Response Behavior Research Articles

A Hidden Convexity of Nonlinear Elasticity

A technique for developing convex dual variational principles for the governing PDE of nonlinear elastostatics and elastodynamics is presented. This allows the definition of notions of a variational dual solution and a dual solution corresponding to the PDEs of nonlinear elasticity, even when the latter arise as formal Euler–Lagrange equations corresponding to non-quasiconvex elastic energy functionals whose energy minimizers do not exist. This is demonstrated rigorously in the case of elastostatics for the Saint-Venant Kirchhoff material (in all dimensions), where the existence of variational dual solutions is also proven. The existence of a variational dual solution for the incompressible neo-Hookean material in 2-d is also shown. Stressed and unstressed elastostatic and elastodynamic solutions in 1 space dimension corresponding to a non-convex, double-well energy are computed using the dual methodology. In particular, we show the stability of a dual elastodynamic equilibrium solution for which there are regions of non-vanishing length with negative elastic stiffness, i.e. non-hyperbolic regions, for which the corresponding primal problem is ill-posed and demonstrates an explosive ‘Hadamard instability;’ this appears to have implications for the modeling of physically observed softening behavior in macroscopic mechanical response.

Electromagnetic-mechanical response mechanism and microstructure evolution during Al-Mg electromagnetic pulse welding

Electromagnetic pulse welding technology can achieve effective bonding of different metals without intermetallic compounds and heat-affected zones. Current research primarily focuses on bonding interface and strength, neglecting the fact that the strength of the joint is also related to the performance of the plate itself. This study investigates the macro-microscopic responses, and relevant mechanisms of plates under electromagnetic-mechanical coupling effects are revealed by the integration of microscopic characterization, a finite element model, and mechanical tests. The results show that diverse crystal structures have different mechanical response behavior. The elongation of aluminum after pure pulsed electromagnetic field (EMF) treatment is 27% higher than the untreated specimen while the tensile strength remains the same. But magnesium alloys show an increase of 16%, and 23% for tensile strength, and elongation, respectively. Under a pure EMF, the movement and recombination of dislocations are promoted in aluminum alloy, which is beneficial to reducing the dislocation density of aluminum alloy. As for magnesium alloy, twinning and recrystallization are induced to realize grain refinement. Under the coupling of electromagnetic-mechanical, there is an interaction between the electromagnetic effect and strain rate hardening on dislocations. The tensile strength of the Al specimen increases first and then decreases with the discharge voltage rising. This is determined by the dislocation entanglement behavior. This paper can provide a reference for an in-depth understanding of the mechanism and welding process of electromagnetic pulse welding.

Housing-Resources Spatial Mismatch Investigation of Affordable Housing and Policy Implementation: A Case Study from Hangzhou, China

Intensive spatial transformation and restructuring in China these years has brought the separation of residence-job, so as to residence-public services, which adversely affects people’s access and enjoyment of job and public service resources, especially for the disadvantaged populations with limited choice of residence location and insufficient access to those resources. The residents of affordable housing are among the typical disadvantaged populations under the existing affordable housing policy in China. Residence-job separation of affordable housing residents has been paid much attention in literature, but no specific study has been conducted on the residence-public services separation and the behavioral responses of the residents. Spatial mismatch theory was originally put forward to reveal the adverse labor market outcome brought about by residence-job separation, and nowadays some scholars have tried to extend the residence-job spatial mismatch to residence-other resource spatial mismatch. This research responds to both the dilemma facing by the disadvantaged affordable housing residents and the extension trend of spatial mismatch theory. By applying the spatial mismatch theory and taking several affordable housing communities of Hangzhou as examples, the study explore the problems existing in affordable housing in commuting, employment, public service and residents' behavior response. The results found that the current affordable housing policy has led to an increase in commuting costs, a decrease in employment accessibility and welfare, a decrease in accessibility and satisfaction of public services, and disruptive behavior in the affordable housing market. These problems are mainly caused by remote layout and single supply, unreasonable allocation methods, difficulty in exchanging housing units and inadequate supervision of undesirable behaviors. To alleviate the spatial mismatch between housing and resources in Hangzhou, policy suggestions could be considered from four aspects: housing layout and supply, allocation methods, housing exchange and supervision.

