revealed that the MDF and its aging after processing have a substantial effect on the wear behavior of Al-Cu-Li alloy. This discovery has important implications for the development of lightweight materials that could be used in aerospace and aircraft applications.

Rational design of membrane electrode assembly for anion exchange membrane water electrolysis systems

Anion exchange membrane water electrolysis (AEMWE) is a promising and potentially low-cost technology for producing green hydrogen, but a novel manufacturing technique with rational design of the electrodes is essential to improve the performance and stability. In this work, we investigate the effect of electrode structure on activity and the stability of AEMWEs by fabricating membrane electrode assemblies (MEAs). For the first time, the decal transfer method with platinum-group-metal-free (PGM-free) catalyst was successfully used in AEMWEs. With this method, deposition of a compact catalyst layer (CL) on the membrane was achieved without damaging neither the CL nor the membrane. The MEAs were designed for AEMWE using 1 M KOH as the electrolyte and the ionomer content was optimized for both cathode and anode. In the anode, a low ionomer loading improved activity and ionic conductivity, however, a higher ionomer content was beneficial for the cathode. Furthermore, the type of ionomer on the anode side has shown to be the major reason of loss of performance over time. An ionomer with low (1.4–1.7 meq g−1) Ion Exchange Capacity (IEC) and Nafion™ ionomer greatly improved the stability.

Blood Flow Restriction Exercise as a Novel Conservative Standard in Patients with Knee Osteoarthritis—A Narrative Review

Knee osteoarthritis is a prevalent joint disease affecting millions of individuals globally. While total knee arthroplasty is an effective treatment for advanced stages of KOA, it may not be suitable for earlier stages or younger patients. Supervised exercise therapy has proven to be the first-line treatment of preference in tackling pain and disability caused by KOA. However, the high intensities required to induce positive muscle adaptations are not indicated in this population, as this is often accompanied by pain, discomfort, and frustration, leaving low-load resistance training as the only feasible method of treatment. Recently, the use of blood flow restriction training has begun to emerge as a substitute for high-load resistance training. With BFRT, a cuff is applied around the proximal aspect of the affected limb, causing partial arterial and full venous occlusion, thereby inducing localized hypoxia and the accumulation of metabolites, mimicking the effects of high-load resistance training, albeit with low loads. Consequently, BFRT might offer a suitable and more effective alternative for KOA patients who are not (yet) eligible for TKA compared to traditional exercise therapy. This review aims to summarize the current evidence as regards the application of Blood Flow Restriction in exercise therapy for knee osteoarthritis patients, with particular consideration of the underlying mechanisms and its safety, as well as general guidelines for practical implementation in clinical practice. In doing so, this narrative review aims to create a framework for translating from theory into practice.

Exploring the Combustion Performance of a Non-Road Air-Cooled Two-Cylinder Turbocharged Diesel Engine

In order to explore the combustion performance of a non-road air-cooled two-cylinder turbocharged diesel engine, an experiment on the effects of engine compression ratio, combustion chamber shape and injection timing were systematically conducted in this study. Moreover, the effects of intake air conditions on combustion performance were numerically investigated using the one-dimensional simulation platform. The findings of this study could help provide new insights for promoting the sustainable development of diesel engines used in generator sets. The results show that the increase in intake air temperature can delay the combustion center of gravity and improve the combustion performance and the sustainability of diesel engines. The decrease in intake air pressure leads to a reduction in oxygen amount during the combustion process, thus causing the deterioration of cylinder pressure and combustion performance. By modifying the combustion chamber, the ignition delay and combustion duration are each extended by 1.6 degrees and 4.2 degrees under 100% engine load. The ignition delay and combustion duration are not obviously affected by modifying the combustion chamber shape under 25% and 50% loads. By increasing the compression ratio from 19.5 to 20.5, the ignition delay and combustion duration are shortened, which could enhance the cylinder pressure and heat release rate. However, reducing the compression ratio from 19.5 to 18.5 could significantly decrease the heat release rate. Under middle and low loads, combustion duration is less affected by injection timing. Under 100% load, the peak cylinder pressure increases to 11.4 MPa, and the ignition delay is shortened by advancing injection timing from −17 °CA to −20 °CA.

Zwitterionic Poly-Carboxybetaine Polymers Restore Lubrication of Inflamed Articular Cartilage.

