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Differential spatial working memory–related functional network reconfiguration in young and older adults

Abstract Functional brain networks have preserved architectures in rest and task; nevertheless, previous work consistently demonstrated task-related brain functional reorganization. Efficient rest-to-task functional network reconfiguration is associated with better cognition in young adults. However, aging and cognitive load effects, as well as contributions of intra- and internetwork reconfiguration, remain unclear. We assessed age-related and load-dependent effects on global and network-specific functional reconfiguration between rest and a spatial working memory (SWM) task in young and older adults, then investigated associations between functional reconfiguration and SWM across loads and age groups. Overall, global and network-level functional reconfiguration between rest and task increased with age and load. Importantly, more efficient functional reconfiguration associated with better performance across age groups. However, older adults relied more on internetwork reconfiguration of higher cognitive and task-relevant networks. These reflect the consistent importance of efficient network updating despite recruitment of additional functional networks to offset reduction in neural resources and a change in brain functional topology in older adults. Our findings generalize the association between efficient functional reconfiguration and cognition to aging and demonstrate distinct brain functional reconfiguration patterns associated with SWM in aging, highlighting the importance of combining rest and task measures to study aging cognition.

Batch and semi-continuous treatment of cassava wastewater using microbial fuel cells and metataxonomic analysis.

The treatment of agroindustrial wastewater using microbial fuel cells (MFCs) is a technological strategy to harness its chemical energy while simultaneously purifying the water. This manuscript investigates the organic load effect as chemical oxygen demand (COD) on the production of electricity during the treatment of cassava wastewater by means of a dual-chamber microbial fuel cell in batch mode. Additionally, specific conditions were selected to evaluate the semi-continuous operational mode. The dynamics of microbial communities on the graphite anode were also investigated. The maximum power density delivered by the batch MFC (656.4μWm ) was achieved at the highest evaluated organic load (6.8 g COD L ). Similarly, the largest COD removal efficiency (61.9%) was reached at the lowest organic load (1.17 g COD L ). Cyanide degradation percentages (50-70%) were achieved across treatments. The semi-continuous operation of the MFC for 2 months revealed that the voltage across the cell is dependent on the supply or suspension of the organic load feed. The electrode polarization resistance was observed to decreases over time, possibly due to the enrichment of the anode with electrogenic microbial communities. A metataxonomic analysis revealed a significant increase in bacteria from the phylum Firmicutes, primarily of the genus Enterococcus.

Effect of axial load and shear span on seismic performance of CFT columns reinforced with end-fixed ultra-high strength rebars

Effect of axial load and shear span on seismic performance of CFT columns reinforced with end-fixed ultra-high strength rebars

Vicious Circle With Venous Hypertension, Irregular Flow, Pathological Venous Wall Remodeling, and Valve Destruction in Chronic Venous Disease: A Review.

Substantial advances occurred in phlebological practice in the last two decades. With the use of modern diagnostic equipment, the patients' venous hemodynamics can be examined in detail in everyday practice. Application of venous segments for arterial bypasses motivated studies on the effect of hemodynamic load on the venous wall. New animal models have been developed to study hemodynamic effects on the venous system. In vivo and in vitro studies revealed cellular phase transitions of venous endothelial, smooth muscle, and fibroblastic cells and changes in connective tissue composition, under hemodynamic load and at different locations of the chronically diseased venous system. This review is an attempt to integrate our knowledge from epidemiology, paleoanthropology and anthropology, clinical and experimental hemodynamic studies, histology, cell physiology, cell pathology, and molecular biology on the complex pathomechanism of this frequent disease. Our conclusion is that the disease is initiated by limited genetic adaptation of mankind not to bipedalism but to bipedalism in the unmoving standing or sitting position. In the course of the disease several pathologic vicious circles emerge, sustained venous hypertension inducing cellular phase transitions, chronic wall inflammation, apoptosis of cells, pathologic dilation, and valvular damage which, in turn, further aggravate the venous hypertension.

