Changes In Properties Research Articles

Understanding microplastic aging driven by photosensitization of algal extracellular polymeric substances

The aging of microplastics (MPs) is extremely influenced by photochemically-produced reactive intermediates (PPRIs), which are mediated by natural photosensitive substances. Algal extracellular polymeric substances (EPS) can produce PPRIs when exposed to sunlight. Nonetheless, the specific role of EPS in the aging process of MPs remains unclear. This work systematically explored the aging process of polystyrene (PS) MPs in the EPS secreted by Chlorella vulgaris under simulated sunlight irradiation. The results revealed that the existence of EPS accelerated the degradation of PS MPs into particles with sizes less than 1 µm, while also facilitating the formation of hydroxy groups on the surface. The release rate of dissolved organic matter (DOM) from PS MPs was elevated from 0.120 mg·L-1·day-1 to 0.577 mg·L-1·day-1. The primary factor contributing to the elevated levels of DOM was humic acid-like compounds generated through the breakdown of PS. EPS accelerated the aging process of PS MPs by primarily mediating the formation of triplet excited states (3EPS*), singlet oxygen (1O2), and superoxide radicals (O2∙-), resulting in indirect degradation. 3EPS* was found to have the most substantial impact. This study makes a significant contribution to advance understanding of the environmental fate of MPs in aquatic environments impacted by algal blooms.

Novel nanocomposite systems based on cesium dihydrogen phosphate: Electrotransport structural, morphological and mechanical characteristics

CsH2PO4 is a proton conductor belonging to the family of acidic salts and exhibits a monoclinic to cubic phase transition at 230 ± 2 °C with the conductivity jump of four orders of magnitude. To change the electrotransport and mechanical characteristics the non-oxide additives, such as detonation nanodiamonds, were firstly used as a dopant for proton nanocomposites based on cesium dihydrogen phosphate. The use of carbon containing materials has made it possible to create a new type of medium-temperature, highly conductive proton electrolytes. Influence of nanodiamonds (NDs) on the electrotransport, structural and thermodynamic properties of (1-x)CsH2PO4-xNDs (x-mole fraction, x = 0–0.99) electrolytes have been firstly investigated in detail by X-ray diffraction method, electrochemical impedance, FTIR-spectroscopy and differential scanning calorimetry. The CsH2PO4 (P21/m) exists in nanocomposites in the dispersed (up to 300 nm) and partially amorphous state resulting in the strong changes of the salt thermodynamic properties with increase of x mole fraction. The heterogeneous doping by non-oxide dopant resulted in the significant increase of the low temperature conductivity of 3.5 orders of magnitude due to interface interaction, while the superionic conductivity of nanocomposites remains close to the individual CsH2PO4 (∼10-2 S/cm) up to x = 0.7 (fvNDs = 11.7 %). The jump in the conductivity during the phase transition decreases significantly and almost disappears. The conductivity of nanocomposites decreases significantly only at x > 0.95 (fvNDs = 51.8 %) due to the percolation effect. The mechanical properties of CsH2PO4-NDs were shown to be much higher than of the individual CsH2PO4 even with small NDs content. Mechanism of nanocomposites formation is associated with the partial binding of CsH2PO4 protons by surface OH– groups of nanodiamonds. The results are important for the establishing and design the next generation membrane of fuel cells and nanocomposite electrodes for medium-temperature electrochemical devices.

Source-specified atmospheric age distribution of black carbon and its impact on optical properties over the Yangtze River Delta