Osteoarthritis is a degenerative joint disease that is associated with decreased synovial fluid viscosity and increased cartilage friction. Though viscosupplements are available for decades, their clinical efficacy is limited and there is ample need for more effective joint lubricants. This study first evaluates the tribological and biochemical properties of bovine articular cartilage explants after stimulation with the inflammatory cytokine interleukin-1β. This model is then used to investigate the tribological potential of carboxybetaine (CBAA)-based zwitterionic polymers of linear and bottlebrush architecture. Due to their affinity for cartilage tissue, these polymers form a highly hydrated surface layer that decreases friction under high load in the boundary lubrication regime. For linear pCBAA, these benefits are retained over several weeks and the relaxation time of cartilage explants under compression is furthermore decreased, thereby potentially boosting the weeping lubrication mechanism. Bottlebrush bb-pCBAA shows smaller benefits under boundary lubrication but is more viscous than linear pCBAA, therefore providing better lubrication under low load in the fluid-film regime and enabling a longer residence time to bind to the cartilage surface. Showing how CBAA-based polymers restore the lost lubrication mechanisms during inflammation can inspire the next steps toward more effective joint lubricants in the future.

Probabilistic assessment of short‐term voltage stability under load and wind uncertainty

AbstractContemporary electricity networks are exposed to operational uncertainties, which may jeopardise the stability of the power grid. More specifically, the increasing penetration level of variable renewable energy generation and uncertainty in load demand are key catalysts for these emerging stability issues. A mathematical relationship is established to track the system voltage trajectory with respect to variations in uncertain inputs (associated with wind speed, system load, and wind power penetration levels). Additionally, it demonstrates the consequences of varying uncertain inputs on the short‐term voltage response across different potential operating conditions. The theoretical proposition has further been verified by the simulation studies with two test power networks in DIgSILENT PowerFactory software. The simulation results revealed that uncertain injection sources significantly impacted the system voltage at the receiving end. High uncertainty in wind speed and system loads increased voltage recovery variation, causing delays in voltage response during low wind speeds and high system loads. Additionally, increased wind power penetration levels expanded voltage recovery uncertainties, resulting in decreased system voltage and potentially leading to voltage violations and instability at 30% wind power levels. Moreover, the results showed that the system's response time increased, and in some cases, it collapsed due to increased system capacity (>80%) and dynamic load (>75%), as well as encountering a large disturbance under uncertain circumstances.

Spatially Confined Assembly and Immobilization of Hierarchical Nanoparticle Architectures inside Microdroplets in Magnetic Fields.

Magnetic field-directed colloidal interactions offer facile tools for assembly of structures that range from linear chains to multidimensional hierarchical architectures. While the field-driven assembly of colloidal particles has commonly been investigated in unbounded media, a knowledge gap remains concerning such assembly in confined microenvironments. Here, we investigate how confinement of ferromagnetic nanoparticles in microspheres directs their magnetic assembly into hierarchical architectures. Microdroplets from polydimethylsiloxane (PDMS) liquid precursor containing dispersed iron oxide magnetic nanoparticles (MNPs) were placed in a static magnetic field leading to the formation of organized assemblies inside the host droplets. By changing the MNP concentrations, we revealed a sequence of microstructures inside the droplets, ranging from linear chains at a low MNP loading, transitioning to a combination of chains and networked bundles, to solely 3D bundles at high MNP loading. These experimental results were analyzed with the aid of COMSOL simulations where we calculated the potential energy to identify the preferred assembly conformations. The chains at high MNP loading minimized their energy by aggregating laterally to form bundles with their MNP dipoles being out-of-registry. We cured these PDMS droplets to immobilize the assemblies by forming soft microbeads. These microbeads constitute an "interaction toolbox" with different magnetic macroscale responses, which are governed by the structuring of the MNPs and their magnetic polarizability. We show that thanks to their ability to rotate by field-induced torque under a rotating field, these microbeads can be employed in applications such as optical modulators and microrollers.