INFLUENCE OF PROPELLER-ICE LOADS ON THE WEAR DEVELOPMENT IN STERN TUBE BEARINGS OF MARINE PROPULSION SYSTEMS AND IDENTIFICATION OF CRITICAL OPERATING CONDITIONS

Abstract Increasing ship traffic in ice-covered waters leads to more frequent collisions between ship propellers and sea ice which causes extreme impulse loads on the propeller. Theses loads are transferred through the propeller shaft to the sliding bearings of the stern tube, especially, the aft stern tube bearings. Extreme bearing loads can lead to mixed-friction regimes which cause wear in the bearings and eventually results in a failure of the entire propulsion system. The effect of ice-induced loads on the contact conditions in the sliding bearings is widely unknown. Thus, a study of the influence of these loads on the contact conditions and wear behavior in stern tube bearings resulting from observed sea ice conditions and operating conditions of the ship is necessary. This paper aims to investigate the influence of ice collision loads on the contact conditions in the bearings of the stern tube of the research vessel SA Agulhas II. For this purpose, an elastohydrodynamic simulation and a multibody simulation based on field measurements were performed. As a result, this paper identifies the operating condition thresholds (i.e. propeller torque and rotational speed) during propeller-ice collisions that cause mixed-friction conditions in the bearings. On the basis of these conditions, a risk map is generated to assess the actual wear risk by including the frequency of occurrence of the corresponding mixed-friction condition over the duration of a voyage.

Analysis of Vibration Characteristics and Influencing Factors of Complex Tread Pattern Tires Based on Finite Element Method

The vibration of the tires significantly impacts a vehicle’s ride comfort and noise level; however, the current analysis of tire vibration characteristics often involves excessive simplification in their models, leading to a reduction in model accuracy. To analyze the tire vibrational properties and the influence of its design and service conditions, a combined modeling technology was developed to construct a three-dimensional (3D) finite element model of a 205/55R16 specification radial tire with intricate tread patterns. The accuracy and reliability of the simulation model was verified through vibration modal tests. Based on the vibration mode theory, the Lanczos method provided by ABAQUS was adopted to analyze the modal characteristics of the tire under free inflation and grounded conditions, and the effects of different inflation pressures, loads, operating conditions, and belt cord angles on the tire vibration characteristics were analyzed. The results indicate that grounding constraints will suppress the low order radial modal frequency of the tire and enhance the lateral modal frequency. The higher the order of the tire vibration mode, the greater the impact of inflation pressure. As the operating conditions change, the modal frequencies of all directions have the same trend of change, and as the ground load increases, the tire is prone to misalignment at lower lateral frequencies. The radial and lateral grounding modes of the tire are slightly affected by the change of the cord angle in the belt layer, but the circumferential grounding frequency decreases as the belt layer angle increases. These research findings offer a crucial foundation for the structural design of complex tread pattern tires, and also serve as a reference for addressing vibration and comfort issues encountered in the tire matching process.

Elucidating solvent effects on lipase-catalyzed peroxyacid synthesis through activity-based kinetics and molecular dynamics.

Peroxyacid synthesis is the first step in Prilezhaev epoxidation, which is an industrial method to form epoxides. Motivated by the development of a kinetic model as a tool for solvent selection, the effect of solvent type and acid chain length on the lipase-catalyzed peroxyacid synthesis was studied. A thermodynamic activity-based ping-pong kinetic expression was successfully applied to predict the effect of the reagent loadings in hexane. The activity-based reaction quotients provided a prediction of solvent-independent equilibrium constants. However, this strategy did not achieve satisfactory estimations of initial rates in solvents of higher polarity. The lack of compliance with some assumptions of this methodology could be confirmed through molecular dynamics calculations i.e. independent solvation energies and lack of solvent interaction with the active site. A novel approach is proposed combining the activity-based kinetic expression and the free binding energy of the solvent with the active site to predict kinetics upon solvent change. Di-isopropyl ether generated a strong interaction with the enzyme's active site, which was detrimental to kinetics. On the other hand, toluene or limonene gave moderate interaction with the active site rendering improved catalytic yield compared with less polar solvents, a finding sharpened when peroctanoic acid was produced.

