Similar Behavior Research Articles

Propagation of random excitations in the polar representation of strongly nonlinear four-wave systems of turbulence.

The present work is concerned with the uncertainty propagation of the wave turbulent system. In particular, we study the temporal development and long-term behavior of the probability with respect to the amplitude and phase of complex-valued waves constituting the generic four-wave system of turbulence. Our approach to approximating the target distribution function is via the three steps: (i) to grasp the physical process described by the true turbulence model as random process, (ii) to determine the stochastic differential equation whose solution exhibits statistically similar behavior with the underlying turbulent signal, and (iii) to solve the corresponding Kolmogorov forward equation. Our implementation of the methodology is distinguished by employing a number of simplified stochastic models and applying one of them in the adaptive fashion which varies subject to the different parameter regime of the true dynamical system model. Accordingly, we become able to demonstrate the effectiveness of this reduced-order modeling framework for the analysis of the turbulent system characterized by not only weak but strong interactions among the nonlinear waves. We numerically corroborate our theoretical predictions in the context of the generalized Majda-Mclaughlin-Tabak wave turbulence prototype.

Elucidating the microscopic origin of observed anti-correlation between the protein-protein and protein-water interaction energies

Water as a solvent plays an important role in dictating the structure and dynamics of the large biomolecules like proteins. It has been proposed that the protein dynamics and energetics are closely coupled to the water molecules in the hydration shell. In particular, it has been shown earlier that the fluctuations in intra-protein (protein-protein) interaction energy is strongly anti-correlated with the protein-water interaction energy (solvation energy). Moreover, the dynamical signatures of water gets reflected into the protein dynamics in terms of a dominant power law behavior. In this work, we have carried out systematic molecular dynamics (MD) simulations of three different protein systems to understand the key physical factors that contribute to such anti-correlations. First, we compare the dynamics in globular folded proteins like Lysozyme with intrinsically disordered peptides (IDPs) like Amyloid beta to show that enhanced conformational fluctuations lead to significantly stronger anti-correlation. Trp-cage miniprotein shows a similar behavior distributed over two sub-ensembles of folded and unfolded states. We also investigate what type of interactions and molecular processes are responsible for the observed anti-correlation. In particular, we observe that the extent of correlation decreases significantly in the order of charged, polar and non-polar amino acid residues. Charged residues that form salt bridge interactions show a dominant anti-correlation. Surprisingly, a few non-polar (hydrophobic and buried) residues demonstrate significant anti-correlation as well. We attribute this to the structural fluctuations that lead to an equilibrium between buried and solvent exposed states of these residues, where the protein-protein and protein-water interactions compensate each other. Our studies indicate that the molecular origin of the observed anti-correlation can be vary depending on the type of the interaction. The overall coupling/correlation is dominated by the electrostatic interactions and charged residues due to a general dielectric screening effect, whereas a few buried hydrophobic residues may also show such coupling due to structural dynamics between buried and exposed states.

Psychometric Validation of the “LGBTIQ+ Themes in Literature Education” Scale (LTiLE)*

ABSTRACT The aim of this research is to describe the adaptation process and psychometric properties of the “LGBTIQ+ Themes in Literature Education” (LTiLE) scale, the first instrument aimed at measuring attitudes toward the inclusion of LGBTIQ+ content in the teaching interventions of future literature educators. The study seeks to identify empirical evidence of content, construct, convergent, and discriminant validity, as well as internal consistency reliability, and the absence of bias in assessments based on participants’ gender identity. Following the attainment of a high level of significant agreement on the quality of its content, an Exploratory Factor Analysis and Confirmatory Factor Analysis were conducted using a random sample of 592 Spanish recent graduates from programs related to Primary and Secondary Education teacher training. Both discriminant and convergent validity estimates yielded optimal results. Nomological validity was established through gender-based score comparisons, revealing significantly more favorable scores for cisgender women and other gender identities. A similar differential item behavior based on gender and measurement invariance according to the teaching stage were observed. Internal consistency was evaluated using ordinal α, McDonald’s ω, composite reliability, and complementarily, Cronbach’s. Psychometric evidence confirms LTiLE’s validity, reliability for prospective literature educators in non-university education.