Itch and Pain Behaviors in Irritant Contact Dermatitis Produced by Sodium Lauryl Sulfate in Mice.

Irritant contact dermatitis (ICD) is a nonspecific skin inflammation caused by irritants, leading to itch and pain. We tested whether differential responses to histamine-dependent and -independent pruritogens can be evoked in ICD induced by sodium lauryl sulfate (SLS). An ICD mouse model was established with 5% SLS in acetone versus a vehicle topically applied for 24 h to the cheek. Site-directed itch- and pain-like behaviors, occurring spontaneously and in response to mechanical, thermal, and chemical stimuli (histamine, ß-alanine, BAM8-22, and bradykinin) applied to the cheek, were recorded before (day 0) and after irritant removal (days 1, 2, 3, and 4). Skin inflammation was assessed through visual scoring, ultrasound, and measurements of skin thickness. SLS-treated mice exhibited hyperalgesia-like behavior in response to mechanical and heat stimuli on day 1 compared to the controls. SLS mice exhibited more spontaneous wipes (pain) but not scratching bouts (itch) on day 1. Pruritogen injections caused more scratching but not wiping in SLS-treated mice compared to the controls. Only bradykinin increased wiping behavior compared to saline. SLS-treated mice developed noticeable erythema, scaling, and increased skin thickness on days 1 and 2. SLS induced cutaneous inflammation and behavioral signs of spontaneous pain and itching, hyperalgesia to mechanical and heat stimuli and a chemical algogen, and enhanced itch response to pruritogens. These sensory reactions preceded the inflammation peak and lasted up to two days.

Modeling and simulation of laser-ignited Al-PTFE reactive material in vacuum

Despite extensive investigations elucidating the initial response behavior of aluminized polytetrafluoroethylene (Al-PTFE) under atmospheric pressure, research on their response in lean-oxygen environments pertinent to propulsion and explosion scenarios is still lacking. This paper theoretically analyzes the multi-physical processes of laser-ignited Al-PTFE, identifying the initial response, main chemical reaction paths, and gas-phase product flow mechanisms. A dynamic reaction model of Al-PTFE considering material moving front, chemical reactions, gas-phase product dynamics, and variations in thermophysical properties, was developed. The robust coupling scheme in the model addresses nonlinear equations and fluid-solid coupling boundary conditions. Validation was achieved by comparing the ablation depth and plume number density field calculated by the model with the experimental results in the literature. The model reveals a positive correlation between laser fluence and both temperature growth rate and ablation depth of Al-PTFE, with the effects mainly observed in the full width at half maximum (FWHM) of the pulsed laser due to the thermal decomposition of the PTFE matrix. Simulations of the equilibrium constants and molar fractions of 19 components in the Al-PTFE ablation plume within the temperature range of 2000 K to 30,000 K at 0.001 Pa indicate that the equilibrium constants for dissociative reactions exceed those for ionization reactions, primarily in the early plume formation stages. Analysis of kinetic parameters and ambient pressure effects shows that during laser ablation, the maximum temperature of the plume initially appears near the ablation surface, shifting to the front, where the maximum velocity is always located. An elliptical shock wave forms due to adiabatic expansion of the plume, creating a cavity inside the plume. Lower ambient pressure increases plume expansion velocity, temperature, and size.

A luminescent binuclear Cu(I) complex constructed by bipyridine, TD-DFT calculation, and its fluorescent sensing properties for VOCs