Finite element analysis-based blast and seismic performance evaluation for RC frame with retrofitted ENTA damper systems

Blast loading and seismic excitations are widely recognized as the most detrimental occurrences that a building structure may encounter throughout its lifespan. Therefore, this study investigated the retrofitting capacity of external devices (ENTA damper systems) for reinforced concrete (RC) frames in term of enhancing their resistance under the combined effects of blast and seismic loads. This study presents the establishment of finite element (FE) models for retrofitted RC frames with ENTA damper systems through the utilization of the dynamic analysis software LS-DYNA. The investigation involved the validation for blast performance of RC column in order to identify the most effective method for modeling blasts. Additionally, the study aimed to validate the performance of RC frame models through effects of ENTA damper systems under seismic loading. Subsequently, a performance evaluation of RC frame structures was carried out to examine the impact of the ENTA damper systems when subjected to blast loading. The findings of the study indicate that the use of external ENTA damper systems effectively enhanced the rigidity and structural integrity of RC frames, while maintaining their ability to resist deformation. Finally, the damage assessment of blast and seismic performance is investigated based on various parameters such as ductility, drift and energy-based damage limits.

Recent progress in polyvinyl alcohol (PVA)/nanocellulose composite films for packaging applications: A comprehensive review of the impact on physico‐mechanical properties

AbstractAs society advances, the demand for innovative and sustainable food processing techniques and materials has grown significantly. The food industry, especially the food packaging sector, faces the challenge of developing cost‐effective and sustainable packaging materials to meet consumers' increasing demands. One promising solution for this is the use of biodegradable polymers such as polyvinyl alcohol (PVA), but standalone PVA cannot meet the required properties of packaging materials. The use of nanocellulose (NC) as fillers has been intensively studied recently. This review article provides a comprehensive overview of existing studies focusing on the preparation of PVA/NC composite films for packaging applications. The effects of NC loading on the physico‐mechanical properties of these films, including tensile strength, elongation, water absorption/swelling behavior, barrier properties, and optical properties, have been thoroughly examined. Overall, the general findings suggest that the reinforcement of NC in the PVA polymer matrix leads to improvements in the films' properties. Specifically, the addition of NC enhances tensile strength, reduces O2, CO2, and water vapor transmission rates, and decreases the films' propensity to absorb moisture or swell under wet conditions. However, it is important to note that the presence of NC compromises the optical properties of the films by reducing transparency, and the NC content beyond threshold level reduces the feasibility of the composite film. By synthesizing these findings, this review underscores the potential of PVA/NC composite films as promising materials for packaging applications. Moving forward, further research efforts are warranted to optimize the formulation and processing of these composite films to strike a balance between mechanical strength and optical clarity, thus advancing their practical utility in the packaging industry.

Cobalt Promotion and Ni+Co Loading Effects of γ-Al2O3-Supported Ni–Co Catalysts for the Flue Gas Reforming of Methane

Cobalt Promotion and Ni+Co Loading Effects of γ-Al₂O₃-Supported Ni–Co Catalysts for the Flue Gas Reforming of Methane

A new method of rapid-intelligent assessment for the dynamic service performance in high-speed railway subgrade

ABSTRACT There is a lack of a rapid, advanced, and comprehensive method for assessing the dynamic service performance in high-speed railway subgrade, which leads to an inability to pre-assess the health state of the subgrades in advance. In this paper, an innovative method of rapid-intelligent assessment for the dynamic service performance (RADSP) in high-speed railway subgrade was proposed. Firstly, a large-scale exciter was used to simulate the train loading effect, which could rapidly obtain the assessment metrics for subgrade dynamic service performance, including subgrade dynamic response (SDR) and subgrade cumulative deformation (SCD), where the SDR includes dynamic stress and acceleration. Then, to explore the future development trend of SCD during operation, an intelligent and advanced prediction of SCD was conducted using the optimal machine learning (ML) prediction model. Finally, by combining the results of the SDR and SCD assessments to achieve the RADSP in high-speed railway subgrade. Moreover, the method was applied to assess the dynamic service performance of diatomaceous earth subgrade structures with four different waterproofing structure layers (WSL): the middle of subgrade surface layer (WSL-1), the bottom of subgrade surface layer (WSL-2), the middle of subgrade bottom layer (WSL-3), and the bottom of subgrade bottom layer (WSL-4). The results indicate that: 1) During the excitation experiments, the maximum values for SDR (dynamic stress, acceleration) and SCD exceed the respective limits of 50 kPa, 10 m/s2, and 15 mm under WSL-1 and WSL-4. 2) The ensemble model, AdaBoost-GPR, is selected as the optimal ML model to predict the SCD values. Notably, the prediction SCD value exceeds the 15 mm limit under WSL-3, indicating that the SCD during future operation does not meet the requirements for pre-assessment. 3) Under WSL-2, both SDR and SCD assessments satisfy the limit value requirements, indicating that the dynamic service performance is better. Based on the proposed method, it is found that when designing waterproof-drainage subgrade structures in diatomaceous earth areas, it is recommended to position the WSL at the bottom of subgrade surface layer. The research findings serve as a crucial reference and valuable lesson for the health monitoring of high-speed railway subgrades.