Investigating performance metrics for container-based HPC environments using x86 and OpenPOWER systems

Container-based High-Performance Computing (HPC) is changing the way computation is performed and reproduced without sacrificing the raw performance compared to hypervisor-assisted virtualization technologies. It primarily supports continuously evolving data-intensive applications such as computational fluid dynamics, seismic tomography, molecular biology, and Proteomics. OpenPOWER systems, unlike the x86 systems, use the POWER-compliant processor to exploit instruction-level and thread-level parallelism heavily. In our previous work, we designed and developed a Containerized HPC environment (cHPCe) from the scratch using Linux namespaces on OpenPOWER systems. This paper aims to provide an in-depth performance analysis of the Containerized HPC environment using x86 systems and Containerized HPC environment using the OpenPOWER system, on systems’ subcomponents, processor, memory, interconnect, and IO. This sub-component analysis provides an insight on several aspects of the system performance. To the best of our knowledge, no research has been reported yet for such a comparative analysis that designs cHPCe for both x86 and OpenPOWER systems. The performance of the developed cHPCe is compared with BareMetals, and VMs using the benchmarks HPCC, and IOZone. Our experimental results achieve 0.13% less compute performance penalty at its peak performance on cHPCe compared to the BareMetal-based solution for x86 systems. In contrast, a VM-based solution introduces an overhead of 20% and 4.83% in x86 and OpenPOWER cases, respectively. Moreover, the x86 and OpenPOWER systems observe inconsistent behavior for memory performance with a worst-case penalty of 9.68% and 6.64% compared to achieved peak performance, respectively. However, similar behavior is reported for cHPCe with an overhead of less than 3% and 2% in the worst case for the latency and bandwidth, respectively, compared to the BareMetal for network and disk performance. Our experimental results reveal that the containerized OpenPOWER environment represents a viable alternative to the counterpart x86 environment for the HPC solution.

Cellular Chaos: Statistically Self-Similar Structures Based on Chaos Game

Abstract We present a novel methodology to generate mechanical structures based on fractal geometry using the chaos game, which generates self-similar point-sets within a polygon. Using the Voronoi decomposition of these points, we are able to generate groups of self-similar structures that can be related back to their chaos game parameters, namely, the polygonal domain, fractional distance, and number of samples. Our approach explores the use of forward design of generative structures, which in some cases can be easier to use for designing than inverse generative design techniques. To this end, the central hypothesis of our work is that structures generated using the chaos game can generate families of self-similar structures that, while not identical, exhibit similar mechanical behavior in a statistical sense. We present a systematic study of these self-similar structures through modal analysis and tensile loading and demonstrate a preliminary confirmation of our hypothesis.

The Physicochemical Properties and Melting Behavior of Ice Cream Fortified with Multimineral Preparation from Red Algae.

Ice cream is a popular frozen food consumed worldwide throughout the year. However, as a thermally unstable product, it requires proper cold chain management. Thermal fluctuations alter the physicochemical properties of ice cream and reduce its quality. This study was conducted to evaluate the physicochemical and sensory properties of ice cream containing different amounts (0.5; 0.8; 1.0%) of a multimineral preparation from Atlantic red algae. The effect of thermal shock on the quality of ice cream after preparation and 90 days of frozen storage was studied. The addition of a multimineral component slightly increased the freezing and glass transition temperatures of the ice cream. The overrun of the ice cream ranged from 48.55 to 52.78% and decreased with the frozen storage time, but the samples with 0.8 and 1.0% mineral content had the most stable overrun in terms of storage time and thermal fluctuations. Ice cream stored for both 7 and 90 days showed a similar melting behavior, although a shift in the melting curves was observed after long frozen storage. The samples exposed to the thermal treatment had lower melting rates by 39.2-59.9% and 55.2-65.4% for 7-day and 90-day stored ice cream, respectively. The hardness parameters of the ice cream did not change significantly under the conditions applied, so the fragility of the ice cream and its fluffiness did not seem to be affected. The organoleptic evaluation showed that ice cream with a mineral content of 0.8% was the most acceptable in terms of taste, texture, and overall acceptability. The applied mineral and sucrose content ratios did not alter the main physicochemical and organoleptic parameters, but significantly affected the nutrient density of the ice cream.