Black carbon (BC) exerts a profound and intricate impact on both air quality and climate due to its high light absorption. However, the uncertainty in representing the absorption enhancement of BC in climate models leads to an increased range in the modeled aerosol climate effects. Changes in BC optical properties could result either from atmospheric aging processes or from variations in its sources. In this study, a source-age model for identifying emission sources and aging states presented by University of California at Davis/California Institute of Technology (UCD/CIT) was used to simulate the atmospheric age distribution of BC from different sources and to quantify its impact on the optical properties of BC-containing particles. The results indicate that regions with greater aged BC concentrations do not correspond to regions with higher BC emissions due to atmospheric transport. High concentrations of aged BC are found in northern Yangtze River Delta (YRD) regions during summer. The chemical compositions of particles from different sources and with different atmospheric ages differ significantly. BC and primary organic aerosols (POA) are dominating in Traffic-dominated source while other components dominate in Industry-dominated source. As the atmospheric age increases, the mass fraction of secondary inorganic aerosols rises. Compared to the original model, the simulated mass absorption cross section of BC particles in the source-age model decreases while the single scattering albedo increases. This compensates for ~11 % of the overestimation of the simulated BC direct radiative forcing. Our study highlights that incorporating atmospheric age and source information into models can greatly improve the estimation of optical properties of BC-containing particles and deepen our understanding of their climate effects.

Role of aging temperature on thermal stability of Co-free Cr0.8FeMn1.3Ni1.3 high-entropy alloy: Decomposition and embrittlement at intermediate temperatures

This study prepared a reduced activation single-phase Co-free Cr0.8FeMn1.3Ni1.3 high-entropy alloy (HEA) through arc melting, which exhibits great potential as a radiation-resistant material. The microstructural evolution and mechanical property changes of the alloy after prolonged aging at temperatures of 300, 500, and 700 °C were systematically studied using scanning and transmission electron microscopy (SEM/TEM/STEM) and electron probe microanalysis (EPMA) techniques. The results reveal that the alloy forms a single-phase FCC solid solution following cold deformation and subsequent recrystallization annealing. After prolonged aging at 300 °C for 1500 h, the microstructure of the alloy remains stable, maintaining a single-phase structure with minimal changes in mechanical properties. After aging at 500 °C for 1500 h, the alloy undergoes complex phase decomposition, giving rise to tetragonal σ-FeCr and L10-NiMn phases, along with minor amounts of Cr-rich BCC and Fe-rich FCC phases. During this stage, the interfaces between σ-FeCr and L10-NiMn phases undergo amorphization, leading to room-temperature embrittlement of the alloy. Following aging at 700 °C for 1500 h, the alloy precipitates the Cr-rich BCC phase, forming a dual-phase microstructure, resulting in increased tensile strength and reduced ductility. This study discloses the thermal stability of Cr0.8FeMn1.3Ni1.3 HEA through extended aging at 300 °C and 500–700 °C for up to 300 h, simultaneously providing reference values for evaluating the stability of other HEA systems. The occurrence of complex phase decomposition significantly impacts the mechanical properties of HEAs, necessitating cautious evaluation of their application potential.

Evaluation of the rheological properties and molecular distributions of asphalt binder under multiple aging and rejuvenating cycles (MARC)

Because of the widespread use of reclaimed asphalt pavement (RAP), various recycling agents (RAs) are developed and used in pavement engineering nowadays to restore the properties of RAP in asphalt mixes. Whereas there are many RA products available, it remains unclear on the fundamental rejuvenation mechanisms behind different RAs and the selection method of proper RA product to restore these recycled materials properties. In addition, there are important questions on hold in terms of RAP repeated recycling and the continuity of restoration capacity from these RAs. Therefore, this study is designed to track the properties changes of the asphalt binders in the context of multiple aging and rejuvenating cycles (MARC). Three different types of RA products are selected and evaluated using rheological characterization and chromatography (molecular distribution) analysis. Results show that the beneficial effects from RAs degrade over time with increase of aging/rejuvenating cycles. Two oils with their molecules that are mainly distributed in the medium molecular size (MMS) range, which compensate the loss of the MMS molecules of the base binder due to aging, show the good effectiveness in restoring not only the complex modulus but also the phase angle of the aged asphalt. And the good correlations between phase angle and MMS as well as LMS proportion indicate the fundamental relationship between binder’s molecular distribution and its rheological properties.