The design and research of materials with strong luminescence and fluorescence sensing for the detection of volatile organic compounds (VOCs) are of great significance and challenge. Herein, we report a binuclear Cu(I) complex, [Cu2(POP)2(MeCN)2(4,4′-bipy)](PF6)2 (2), which is synthesized rationally through a substitution reaction between complex [Cu(POP)(4-PBO)(MeCN)](PF6) (1) and 4,4′-bipy lignand (POP is bis[2-(diphenylphosphino)phenyl]ether, 4,4′-bipy is bipyridine, 4-PBO is 2-(4′-pyridyl)-benzoxazole). The complex 2 was characterized by single-crystal X-ray diffraction as an isolated binuclear structure constructed by a bridged 4,4′-bipy ligand. Under UV irradiation, both the powder and doped thin film of 1 and 2 exhibit broadband photoluminescence emission. The TD-DFT calculation reveals the details of the electronic transitions corresponding to the light absorption and emission of the two complexes, and also illustrates that the improved luminescence of 2 compared to 1 is due to the T1 excited state transforms from a localized transition to a charge transfer transition similar to the S1 excited state and the extremely small energy gap ΔE(S1-T1) value of 0.09 eV (2). Based on these complexes, fluorescent test strips were developed. It is gratifying to find that the test strip based 2 shows a distinguishable fluorescence response behavior to a variety of VOCs. Especially, the test strip showed a rapid quenching fluorescence response to acetophenone, and a rapid quenching followed by rapid enhancement fluorescence response to acetonitrile. Therefore, it can be used for rapid and highly selective fluorescence sensing detection of acetonitrile and acetophenone.

Limited Bedding and Nesting as a Model for Early-Life Adversity in Mice.

Early-life adversity (ELA), such as abuse, neglect, lack of resources, and an unpredictable home environment, is a known risk factor for developing neuropsychiatric disorders such as depression. Animal models for ELA have been used to study the impact of chronic stress on brain development, and typically rely on manipulating the quality and/or quantity of maternal care, as this is the major source of early-life experiences in mammals, including humans. Here, a detailed protocol for employing the Limited Bedding and Nesting (LBN) model in mice is provided. This model mimics a low-resource environment, which provokes fragmented and unpredictable patterns of maternal care during a critical developmental window (postnatal days 2-9) by limiting the amount of nesting materials given to the dam to build a nest for her pups and separating the mice from the bedding via a mesh platform in the cage. Representative data are provided to illustrate the changes in maternal behavior, as well as the diminished pup weights and long-term changes in basal corticosterone levels, that result from the LBN model. As adults, offspring rearedin the LBN environment have been shown to exhibit an aberrant stress response, cognitive deficits, and anhedonia-like behavior. Therefore, this model is an important tool to define how the maturation of stress-sensitive brain circuits is altered by ELA and results in long-term behavioral changes that confer vulnerability to mental disorders.

Seismic behavior of high-rise modular buildings with simplified models of inter-module connections

Inter-module connections serve as crucial components, horizontally and vertically connecting individual modules to form modular buildings. This paper presents a component-based model that divides inter-module connections into vertical and horizontal connection components, facilitating the simplification of shear and axial behaviors for input into the global numerical model. Initially, experimental studies and numerical simulations were conducted to investigate the shear and axial behavior of these connection components, following which simplified connection component models were derived. Subsequently, a component-based model of inter-module connections was established, in which the shear and axial properties of the vertical and horizontal components were represented by nonlinear connector elements. Finally, the proposed component-based model was incorporated directly into the global frame models of high-rise steel modular buildings, and the seismic behavior was evaluated. The accuracy of the proposed component-based model was investigated by comparing the natural vibration characteristics and global building responses of high-rise steel modular buildings with traditional empirical models established based on assumptions of rigid or pinned fixities. The results reveal that traditional empirical models fail to accurately represent the discontinuous properties of inter-module connections, resulting in an overestimation of structural lateral stiffness. In contrast, the component-based model accounts for the actual load-transfer mechanisms of vertical and horizontal components, providing a more accurate understanding of the natural vibration characteristics and seismic response of high-rise steel modular buildings. The proposed component-based model establishes a critical link between isolated connection behavior and structural response assessment for high-rise steel modular buildings, making it well-suited for accurately predicting global building responses.