Characterization of the Reversible Intersystem Crossing Dynamics of Organic Photocatalysts Using Transient Absorption Spectroscopy and Time-Resolved Fluorescence Spectroscopy.

Thermally activated delayed fluorescence (TADF) emitters are molecules of interest as homogeneous organic photocatalysts (OPCs) for photoredox chemistry. Here, three classes of OPC candidates are studied in dichloromethane (DCM) or N,N-dimethylformamide (DMF) solutions, using transient absorption spectroscopy and time-resolved fluorescence spectroscopy. These OPCs are benzophenones with either carbazole (2Cz-BP and 2tCz-BP) or phenoxazine/phenothiazine (2PXZ-BP and 2PTZ-BP) appended groups and the dicyanobenzene derivative 4DP-IPN. Dual lifetimes of the S1 state populations are observed, consistent with reverse intersystem crossing (RISC) and TADF emission. Example fluorescence lifetimes in DCM are (5.18 ± 0.01) ns and (6.22 ± 1.27) μs for 2Cz-BP, (1.38 ± 0.01) ns and (0.32 ± 0.01) μs for 2PXZ-BP, and (2.97 ± 0.01) ns and (62.0 ± 5.8) μs for 4DP-IPN. From ground state bleach recoveries and time-correlated single photon counting measurements, triplet quantum yields in DCM are estimated to be 0.62 ± 0.16, 0.04 ± 0.01, and 0.83 ± 0.02 for 2Cz-BP, 2PXZ-BP, and 4DP-IPN, respectively. 4DP-IPN displays similar photophysical behavior to the previously studied OPC 4Cz-IPN. Independent of the choice of solvent, 4DP-IPN, 2Cz-BP, and 2tCz-BP are shown to be TADF emitters, whereas emission by 2PXZ-BP and 2PTZ-BP depends on the molecular environment, with TADF emission enhanced in aggregates compared to monomers. Behavior of this type is representative of aggregation-induced emission luminogens (AIEgens).

Application of the Euler–Lagrange Approach and Immersed Boundary Method to Investigate the Behavior of Rigid Particles in a Confined Flow

The presence of particles with a small but finite size, suspended in viscous fluids with low volumetric concentrations, is observed in many applications. The present study focuses on the tridimensional and incompressible lid-driven flow of Newtonian fluids through the application of the immersed boundary method and the Euler–Lagrange approach. These methods are used to numerically predict three-dimensional particle motion by considering nearly neutrally buoyant conditions as well as all relevant elementary processes (drag and lift forces, particle rotation, particle–wall interactions, and coupling between phases). Considering the current stage of the numerical platform, two coupling approaches between phases are considered: one-way and two-way coupling. A single particle is inserted in the cavity after steady-state conditions are achieved. Its three-dimensional motion is obtained from numerical simulations and compared with research data, considering the same conditions, evidently showing that the particle trajectory follows the experimental data until the first collision with a solid surface. After this first contact, there is a deviation between the results, with the two-way coupling results better representing the experimental data than the one-way coupling results. The dimensionless forces’ peaks acting on the particles are associated with the relative velocity of the particle near the wall–particle collision position. In terms of magnitude, in general, the drag force has shown greater influence on the particle’s motion, followed by the rotation-induced and shear-induced lift forces. Finally, a special application is presented, in which 4225 particles are released into the domain and their dynamic is evaluated throughout dimensionless time, showing similar behavior for both couplings between phases, with variations in local concentrations observed in certain regions. The mean square displacement used to quantify the dispersion evolution of the particles showed that the particulate flow reaches an approximately homogeneous distribution from the moment of dimensionless time tU/S = 130.

Genomic inbreeding measures applied to a population of mice divergently selected for birth weight environmental variance.