Effect of Torsional Load on Electrical and Mechanical Properties/Behaviour of Stretchable GNP-Ag Conductive Ink

Stretchable conductive inks (SCIs) have gained significant attention in recent years due to their potential applications in flexible and wearable electronics. Graphene nanoplatelet (GNP) hybridization conductive ink is a promising material for stretchable electronics due to its high electrical conductivity and excellent mechanical properties. However, the resistivity of GNP ink on flexible substrates can be affected by various factors, such as the torsion of the substrate. This paper aims to investigate the effect of torsional load in terms of the electrical and mechanical behaviour of hybridization conductive ink between GNP and Ag. The research was carried out on the formulation and performance of GNP hybrids using GNP and silver flakes (Ag). The GNP hybrid ink was printed on a copper substrate using a mesh stencil method and cured at 250 °C for an hour. The resistivity was evaluated at room temperature before and after the torsional tests in terms of electrical characteristics. The finding exposed that the resistivity values for each of the three samples of torsional tests significantly changed after 1000 cycles. Eventually, the resistance value at cycle 5000 rose due to the damaging impact of increasing the number of torsional cycles on the sample. In future work, it is recommended that the evaluation is made under temperature dependence and supported by SEM images.

Bending Performance of a Prestressed Concrete Composite Girder Bridge with Steel Truss Webs

An experiment was conducted on a prestressed concrete (PC) composite girder bridge with steel truss webs to investigate its flexural performance. The mechanical characteristics and failure modes of a PC composite girder bridge with steel truss webs was clarified. Finite element (FE) analysis was carried out, and the influence of the girder height-to-span ratio and eccentric loading effect on the flexural performance of a composite beam bridge with a steel truss web was discussed. The method for calculating the cracking bending moment, the bending moment at the rebar yield stage, and the ultimate bending moment of a PC composite girder with steel truss webs was proposed. Key findings include that, in both the elastic and cracking elastic stages, the strain of the bottom and top conforms to the plane-section assumption. Throughout the loading process, there was no occurrence of joint failure or local buckling failure in the steel truss webs; the composite girder ultimately fails due to excessive deformation, indicating that the overall mechanical performance of the composite beam is good. The deflection and stress in the mid-span section decrease with an increasing height-to-span ratio, and there are significant impacts of eccentric loading on deflection and stress. Compared with the results of the FE analysis and test, the calculation methods of the cracking moment, reinforcement yield moment, and ultimate moment of PC composite girders with steel truss webs presented in this paper have a high accuracy.

Effects of Zn loading on ZnxCo1−xCo2O4 spinel catalysts for low-temperature catalytic decomposition of N2O in the presence of inhibitors

The recent advancement of NH3-based fuel demands the development of catalysts that can decompose N2O at low temperatures and are stable against various inhibitors. Zn-doped cobalt spinel (ZnxCo1−xCo2O4) catalysts have demonstrated superior activity for N2O decomposition at low temperatures. However, their optimization and deactivation mechanisms with respect to Zn loading when inhibitors are present require further investigation. Herein, we reviewed the effects of Zn loading on catalysts at low temperatures without or with the presence of inhibitors (3 vol% O2, 6 vol% H2O, 200 ppm NO). The results showed that adding an appropriate amount of Zn into Co3O4 spinel catalysts improves their N2O decomposition activity. The Zn-induced enhancement of the catalysts’ redox properties, and reducibility was the underlying mechanism behind the activity promotion. The presence of structural defects created through the addition of Zn enhanced the catalyst’s resistance to O2. The deactivation by H2O and NO upon the addition of Zn could be correlated with the reduced availability of surface Co species and Co2+ as adsorption-active sites and the stronger bond of Co with –NO, respectively. This study underscores the importance of controlling the Zn loading as a bulk redox promoter in ZnxCo1−xCo2O4 spinel catalysts for practical applications.