Construction of “island-bridge” microstructured conductive coating for enhanced impedance response of organohydrogel strain sensor

Flexible conductive hydrogels (CHs) have received widespread attention in the field of wearable strain sensor, electronic skin, and artificial intelligence owing to their excellent stretchability, biocompatibility, and real-time sensing performance. However, it still remains a critical challenge to design and construct the satisfactory wearable strain sensor integrated with high sensitivity, wide sensing range, and environmental stability, especially at extreme temperatures. Herein, ionic conductive polyacrylamide/sodium alginate nanocomposite organohydrogel anchored with electronic conductive “island-bridge” microstructured carbon nanotubes (CNTs) conformal coating was designed and fabricated for high-performance strain sensor, of which the existence of “island-bridge” microstructured electronic conductive layer and its special structure evolution upon external stretching can significantly enhance the alternating current impedance response behavior of the sensor, featuring with a high sensitivity of 76.54 at 600 % strain, wide sensing range (0–600 % strain), fast responsiveness (110 ms), extremely low detection limit (0.1 %), and favorable stability and reproducibility of over 3200 cycles. Meanwhile, the resultant organohydrogel strain sensor can precisely detect and differentiate complicated human activities even at the environment temperatures of −30 °C and 50 °C, opening a promising avenue for next-generation smart wearable electronics.

Where nonresponse is at its loudest: Cross-country and individual differences in item nonresponse across the PISA 2018 student questionnaire

The Programme for International Student Assessment (PISA) student questionnaire, despite being designed for low cognitive demand, may induce test burden due to its 306-item length, resulting in increased item nonresponse toward the questionnaire’s end. Using the PISA 2018 response data from 80 countries and a cross-classified mixed effects model, this study explored the average, cross-country, and individual nonresponse trends throughout the questionnaire. The average nonresponse probability increased from 2% at the questionnaire’s start to 11% at its end. East Asian countries displayed the flattest nonresponse trends, while South American countries showed the steepest. Individual differences were also prominent: students with a lower initial nonresponse propensity experienced a steeper increase in their nonresponse propensity as they progressed through the questionnaire, whereas those with a higher initial propensity remained at a relatively constant level. Our findings highlight the importance of the questionnaire design, the context in which it is administered, and its interaction with individual and cultural factors in shaping student response behavior. We discuss the implications for questionnaire design and researchers using PISA student questionnaire data for secondary analysis.

Elevated unanticipated acoustic startle reactivity in dyslexia.

People with dyslexia, a neurodevelopmental disorder of reading, are highly attuned to the emotional world. Compared with their typically developing peers, children with dyslexia exhibit greater autonomic nervous system reactivity and facial behaviour to emotion- and empathy-inducing film clips. Affective symptoms, such as anxiety, are also more common in children with dyslexia than in those without. Here, we investigated whether the startle response, an automatic reaction that lies at the interface of emotion and reflex, is elevated in dyslexia. We measured facial behaviour, electrodermal reactivity (a sympathetic nervous system measure) and emotional experience in response to a 100 ms, 105 dB unanticipated acoustic startle task in 30 children with dyslexia and 20 comparison children without dyslexia (aged 7-13) who were matched on age, sex and nonverbal reasoning. Our results indicated that the children with dyslexia had greater total facial behaviour and electrodermal reactivity to the acoustic startle task than the children without dyslexia. Across the sample, greater electrodermal reactivity during the startle predicted greater parent-reported anxiety symptoms. These findings contribute to an emerging picture of heightened emotional reactivity in dyslexia and suggest accentuated sympathetic nervous system reactivity may contribute to the elevated anxiety that is often seen in this population.

Multi-decadal trophic shifts in Lake Erie Yellow Perch Perca flavescens

In Lake Erie, yellow perch Perca flavescens support vast commercial and recreational fisheries, yet populations have recently declined. Using N=5,889 yellow perch stomachs collected from 1997 to 2021, we explore trends in the feeding ecology and trophic level of yellow perch with generalized additive models (GAMs). Models revealed a significant decrease in yellow perch trophic level (-0.15 trophic levels in the last decade), and significant dietary shifts. Yellow perch have shifted away from feeding on piscine prey and round goby Neogobius melanostomus over the 25-year time series, and now feed on invertebrates more frequently – including invasive waterfleas (Bythotrephes longimanus and Cercopagis pengoi) and Chironomids. Dietary patterns appear to reflect broad ecological changes – invasive waterfleas have proliferated while populations of forage fish and round goby have declined. Furthermore, hypoxia events have increased in duration and severity, which may explain observed increases in Chironomid consumption, which are hypoxia tolerant. This study demonstrates trophic adaptability in yellow perch, which have changed feeding behavior and trophic position in response to novel invaders and changing environmental conditions.