The impact of tertiary lymphoid structures on tumor prognosis and the immune microenvironment in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is a common malignancy whose prognosis and treatment outcome are influenced by many factors. Some studies have found that tertiary lymphoid structures (TLSs) in cancer may contribute to prognosis and the prediction of immunotherapy efficacy However, the combined role of TLSs in NSCLC remains unclear. We accessed The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases to obtain mRNA sequencing data and clinical information as the TCGA cohort, and used our own sample of 53 advanced NSCLC as a study cohort. The samples were divided into TLS+ and TLS- groups by pathological tissue sections. Patients of the TLS+ group had a better OS (p = 0.022), PFS (p = 0.042), and DSS (p = 0.004) in the TCGA cohort, and the results were confirmed by the study cohort (PFS, p = 0.012). Furthermore, our result showed that the count and size of TLSs are closely associated with the efficacy of immunotherapy. In addition, the TLS+ group was associated with better immune status and lower tumor mutation load. In the tumor microenvironment (TME), the expression levels of CD4+ T cells and CD8+ T cells of different phenotypes were associated with TLSs. Overall, TLSs are a strong predictor of survival and immunotherapeutic efficacy in advanced NSCLC, and T cell-rich TLSs suggest a more ordered and active immune response site, which aids in the decision-making and application of immunotherapy in the clinic.

Comparative Analysis of Viral Load and Cytokines during SARS-CoV-2 Infection between Pregnant and Non-Pregnant Women

To better understand the vulnerabilities of pregnant women during the COVID-19 pandemic, we conducted a comprehensive, retrospective cohort study to assess differences in immune responses to SARS-CoV-2 infection between pregnant and non-pregnant women. Nasopharyngeal swabs and serum specimens from 90 pregnant and 278 age-matched non-pregnant women were collected from 15 March 2020 to 23 July 2021 at NewYork-Presbyterian Queens Hospital in New York City. Multiplex reverse transcription polymerase chain reaction, neutralizing antibody, and cytokine array assays were used to assess the incidence, viral load, antibody titers and profiles, and examine cytokine expression patterns. Our results show a lower incidence of SARS-CoV-2 infection in pregnant women compared with non-pregnant women. Pregnant women infected with SARS-CoV-2 exhibited a substantially lower viral load. In addition, the levels of both anti-spike protein receptor-binding domain IgG neutralizing antibodies and anti-N Protein IgG were elevated in pregnant women. Finally, cytokine profiling revealed differential expression of leptin across cohorts. These findings suggest that pregnancy is associated with distinct immune and virological responses to SARS-CoV-2 infection, characterized by lower infection rates, substantially lower viral loads, and enhanced antibody production. Differential cytokine expression indicates unique immune modulation in pregnant women.

Predicting Blast-Induced Damage and Dynamic Response of Drill-and-Blast Tunnel Using Three-Dimensional Finite Element Analysis

The significance of predicting the dynamic response and damage of an existing concrete tunnel during underground blasting has increased owing to the close proximity between the newly built and existing tunnels. Peak particle velocity (PPV) is a commonly used criterion in the assessment of blast-induced structural damage. However, such structural damage is also associated with the frequency content of the blast wave. Nevertheless, the recommended threshold PPVs, which are based on empirical criteria, predict conservative estimations. Using stringent and regulated blasting methods often results in project delays and escalates the total project expenditure. In this paper, a three-dimensional finite element model of an underground tunnel has been developed in LS-DYNA to analyze damage to the concrete tunnels under blast loading. A suite of analyses was performed to examine the potential damage induced in the underground tunnel. A lower frequency load was found to have a greater potential for producing damage compared with a high frequency blast load. The results showed that the location of the cracking within the tunnel, such as the arch foot or tunnel wall, was also influenced by the frequency of the blast wave. The maximum allowable PPV for the concrete tunnel was determined for a range of frequencies based on predicted free field PPV and additional factors of safety of 1.2 and 1.5 were established, depending on the safety needs and importance of the tunnel construction. Thus, our findings provide useful information for improving the evaluation of tunnel damage and guaranteeing the safety of underground tunnels.

Creep Failure Characteristics and Mathematical Modeling of High-Density Polyethylene Geomembranes under High Stress Levels

To explore the creep characteristics of geomembrane under different tensile stresses, a series of creep tests were carried out on high-density polyethylene (HDPE) geomembrane specimens. For the interpretation and fitting of the experimental data, refined approximation functions were proposed. Particular attention was paid to the creep failure behavior under high tensile stresses, i.e., 70%, 80%, and 90% of maximum peak stress. To investigate the effects of size on the mechanical response, experiments with two different membrane thicknesses were conducted. The results obtained under high stress levels were compared with creep tests at medium and low stress levels. Depending on load level, different creep characteristics can be distinguished. In the secondary creep state, the creep velocity is higher for higher load levels. In contrast to the medium and low load levels, the geomembrane under high stresses underwent the tertiary creep stage after instantaneous deformation and primary and secondary creep stages. In some tests, it was observed that under very high stress levels, creep velocity does not necessarily follow the expected trend and creep rupture can occur within a short time. For numerical simulation, an improved mathematical model was proposed to reproduce in a unified manner the experimental data of the whole non-linear evolution of creep elongation under different stress levels.