Supported Copper Nanoarchitecture for Selective Ethylbenzene Oxidation (EBO) Reaction

Copper-based (Cu-NP) were uniformly dispersed on various inorganic supports (alumina, silica, titania, and zirconia) were prepared by the reverse microemulsion technique. These nanoparticles were used for the selective oxidation of ethylbenzene (EB) to produce acetophenone (AP) as the main product in the presence of Tert-butyl hydroperoxide(TBHP) as an oxidant. This study focused on creating Cu-nanoparticles evenly dispersed on alumina using varying Cu-loadings (5%, 10%, and 15% wt.) and Brij-35 as the surfactant. The resulting catalytic material was characterized using various physicochemical techniques like XRD, FESEM, HRTEM, XPS and physisorption techniques. Various parametric studies were conducted, such as the effects of temperature, catalyst support, catalyst loading, and TBHP loading to optimize the EB conversions and AP selectivity. Among the various catalyst loadings, 15% CuO/Al2O3 (15% of the copper content) nanocomposites showed exceptional performance, with the highest EB conversion rate (99.7%) and AP selectivity (98.5%) compared to other nanocomposites. The catalyst's stability and recyclability over four cycles were attributed to the strong copper oxide-alumina interaction. These findings suggest that this nanocomposite material is a promising candidate for catalytic applications, offering high selectivity and consistent EB conversion rates.

Pilot evaluation of allostatic load and breast cancer characteristics in a predominantly Han Chinese population.

e12570 Background: To determine the effects of allostatic load (AL), a measure of cumulative physiological effects of chronic stress due to adverse social determinants of health, on breast cancer (BC) characteristics in Chinese individuals. Methods: A pilot sample of185 women with newly diagnosed BC at Sichuan People’s hospital from 2018 to 2023 and complete AL data were included. AL used 10 markers (total cholesterol, low-density lipoprotein, albumin, glomerular filtration rate, white blood cell count, C-reactive protein, systolic and diastolic blood pressure, body mass index and heart rate). AL was assigned 1 point for each marker value in the worst quartile. The sum of the points represented the AL composite measure. Using linear and logistic regression, we determined the association of AL with age and educational attainment and with tumor ER+ and PR+ status. Results: Participants were 98.37% Han Chinese, mean age 51 (range 27-78). 23.24% attained college-level education or above. Higher AL trended to correlate with less than college-level educational attainment (coefficient=-0.60, p=0.058). In a univariable model, AL correlated with ER+ (OR=0.80, P=0.039) and PR+ (OR=0.81, P<0.001) BC. Adjusting for age and educational attainment, AL trends remained positive but not significant with ER+ BC (OR =0.82, P=0.092). Conclusions: Similar to US patients, AL may represent a physiologic correlate of adverse social conditions and worse BC characteristics. Results remain to be confirmed in a larger population.

Graphitization transformation of aluminum electrolytic spent carbon cathode

Aluminum electrolysis spent cathode carbon (SCC), as typical solid hazardous waste, poses significant environmental risks. Harmless treatment of SCC and recycling of its carbon component are important research areas. In this study, SCC was subjected to microwave hydrothermal acid leaching to remove harmful components, followed by the production of high-quality graphite via iron-catalyzed graphitization. The effects of reaction temperature, heating time, and catalyst loading on the graphitization conversion of SCC were investigated. The catalytic graphitization process of SCC was optimized using the response surface method. The results show that when the reaction temperature is 1520 °C, the heating time is 85.24 min, and the catalyst loading is 46.15 wt%, the graphitization degree of the sample is 97.61 %. The samples prepared under the optimal conditions were characterized using XRD, Raman, SEM, and TEM. The results reveal that the catalytic graphitization process significantly influences the conversion of microcrystalline structures in SCC into graphite structures. The iron-catalyzed transformation of microcrystalline carbon was analyzed to elucidate the graphitization transformation mechanism. This study offers an effective pathway for the high-value utilization of SCC. It also serves as a technical reference for the catalytic graphitization conversion of carbon materials.