Experimental and numerical simulation research on hot dry rock wellbore stability under different cooling methods

The exploitation of geothermal energy commonly occurs at depths ranging from 3000 to 10000 m. At these depths, the surrounding rocks experience substantial temperature and pressure, leading to alterations in their physical and mechanical properties. The infiltration of drilling fluid into the wellbore result in thermal exchange with the surrounding rocks, causing a decrease in their strength and stability. Consequently, the wellbore becomes more susceptible to instabilities. This objective of this study was to investigate the physical and mechanical properties of heated granite under three distinct cooling methods: liquid nitrogen cooling, water cooling, and natural cooling. Based on experimental findings, this study enhanced the failure criteria for high-temperature granite and established a thermal-solid coupling model to assess the stability of wellbores in high-temperature granite formations. To examine the impacts of temperature variations between the wellbore and drilling fluid, analyze the stress distribution around the wellbore at various depths, and evaluate the consequences of high-temperature fluid intrusion on wellbore stability. The research indicates that: (1) Under identical high-temperature conditions, it has been observed that liquid nitrogen cooling causes the most significant damage to granite, followed by water cooling. On the other hand, natural cooling has the least detrimental effect on the rock. (2) With increasing temperature, the physical and mechanical properties of the rock undergo two distinct stages of change. The first stage is a gradual variation that occurs between 25 and 400 °C, while the second stage is a rapid variation observed between 400 and 800 °C. Notably, the temperature of 400 °C serves as a critical threshold for the observed property changes in this granite. (3) The rock failure criteria have been modified based on the thermal damage characteristics of cold fluid intrusion into granite and a thermal-hydraulic-mechanical coupled wellbore model has been established. (4) The numerical simulation results revealed that liquid nitrogen cooling had the greatest impact on wellbore temperature, stress, and damage zone. At 500 s, the temperature on the wellbore surface decreased by approximately 700 °C due to liquid nitrogen cooling. The circumferential stress and radial stress decreased by 180 MPa and 35 MPa, respectively. (5) After the intrusion of cold fluid into high-temperature granite, the stress around the wellbore decreases and the rate of decrease in circumferential stress is significantly greater than that of radial stress. This will increase the likelihood of wellbore instability.

Effects of Maillard reaction of different monosaccharide-modified on some functional properties of fish gelatin

In this work, the effects of Maillard reaction of different monosaccharide-modified fish gelatin were studied. The changes of gel properties, rheology and structure of fish gelatin before and after modification were compared and analyzed, and oil-in-woter emulsions were prepared. The results showed that the five-carbon monosaccharide had stronger modification ability than the six-carbon monosaccharide, which was mainly due to the different steric hindrance of the amino acids in the nuclear layer and the outer layer to the glycosylation reaction. With the progress of the Maillard reaction, the color of fish gelatin gradually became darker. The attachment of sugar chains inhibited the gelation process of fish gelatin, decreased the gelation rate, changed the secondary structure, increased the content of β-turn or α-helix, increased the degree of fluorescence quenching, and enhanced the emulsifying properties and emulsion stability. This study provides useful information for the preparation of different types of monosaccharide-modified proteins and emulsions.

Effect of zeolite and potassium application on changes in soil properties after harvest of maize

Effect of zeolite and potassium application on changes in soil properties after harvest of maize

Exploring the adsorption mechanisms of neurotransmitter and amino acid on Ti[formula omitted]C[formula omitted]-MXene monolayer: Insights from DFT calculations

In this study, we conducted a systematic density functional theory (DFT) investigation of the interaction between Ti3C2-MXene monolayer and biological molecules dopamine (DA) and serine (Ser) as neurotransmitter and amino acid, respectively. Our calculations show good agreement with previous literature findings for the optimized Ti3C2 monolayer. We found that DA and Ser molecules bind to the Ti3C2 surface with adsorption energies of -2.244eV and -3.960eV, respectively. The adsorption of Ser resulted in the dissociation of one H atom. Electronic density of states analyses revealed little changes in the electronic properties of the Ti3C2-MXene monolayer upon adsorption of the biomolecules. We further investigated the interaction of DA and Ser with Ti3C2 monolayers featuring surface-termination with OH functional group, and Ti-vacancy. Our calculations indicate that the adsorption energies significantly decrease in the presence of surface termination, with adsorption energies of -0.097eV and -0.330eV for DA and Ser, respectively. Adsorption energies on the Ti-vacancy surface, on the other hand, are calculated to be -3.584eV and -3.856eV for DA and Ser, respectively. Our results provide insights into the adsorption behavior of biological molecules on Ti3C2-MXene, demonstrating the potential of this material for biosensing and other biomedical applications. These findings highlight the importance of surface modifications in the development of functional materials and devices based on Ti3C2-MXene, and pave the way for future investigations into the use of 2D materials for biomedical applications.