Direct Multi-Deuterium Labelling of Pirtobrutinib.

Herein, we demonstrate an efficient method for multi-deuterium labelling of pirtobrutinib-a Bruton's tyrosine kinase inhibitor recently approved by the FDA-using a straightforward hydrogen isotope exchange (HIE) reaction. A remarkably high level of deuterium incorporation was achieved using an excess of a Kerr-type iridium catalyst. The key factor in the significant deuterium labelling was the decision to employ a deuterium uniformly labelled solvent, chlorobenzene-d5, at an elevated temperature. Virtually, no d0-d3 species were detected, with only traces of d4-d5 isotopomers (< 5%) observable in the mass spectrum of pirtobrutinib-d8, fulfilling requirements for stable isotope-labelled internal standard. The labelled compound-mainly consisting of isotopomers d6-d9 at 82.4% of the total abundance-was isolated in a high yield (73%) and purity (99%). Noteworthy, fluorine group acting as a directing group was observed for the first time. Significant incorporation of deuterium in ortho-positions, exceeding 87%, was observed. Interestingly, chlorinated solvent used in the HIE reactions was non-specifically deuterated yielding up to 0.42 deuterium per chlorobenzene molecule even at an exceptionally low iridium catalyst loading of 4.17 × 10-2 mol%.

Nordalbergin Synergizes with Novel β-Lactam Antibiotics against MRSA Infection

The synergetic strategy has created tremendous advantages in drug-resistance bacterial infection treatment, whereas challenges related to novel compound discovery and identifying drug-binding targets still remain. The mechanisms of antimicrobial resistance involving β-lactamase catalysis and the degradation of β-lactam antibiotics are being revealed, with relevant therapies promising to improve the efficacy of existing major classes of antibiotics in the foreseeable future. In this study, it is demonstrated that nordalbergin, a coumarin isolated from the wood bark of Dalbergia sissoo, efficiently potentiated the activities of β-lactam antibiotics against methicillin-resistant Staphylococcus aureus (MRSA) by suppressing β-lactamase performance and improving the bacterial biofilm susceptibility to antibiotics. Nordalbergin was found to destabilize the cell membrane and promote its permeabilization. Moreover, nordalbergin efficiently improved the therapeutic efficacy of amoxicillin against MRSA pneumonia in mice, as supported by the lower bacterial load, attenuated pathological damage, and decreased inflammation level. These results demonstrate that nordalbergin might be a promising synergist of amoxicillin against MRSA infections. This study provided a new approach for developing potentiators for β-lactam antibiotics against MRSA infections.

Risk Factors for Bone Microarchitecture Impairments in Older Men with Type 2 Diabetes - The MrOS Study.

Impaired bone microarchitecture, assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT), may contribute to bone fragility in type 2 diabetes (T2DM) but data on men are lacking. To investigate the association between T2DM and HR-pQCT parameters in older men. HR-pQCT scans were acquired on 1794 participants in the Osteoporotic Fractures in Men (MrOS) study. T2DM was ascertained by self-report or medication use. Linear regression models, adjusted for age, race, BMI, limb length, clinic site, and oral corticosteroid use, were used to compare HR-pQCT parameters by diabetes status. Among 1777 men, 290 had T2DM (mean age 84.4 years). T2DM men had smaller total cross-sectional area (Tt.AR) at the distal tibia (p=0.028) and diaphyseal tibia (p=0.025), and smaller cortical area at the distal (p= 0.009) and diaphyseal tibia (p= 0.023). Trabecular indices and cortical porosity were similar between T2DM and non-T2DM. Among men with T2DM, in a model including HbA1c, diabetes duration, and insulin use, diabetes duration ≥ 10 years, compared with <10 years, was significantly associated with higher cortical porosity but with higher trabecular thickness at the distal radius. Insulin use was significantly associated with lower cortical area and thickness at the distal radius and diaphyseal tibia and lower failure load at all three scan sites. Lower cortical area, cortical thickness, total BMD, cortical BMD, and failure load of the distal sites were associated with increased risk of incident non-vertebral fracture in T2DM. Older men with T2DM have smaller bone size compared to non-T2DM, which may contribute to diabetic skeletal fragility. Longer diabetes duration was associated with higher cortical porosity and insulin use with cortical bone deficits and lower failure load.