Optimizing Processing Parameters for NR/EBC Thermoplastic Vulcanizates: A Comprehensive Full Factorial Design of Experiments (DOE) Strategy.

This research explores the development of thermoplastic vulcanizate (TPV) blends derived from natural rubber (NR) and ethylene-butene copolymer (EBC) using a specific blend ratio and melt mixing technique. A comprehensive full factorial design of experiments (DOE) methodology is employed to optimize the processing parameters. TPVs are produced through dynamic vulcanization, combining rubber crosslinking and melt blending within a thermoplastic matrix under high temperatures and shear. The physico-mechanical properties of these TPVs are then analyzed. The objective is to enhance their mechanical performance by assessing the influence of blend ratio, mixing temperature, rotor speed, and mixing time on crucial properties, including tensile strength, elongation at break, compression set, tear strength, and hardness. Analysis of variance (ANOVA) identifies the optimal processing conditions that significantly improve material performance. Validation is achieved through atomic force microscopy (AFM), confirming the phase-separated structure and, thus, the success of dynamic vulcanization. Rubber process analyzer (RPA) and dynamic mechanical analyzer (DMA) assessments provide insights into the viscoelastic behavior and dynamic mechanical responses. Deconvolution analysis of temperature-dependent tan δ peaks reveals intricate microstructural interactions influencing the glass transition temperature (Tg). The optimized TPVs exhibit enhanced stiffness and effective energy dissipation capabilities across a wide temperature range, making them suitable for applications demanding thermal and mechanical load resistance. This study underscores the pivotal role of precise processing control in tailoring the properties of NR/EBC TPVs for specialized industrial uses. It highlights the indispensable contribution of the DOE methodology to TPV optimization, advancing material science and engineering, particularly for industries requiring robust and flexible materials.

Phenotypic memory in quorum sensing.

Quorum sensing (QS) is a regulatory mechanism used by bacteria to coordinate group behavior in response to high cell densities. During QS, cells monitor the concentration of external signals, known as autoinducers, as a proxy for cell density. QS often involves positive feedback loops, leading to the upregulation of genes associated with QS signal production and detection. This results in distinct steady-state concentrations of QS-related molecules in QS-ON and QS-OFF states. Due to the slow decay rates of biomolecules such as proteins, even after removal of the initial stimuli, cells can retain elevated levels of QS-associated biomolecules for extended periods of time. This persistence of biomolecules after the removal of the initial stimuli has the potential to impact the response to future stimuli, indicating a memory of past exposure. This phenomenon, which is a consequence of the carry-over of biomolecules rather than genetic inheritance, is known as "phenotypic" memory. This theoretical study aims to investigate the presence of phenotypic memory in QS and the conditions that influence this memory. Numerical simulations based on ordinary differential equations and analytical modeling were used to study gene expression in response to sudden changes in cell density and extracellular signal concentrations. The model examined the effect of various cellular parameters on the strength of QS memory and the impact on gene regulatory dynamics. The findings revealed that QS memory has a transient effect on the expression of QS-responsive genes. These consequences of QS memory depend strongly on how cell density was perturbed, as well as various cellular parameters, including the Fold Change in the expression of QS-regulated genes, the autoinducer synthesis rate, the autoinducer threshold required for activation, and the cell growth rate.

Deformation Behavior of AZ31 Magnesium Alloy with Pre-Twins under Biaxial Tension.