Combined hydroxyphenyl-modified adhesive with the ion-pair strategy for long-lasting delivery of clonidine in single-layer matrix-type patch

Existing long-acting patches usually use controlled-release membranes to achieve constant rate delivery of the drug, which is complex and costly to prepare due to the 5-layer structure, so there is a necessity to develop a method to simplify the patch design and to control constant rate drug delivery. This study prepared a 7-day long-acting clonidine (CLO) patch using the ion-pair strategy based on hydroxyphenyl-modified pressure-sensitive adhesive (HP-PSA) and clarified the molecular mechanism of controlled delivery. Single factorial and central composite design (CCD) experiments were used to optimize the patch formulation, which was evaluated by a pharmacokinetic study. The controlled drug delivery mechanism was investigated by FTIR, 1H NMR, differential scanning calorimetry (DSC), confocal laser scanning microscopy (CLSM), molecular modeling, and rheology study. The optimized patch was formulated with 4.80% (w/w) CLO-AA (azelaic acid) as API and HP-PSA as PSA matrix and 95.00 μm thickness. The single-layer patch not only simplifies the preparation process but also has a zero-level skin penetration profile (r = 0.9592) in vitro. Compared with the commercial patch (AUC0-t = 7748.51 ± 662.76 h ng/ml, MRT0-t = 71.04 ± 9.30h), the pharmacokinetic behavior of the optimization group was semblable (AUC0-t = 8160.28 ± 694.04 h ng/ml, MRT0-t = 63.19 ± 12.38h). Mechanistic studies showed that ion-pair improved drug interaction with HP-PSA, leading to controlled drug release. Changes in drug physicochemical properties decreased skin permeability and increased drug-skin interaction, resulting in a constant delivery rate. In conclusion, the 7-day long-acting drug delivery of the CLO patch was achieved by the ion-pair strategy, which simplified the preparation process, and inspired a long-acting transdermal drug delivery system.

Prevalence and characteristics of patients prescribed opioids and central nervous system depression agents on discharge to hospice care.

Hospice patients with end-stage liver disease (ESLD) have an increased risk of adverse drug events due to physiological changes and changes in pharmacokinetic and pharmacodynamic properties of medications; however, the use of opioid and central nervous system (CNS) depressant prescribing among patients with ESLD is prevalent. This study quantified the frequency and distribution of opioid and concomitant respiratory and CNS depressant prescribing among hospice patients with ESLD compared to other common hospice diagnoses of cancer, chronic obstructive pulmonary disorder (COPD), heart failure, and end-stage renal disease. This was a cross-sectional study of adult (age 18 years or older) decedents of a large hospice chain. Patients included had a primary diagnosis of liver, cancer, cardiovascular, or respiratory disease. Among 119,424 hospice decedents, mean age of 77.9 years (standard deviation =13.5 years), 54.6% were female, and 58.9% were of a non-Hispanic white race. There was a similar frequency of prescribing a "scheduled" and "as needed [pro re nata (PRN)]" opioid or benzodiazepine in patients with ESLD compared to other common hospice diagnoses. In addition, there was a high prevalence of concurrent opioid and benzodiazepine prescriptions among patients with ESLD compared to cardiovascular and respiratory disease at admission (65.4% vs. 63.9% and 64.9%). Opioid requirements, oral morphine equivalent (OME) median [interquartile range (IQR)] at discharge were similar between cancer, liver, and respiratory disease, 120 OME [60-300], 120 OME [50-240], and 120 OME [50-240], respectively. We observed a high frequency of opioid and CNS depressant prescribing in a hospice patient population with ESLD which was similar to other common admitting hospice diagnoses.