Effect of dopant loading and calcination conditions on structural and optical properties of ZrO2 nanopowders doped with copper and yttrium

Undoped, Cu and/or Y doped ZrO2 nanopowders were synthesized with Zr, Y, and Cu nitrates using a co-precipitation approach. Their structural and optical properties were examined regarding dopant content (0.1–8.0 mol.% of CuO and 3–15 mol.% of Y2O3) and calcination conditions (400 °C–1000 °C and, 1,2 or 5 h) through Raman scattering, XRD, TEM, EDS, AES, EPR, UV–vis and FTIR diffused reflectance methods. The results showed that both Cu and Y dopants promoted the appearance of additional oxygen vacancies in ZrO2 host, while the formation of tetragonal and cubic ZrO2 phases was primarily influenced by the Y content, regardless of Cu loading. The bandgap of most of the powders was observed within the 5.45–5.65 eV spectral range, while for those with high Y content it exceeded 5.8 eV. The (Cu,Y)-ZrO2 powders with 0.2 mol.% CuO and 3 mol.% Y2O3 calcined at 600 °C for 2 h demonstrated nanoscaled tetragonal grains (8–12 nm) and a significant surface area covered with dispersed CuxO species. For higher calcination temperatures, the formation of CuZr 2+ EPR centers, accompanied by tetragonal-to-monoclinic phase transformation, was found. For fitting of experimental FTIR reflection spectra, theoretical models with one, five, and seven oscillators were constructed for cubic, tetragonal, and monoclinic ZrO2 phases, respectively. Comparing experimental and theoretical spectra, the parameters of various phonons were determined. It was found that the distinct position of the high-frequency FTIR reflection minimum is a unique feature for each crystalline phase. It was centered at 700–720 cm−1, 790–800 cm−1, and 820–840 cm−1 for cubic, tetragonal, and monoclinic phases, respectively, showing minimal dependence on phonon damping coefficients. Based on the complementary nature of results obtained from structural and optical methods, an approach for monitoring powder properties and predicting catalytic activity can be proposed for ZrO2–based nanopowders.

Study of a mechano-electrochemical model: a numerical and experimental approach

The mechanochemical effects of elasticity and plasticity are introduced into a peridynamic (PD) corrosion model. A PD equation that couples the mechanics and kinetics of electrochemistry is proposed for the first time. This clarifies the influence of the mechanical load in governing the occurrence of diffusion during corrosion. The phase changes experienced by a material are used to characterize the movement of the corrosion boundary, and the concentration of material points is used to characterize the degree and extent of damage caused to the chosen metal. Immersion tests and in situ electrochemical tests are carried out, and the results are used to explore the effects of stress and/or load on the kinetics of environment-induced damage to an aluminum alloy. The model predictions are in good agreement with the experimental observations. The results of this study demonstrate that a coupled mechano-electrochemical PD corrosion model can capture corrosion-induced damage and can be used to study damage propagation upon exposure to an aggressive environment.

An improved golden jackal optimization algorithm for combined economic emission dispatch problems

In this research paper, a new improved golden jackal optimization (IGJO) algorithm is applied to address the combined economic emission dispatch (CEED) problem, along with various thermal generator constraints such as valve point loading (VPL) effect, generator limits (GL) in power system. The hunting behavior of the golden jackals is mimicked in the golden jackal optimization (GJO) algorithm. The main aim of the CEED problem is to find the best optimal generation scheduling while minimizing both fuel cost and emission besides meeting the different power system constraints. The original GJO algorithm faces challenges when dealing with high-dimensional optimization problems, as it tends to get trapped in local optima. To address this issue the opposition-based learning (OBL) method was adopted in this GJO algorithm to obtain the global optimal solution and ensure enhanced performance in finding the solution for the CEED problems. To assess the competitiveness of the IGJO algorithm, it is used for various CEED test problems available in the literature, and results are contrasted with other recent heuristic optimization algorithms. Simulation results show that the proposed IGJO performs more effectively than the other compared algorithms in terms of solution quality, and robustness.