In the present study, the mechanical response and deformation behavior of a Mg AZ31 plate with different types of pre-twins was systematically investigated under biaxial tension along the normal direction (ND) and transverse direction (TD) with different stress ratios. The results show that significant hardening was observed under biaxial tension. The yield values in the direction of larger stress values were higher than those under uniaxial loading conditions, and the solute atom segregation at twin boundaries generates more obvious strengthening effect. Noting that, for TRH (with cross compression along the rolling direction (RD) and TD and annealing at 180 °C for about 0.5 h) sample, the strength effect of the RD yield stress σRD:σND = 2:1 was higher than that of the ND yield stress under stress ratio σRD:σND = 1:2. There is a complex competition between twinning and detwinning under biaxal tension along the ND and TD of the pre-twinned samples with the variation in the stress ratio along the TD and RD. The variation in the twin volume fractions for all samples under biaxial firstly decreases and then increases with a higher stress ratio along the ND. As for the TDH sample (precompression along the TD and annealing), the changes of the twin volume fraction were lower than that of the TR sample (cross compression along the TD and RD). However, the amplitude of variation in twin volume fraction of the TRH sample is higher than that of the TR sample. This is because the relative activity of detwinning decreases and that of twinning increases, as the ND stress mainly leads to the growth of pre-twins and the TD stress often promotes detwinning of primary twins. With a higher stress ratio along the ND, the activity of twinning deformation increases and that of detwinning decreases.

Securing demand–response in smart grids against false pricing attacks

Two-way communication systems in smart grids help to engage consumers in demand–response programs, which can bring many benefits but also make smart grids vulnerable to cyber attacks. In this paper, a cyber attack which aims to disturb the demand–response process by injecting false electricity price signals is considered. A real-time pricing model where the operator has incomplete knowledge of the private demand–response behaviors of the customers is proposed. The vulnerability of the power system to false pricing attacks is analyzed by a Markov decision process, and the dynamic interaction between the attacker and the defender is modeled as a zero-sum Markov game where neither player has full information of the game model. For the solution of the Markov game, a model-free multi-agent reinforcement learning method is proposed to find the Nash Equilibrium policies for both players. The proposed method is applied to the IEEE 34 Node Test Feeder, in which the effect of the defense on mitigating the impact of the attack is demonstrated and different policies of the players given various resources are analyzed. The results shows that the studied cyber attack can cause a maximum of 1.96% unsatisfied load and the proposed defense measure can reduce the unsatisfied load by 50%–70% compared with the cases without defense measures.

Electro-thermal actuation in recycled aggregate concrete with rapid self-reinforcement via smart cement-based composites

With the growing call for low-carbon and environmentally friendly materials, recycled aggregate concrete (RAC) holds great promise for sustainable development. Nevertheless, significant challenges exist with respect to the material’s poor flexural carrying capacity. Development of an effective method for improving the flexural carrying capacity of RAC under a specific deflection deformation is important for enhancing the range of its structural applications. In this study, an intelligent structural optimisation strategy for compounding RAC with carbon-fibre (CF) reinforced cement-based composites (CFRCs) to realize rapid self-reinforcement via electro-thermal actuation is proposed. As a smart component, CFRC was first researched to investigate its electrical, mechanical, and microscopic properties. The optimal properties were obtained in specimens incorporating 0.5 vol%, CFRC0.5. CFRC0.5 exhibits an electrical resistivity of approximately 0.39 Ω∙m, accompanied by 65.3 % and 33 % increases in flexural and compressive strengths, respectively, when compared to the control mixture without CF. Furthermore, CFRC0.5 can maintain outstanding stability after multiple electro-thermal cycles. Analysis via microscopic characterisation revealed that a satisfactory conductive network can be formed at 0.5 vol% CF. Furthermore, CFs with excellent dispersity are particularly advantageous in improving the mechanical biting force within the cement matrix and restraining the further formation and expansion of microcracks. Thus CFRC0.5 was designed and fabricated as a pre-stress controller to realise rapid structural self-reinforcement, resulting in a 38.6 % improvement in the flexural carrying capacity of the RAC under specific midspan deflection conditions. Additionally, a response behaviour model for midspan deflection with temperature differential was established, showing an excellent correlation between the experimental results and theoretical simulation. This findings from this study highlight the significance of leveraging intelligent techniques to realise rapid self-reinforcement capabilities in concrete structures, facilitating their potential application in smart and adaptive structures.

The Pathobiology of Behavioral Changes in Multiple System Atrophy: An Update.