Control, restructuring and temporal interpretation

In this paper, we investigate whether there is a correlation between the temporal properties of control verbs and the possibility of restructuring with obligatory control predicates, taking clitic climbing as a diagnostic for restructuring. We review the findings of previous studies on earlier stages of Portuguese and on (non-)standard varieties of contemporary European Portuguese. Additionally, we perform an analysis of both diachronic and synchronic corpus data, as well as of data collected through an acceptability judgement task. Based on our findings, we argue against a correlation between temporal dependence and restructuring and suggest that restructuring depends on the selectional properties of verbs, occurring when a functionally defective infinitive is selected. Diachronically, there is a change in the selectional properties of control verbs, whereas, synchronically, there is variation both across varieties and across speakers in the set of restructuring control verbs. Factors like the type of clitic and the presence of proclisis triggers affect the acceptability of clitic climbing.

Elastic modulus of cadaveric acetabular labrum correlates with ultrashort echo time (UTE) apparent spin-spin (T2*) and spin-lattice (T1) relaxation times

IntroductionThe acetabulum labrum plays a critical role in hip function. Medical imaging techniques for measuring changes in labral properties due to its degeneration may help improve our knowledge of its role in hip osteoarthritis (OA). This study aimed to explore the correlation between the mechanical properties of the acetabulum labrum and ultrashort echo time (UTE) MRI properties.Material and methodAcetabular labrum specimens were dissected from 12 fresh-frozen human cadaveric hip joints (64.6 ± 11.6 years old at the time of death, 7 female). UTE Cones sequences were used to measure apparent spin-spin (T2*) and spin-lattice (T1) relaxation times using a knee coil at 3 T in a clinical MR scanner. The stiffness and the elastic modulus (E) of the specimens were measured before MRI scans using uniaxial tensile tests. Spearman's rank correlation coefficients of Tendons' UTE-T2* and -T1 with their mechanical properties were calculated.ResultsThe human labrum specimen elastic modulus showed a significant inverse correlation with UTE-T2* (R = −0.66, P < 0.01) and with UTE-T1 (R = −0.56, P = 0.05). The stiffness of the specimens showed significant inverse correlations with UTE-T2* (R = −0.53, P = 0.01) and UTE-T1 (R = −0.63, P = 0.02).ConclusionThis study highlighted the potential of UTE-MRI techniques for the mechanical assessment of the acetabular labrum. UTE-MRI may improve labrum degeneration detection and monitoring, which requires further investigations.

Eu Doping in the GdCd7.88 Quasicrystal and Its Approximant Crystal GdCd6.

The effect of Eu doping in the Tsai quasicrystal (QC) GdCd7.88 and its periodic 1/1 approximant crystal (AC) GdCd6 are investigated. This represents the first synthesis of Eu-containing stable QC samples, where three samples with the final composition Gd1-xEuxCd7.6±α at Eu doping concentrations x = 0.06, 0.13, and 0.19 are obtained (α ∼ 0.2). They are compared to two 1/1 ACs with compositions Gd1-xEuxCd6 (x = 0.12, 0.16). In addition, a new type of 1/1 AC, differing only by the inclusion of extra Cd sites unique to the Eu4Cd25 1/1 AC, has been discovered and synthesized for the concentrations Gd1-xEuxCd6+δ (x = 0.25, 0.33, 0.45, 0.69, 0.73, and 0 < δ ≤ 0.085). Due to the preferred cube morphology of its single grains, we refer to them as c-type 1/1 ACs and to the conventional standard ones as s-type. In both QCs and s-type ACs, the Eu content appears to saturate at a concentration of ∼20%. On the other hand, any Gd| Eu ratio is allowed in the c-type ACs, varying continuously between GdCd6 and Eu4Cd25. We describe and contrast the changes in composition, atomic structure, specific heat, and magnetic properties induced by Eu doping in the quasicrystalline phase and the s-type and c-type 1/1 ACs. By comparing our results to the literature data, we propose that the occupancy of the extra Cd sites can be used to predict the stability of Tsai-type quasicrystalline phases.