Brain Endurance Training Improves Dynamic Calisthenic Exercise and Benefits Novel Exercise and Cognitive Performance: Evidence of Performance Enhancement and Near Transfer of Training.

Dallaway, N, Mortimer, H, Gore, A, and Ring, C. Brain endurance training improves dynamic calisthenic exercise and benefits novel exercise and cognitive performance: Evidence of performance enhancement and near transfer of training. J Strength Cond Res XX(X): 000-000, 2024-The purpose of this dual study was to evaluate whether brain endurance training (BET)-a mental fatigue countermeasure involving physical and cognitive training-enhanced exercise compared with physical training alone. Two studies (N = 29) used a pretest/training/posttest design, with participants randomized to BET or control groups. During testing, participants performed calisthenic exercises (study 1: press-ups, wall sit, and plank; study 2: burpees, jump squats, leg raises, press-ups, and plank) to failure before and after completing 20-minute cognitive tasks (study 1: memory updating; study 2: memory updating, response inhibition, and nonexecutive functions). Training comprised 3 sessions per week for 4 weeks. In study 1 training sessions, participants completed 2 submaximal exercise sets; each exercise was followed by a 3-minute cognitive task with high (BET) or low (control) cognitive loads. In study 2 training sessions, participants completed 1 submaximal exercise set; after 12-minute cognitive tasks (BET) or rest (control), each exercise was preceded by a 3-minute cognitive task (BET) or rest (control). These cognitive tasks involved response inhibition and memory updating. Performance (exercise repetitions/duration), perceived exertion, and mental fatigue were assessed. In pretesting, exercise performance was matched between groups. In posttesting, BET groups performed more dynamic exercises than control groups but the same number of static exercises. Cognitive task performance was either greater for BET or not different between groups. Neither perceived exertion nor mental fatigue differed between groups and tests. Brain endurance training enhanced dynamic but not static calisthenic exercise performance compared with physical training alongside near transfer of training benefits for novel physical and cognitive task performance.

Ammonia energy fraction effect on the combustion and reduced NOX emission of ammonia/diesel dual fuel

With stringent regulations of internal combustion engine on reducing CO2 emission, ammonia has been used as an alternative fuel. Investigating how engine-related performance is affected by partial ammonia replacement of diesel fuel is essential for understanding the combustion. Therefore, in this study, a three-dimensional numerical simulation model is developed for the burning of two fuels of diesel and ammonia based on relevant parameters (i.e., compression ratio, load, ammonia energy fraction, etc.) in a lab-made diesel engine. The consequences of load and compression proportion on combustion and pollutant emissions are investigated for ammonia energy fractions between 50% and 90%. When the ammonia portion rises, the increased ammonia equivalent ratio causes ammonia to move away from the dilute combustion boundary and accelerates the combustion rate of ammonia. An increase in compression ratio significantly increases the specified thermal performance and combustion efficacy. When the compression ratio is 16, as the ammonia energy fractions increases, due to the increase in the proportion of ammonia, that is, the proportion of nitrogen atoms increases, more NOx is generated during the combustion process. When the ammonia substitution rate is 90%, as the compression ratio increases, the cylinder pressure and temperature increase. The combustion efficiency of ammonia increases, generating more NOx and NOx emissions can reach 0.66 mg/m3. At a compression ratio of 18, the NOx emissions can reach 1.59 mg/m3. However, under medium and low load conditions, as the ammonia fraction increases, the total energy of fuel decreases, and the combustion efficiency of ammonia decreases, resulting in a decrease in the heat released during combustion and a decrease in NOx emissions. When the ammonia substitution rate is 90% and the load is 25%, NOx emissions reach 0.1 mg/m3. This research provides theoretical suggestions for the profitable and use ammonia fuel in internal combustion engines in a clean manner.