While cognitive impairment, which was previously considered a red flag against the clinical diagnosis of multiple system atrophy (MSA), is a common symptom of this rare neurodegenerative disorder, behavioral disorders are reported in 30 to 70% of MSA patients. They include anxiety, apathy, impaired attention, compulsive and REM sleep behavior disorders (RBD), and these conditions, like depression, are early and pervasive features in MSA, which may contribute to disease progression. Despite changing concepts of behavioral changes in this synucleinopathy, the underlying pathophysiological and biochemical mechanisms are poorly understood. While specific neuropathological data are unavailable, neuroimaging studies related anxiety disorders to changes in the cortico-limbic system, apathy (and depression) to dysfunction of prefrontal-subcortical circuits, and compulsive behaviors to impairment of basal ganglia networks and involvement of orbito-frontal circuits. Anxiety has also been related to α-synuclein (αSyn) pathology in the amygdala, RBD to striatal monoaminergic deficit, and compulsive behavior in response to dopamine agonist therapy in MSA, while the basic mechanisms of the other behavioral disorders and their relations to other non-motor dysfunctions in MSA are unknown. In view of the scarcity of functional and biochemical findings in MSA with behavioral symptoms, further neuroimaging and biochemical studies are warranted in order to obtain better insight into their pathogenesis as a basis for the development of diagnostic biomarkers and future adequate treatment modalities of these debilitating comorbidities.

Oxygen transport mechanism and the effect of microstructure on the oxygen response behavior of an oxygen-sensitive composite Ce0.9Gd0.1O2-ẟ – La0.6Sr0.4FeO3-ẟ at high temperature

Compositions like gadolinium doped cerium oxide Ce0.9Gd0.1O2-ẟ and strontium doped lanthanum ferrite La0.6Sr0.4FeO3-ẟ, or their composites are well known in the field of fuel cell electrolyte, oxygen transporting membrane and catalytic reactor applications. This work offers insight into composite material's oxygen response characteristics, taking Ce0.9Gd0.1O2-ẟ and La0.6Sr0.4FeO3-ẟ in 70: 30 wt percent. One pot sol-gel method was employed for the powder synthesis. The powder was characterized by TG-DSC, XRD, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). FESEM-EDX and EDX-line profiling techniques were used to check the compositional homogeneity of sintered bodies. Oxygen response tests were conducted from ambient (20 % O2) to 100 % O2 concentration, using bulk samples sintered at three different temperatures, i.e., 1000, 1150, and 1250 °C at a fixed soaking time of 4 hours. The sintered specimens' apparent porosity, bulk density, surface morphology, and electrical conductivity were also examined. The sintering temperature significantly impacts response behavior as the porosity and grain size of the sintered body plays a vital role in sensing performance. The mechanism of response towards oxygen is also discussed. Sample 73–100 displayed the best performance among others. We achieved the lowest response and recovery time of 15 – 48 sec and 45 – 80 sec from a 0.60 mm thick bulk material at 950 °C. Harsh environments were intentionally created to check the reliability and reproducibility of the response data. This material could be a good candidate as an oxygen gas sensor at high temperatures owing to its good sensitivity, reliability, reversibility, and stability.

A novel methodology to fabricate freestanding (CNFs-PVA)-MSP sensors in wireless humidity sensing applications

A novel methodology to fabricate freestanding (CNFs-PVA)-MSP sensors in wireless humidity sensing applications has been developed. This innovative fabrication methodology integrates a spin-coating technique with a unique magnetic sandwich fixture technology. Based on the developed sensor’s platform, the humidity sensing performance of the wireless sensors was studied at room temperature. The sensor’s signal, represented by the resonant frequency (RF), exhibits a linear correlation with relative humidity (RH). Models have been uncovered to describe the sensing behavior of the humidity response. Additionally, the RF alteration demonstrates a linear dependence on the thickness of the CNFs-PVA composite layer. This study systematically explores and discusses the sensitivity, response time, and cyclic humidity sensing stability of the MSP-based sensors. Remarkably, the MSP-based sensors exhibit good stability in humidity sensing throughout a seven-day cyclic test. In summary, this novel fabrication methodology not only enables the fabrication of diverse wireless organic material-MSP-based sensors with appealing overall wireless humidity sensing performance but also provides a novel methodology for crafting miniaturized organic material-ferromagnetic material double-layer devices, offering advantages such as simple handling, cost-effectiveness, and high fabrication efficiency.