Decreasing Photoreactivity and Concurrent Change in Dissolved Organic Matter Composition With Increasing Inland Water Residence Time

AbstractPhotochemical degradation of dissolved organic matter (DOM) has been the subject of numerous studies; however, its regulation along the inland water continuum is still unclear. We aimed to unravel the DOM photoreactivity and concurrent DOM compositional changes across 30 boreal aquatic ecosystems including peat waters, streams, rivers, and lakes distributed along a water residence time (WRT) gradient. Samples were subjected to a standardized exposure of simulated sunlight. We measured the apparent quantum yield (AQY), which corresponds to DOM photomineralization per photon absorbed, and the compositional change in DOM at bulk and individual compound levels in the original samples and after irradiation. AQY increased with the abundance of terrestrially derived DOM and decreased at higher WRT. Additionally, the photochemical changes in both DOM optical properties and molecular composition resembled changes along the natural boreal WRT gradient at low WRT (&lt;3 years). Accordingly, mass spectrometry revealed that the abundance of photolabile and photoproduced molecules decreased with WRT along the boreal aquatic continuum. Our study highlights the tight link between DOM composition and DOM photodegradation. We suggest that photodegradation is an important driver of DOM composition change in waters with low WRT, where DOM is highly photoreactive.

Evaluation of the impact of wastewater irrigation on the soil's dielectric parameters

AbstractThis study investigates the impact of wastewater irrigation on soil dielectric parameters, focusing on the often‐overlooked aspect of dielectric properties in contaminated soil. Wastewater, a significant contributor to soil and groundwater degradation, has long‐term effects on soil physical, chemical, and dielectric characteristics. Experimental measurements conducted overtime at 2.45 and 5.8 GHz frequencies reveal a correlation between wastewater irrigation and changes in dielectric properties. Emphasizing time variation as a pivotal independent variable, the study sheds light on its substantial influence on soil dielectric behavior. Notably, the research introduces an alternative methodology for the comprehensive evaluation of wastewater‐induced pollution effects on soil properties. This approach is substantiated by meticulous physicochemical analyses conducted on both pollution sources and the affected soil. The study further presents a robust response surface method‐based model, showcasing impressive accuracy with dielectric properties (ε′ and ε″) and penetration depth with R2 values of 0.9845, 0.9831, and 0.9528, respectively. Beyond unveiling crucial insights into the intricate interplay of wastewater and soil dielectric behavior, this research contributes to the development of effective strategies for pollution monitoring and management in soil ecosystems.

Behavior of high strength reinforcing steel rebars after high temperature exposure: Tensile properties and bond behavior using pull-out and end beam tests

High strength reinforcing steel (HSRS) is increasingly being adopted in the construction industry in North America due to its high load-carrying capacity, yet their behavior relative to normal grade rebars under external hazard events such as fire exposure still need further research. In current work, the first goal is to investigate the residual tensile properties of different types of HSRS and normal rebars including ASTM A706, A615, A1035CS, and A1035CM with grades of 420, 550, and 690 before and after high temperatures (350 °C and 700 °C), that simulates residual capacity after different levels of fire exposure. The second goal is to explore the residual bond strength of these rebars using both pull-out and end-beam tests after heat exposure, facilitating a comparison among test methods and evaluating their reliability under fire hazard conditions. The tensile test results indicated insignificant changes in the mechanical properties of all rebars after 350 ℃ heat exposure. However, there was a significant reduction of more than 30% in both yield and ultimate strength after 700 ℃ heat exposure for high grades like grade 690 of ASTM A1035. Among all rebar types and grades, only grade 420 of ASTM A706 retained most of its ductility and strength, making it the most reliable rebar among those tested against fire hazards. In the bond tests, splitting failure was observed at both ambient and after 500 °C heat exposure. Heat exposure resulted in a 73% reduction in bond strength across all rebars for the pull-out tests, with no significant variations between rebar types. On the other hand, end-beam tests indicated a 12.6% average reduction in bond strength with a 9% improvement in bond behavior for ASTM A706 grade 420. However, for ASTM A1035 CS grade 690 and ASTM A706 grade 550 there were slight reductions in bond behavior, with decreases of 9% and 14%, respectively. Compared to the end-beam test, the pull-out test results in a significant reduction in bond strength due to its high dependency on excessive compressive strength reduction resulting in brittle splitting failure. Based on comparison with empirical models, it is recommended not to use models derived from pull-out tests to estimate bond strength, as they tend to overestimate it. Instead, empirical models based on end-beam tests are recommended, since they show consistency with test results. It should be noted that although the bond strength based on splitting failure is primarily dependent on concrete properties, changes were observed in the bond behavior among different rebars, which can be attributed to changes in friction at the interface due to morphological changes in the rebar surface after heat exposure, as well as potential variations in thermal expansion properties, which need further research.

Effects of Hugoniot properties on jet onset conditions

Jets are the earliest ejected material from a hypervelocity impact event. Jets comprises of projectile and target's surface material and are ejected at velocities higher than escape velocity for Earth. Effects of Hugoniot properties of the projectile and target material on jet initiation are not well understood. We, therefore, developed a mathematical model that incorporated the limitations imposed by Hugoniot properties on jet initiation for hypervelocity impact. This model analysed the effects of changes in Hugoniot properties of the projectile and target on the jet onset time, jet onset velocity and jetting side (projectile or target). The results reveal that (i) jet initiates earlier and at higher velocity if the jetting side has higher value of shock parameter or higher velocity of sound in the material; (ii) jet initiates later and at lower velocity if jetting side has high density; (iii) effect of s-parameter and speed of sound in material is more profound than the effect of density.

Auditory prediction errors in sound frequency and duration generated different cortical activation patterns in the human brain: an ECoG study.

Sound frequency and duration are essential auditory components. The brain perceives deviations from the preceding sound context as prediction errors, allowing efficient reactions to the environment. Additionally, prediction error response to duration change is reduced in the initial stages of psychotic disorders. To compare the spatiotemporal profiles of responses to prediction errors, we conducted a human electrocorticography study with special attention to high gamma power in 13 participants who completed both frequency and duration oddball tasks. Remarkable activation in the bilateral superior temporal gyri in both the frequency and duration oddball tasks were observed, suggesting their association with prediction errors. However, the response to deviant stimuli in duration oddball task exhibited a second peak, which resulted in a bimodal response. Furthermore, deviant stimuli in frequency oddball task elicited a significant response in the inferior frontal gyrus that was not observed in duration oddball task. These spatiotemporal differences within the Parasylvian cortical network could account for our efficient reactions to changes in sound properties. The findings of this study may contribute to unveiling auditory processing and elucidating the pathophysiology of psychiatric disorders.

Substantially low thermal conductivity and high thermoelectric figure-of-merit in Bi-doped Sr2CoRuO6 double perovskites

Transition metal oxide thermoelectric materials are interesting due to their high thermal stability, low toxicity, and low cost. Although several interesting thermoelectric oxides have been reported thus far, but reducing the lattice thermal conductivity while maintaining the good electrical conductivity to get optimum thermoelectric performance is still a challenge. In addition, many oxide systems are not well explored as yet for their potential to convert waste heat into electricity using the Seebeck effect. Herein, we report the structural and thermoelectric properties of the Sr2−xBixCoRuO6 (0 ≤ x ≤ 0.8) double perovskites. Rietveld refinement of X-ray powder diffraction data shows that the unit cell parameters increase with Bi content (x). The electrical resistivity decreases with x due to the much larger and well-connected grains in Bi containing samples. The Seebeck coefficient changes its sign from negative to positive with increasing Bi content indicating hole doping. The thermal conductivity of the samples decreases with increasing x due to the soft chemical bonding and heavy atomic mass of the doped Bi atoms. These changes in transport properties lead to a large power factor of 1.87 × 10–4 W/m·K2 and a thermoelectric figure-of-merit of 0.24 for the x = 0.8 sample at 668 K. We estimated the heat capacities from the temperature independent Dulong-Petit limit for solids for calculation of the thermal conductivities and therefore some uncertainty in the reported zT values is expected.