This study aimed to compare different inbreeding measures estimated from pedigree and molecular data from two divergent mouse lines selected for environmental birth weight during 26 generations. Furthermore, the performance of different approaches and both molecular and pedigree data sources for estimating Ne were tested in this population. A total of 1,699 individuals were genotyped using a high-density genotyping array. Genomic relationship matrices were used to calculate molecular inbreeding: Nejati-Javaremi (F NEJ), Li and Horvitz (F L&H), Van Raden method 1 (F VR1) and method 2 (F VR2), and Yang (F YAN). Inbreeding based on runs of homozygosity (F ROH) and pedigree inbreeding (F PED) were also computed. F ROH, F NEJ, and F L&H were also adjusted for their average values in the first generation of selection and named F ROH0, F NEJ0, and F L&H0. ∆F was calculated from pedigrees as the individual inbreeding rate between the individual and his parents (∆F PEDt) and individual increases in inbreeding (∆F PEDi). Moreover, individual ∆F was calculated from the different molecular inbreeding coefficients (∆F NEJ0, ∆F L&H, ∆F L&H0, ∆F VR1, ∆F VR2, ∆F YAN, and ∆F ROH0). The Ne was obtained from different ∆F, such as Ne PEDt, Ne PEDi, Ne NEJ0, Ne L&H, Ne L&H0, Ne VR1, Ne VR2, Ne YAN, and Ne ROH0. Comparing with F PED , F ROH , F NEJ and F VR2 overestimated inbreeding while F NEJ0 , F L&H , F L&H0 , F VR1 and F YAN underestimated inbreeding. Correlations between inbreeding coefficients and ∆F were calculated. F ROH had the highest correlation with F PED (0.89); F YAN had correlations >0.95 with all the other molecular inbreeding coefficients. Ne PEDi was more reliable than Ne PEDt and presented similar behaviour to Ne L&H0 and Ne NEJ0. Stable trends in Ne were not observed until the 10th generation. In the 10th generation Ne PEDi was 42.20, Ne L&H0 was 45.04 and Ne NEJ0 was 45.05 and in the last generation these Ne were 35.65, 35.94 and 35.93, respectively F ROH presented the highest correlation with F PED, which addresses the identity by descent probability (IBD). The evolution of Ne L&H0 and Ne NEJ0 was the most similar to that of Ne PEDi. Data from several generations was necessary to reach a stable trend for Ne, both with pedigree and molecular data. This population was useful to test different approaches to computing inbreeding coefficients and Ne using molecular and pedigree data.

Similarities and Differences between Nurses’ and Physicians’ Clinical Leadership Behaviours: A Quantitative Cross-Sectional Study

Background. Being a nurse or physician in today’s complex healthcare practice involves more than just responsibility for one aspect of care during one episode in a patient’s care trajectory. Both professionals are expected to take on a clinical leadership role and contribute positively to the reduction of care fragmentation and help in spanning professional boundaries. Although nurses may be well placed to identify the needs for integration, they may lack the position and status (compared to physicians) to address those needs as leaders. The aim of this study is to analyse similarities and differences between nurses and physicians in clinical leadership roles within a hospital context and explore how this relates to their interdisciplinary collaborative behaviours and perception on their job. Method. A cross-sectional survey among physicians and nurses was conducted to measure clinical leadership, job satisfaction, workload, and interdisciplinary collaborative behaviours. Results. Our results suggest that nurses (n = 329) and physicians (n = 100) show similar clinical leadership behaviours, based on equivalent scores on the clinical leadership scale. However, physicians score higher on the global leadership scale indicating they are more likely to perceive themselves as leaders than nurses. As clinical leaders, both nurses and physicians are more likely to express interdisciplinary collaborative behaviours. Furthermore, physicians who scored higher on the clinical leadership scale reported higher satisfaction with their job, whereas, for nurses, their score on the clinical leadership scale did not relate to their job satisfaction. Conclusion. As nurses in hospitals have the most frequent and direct involvement with patients, it seems inevitable for them to act as clinical leaders to promote patient-centred care. However, nurses less often perceived themselves as clinical leaders while showing suitable behaviours. Future studies should focus on the strategies nurses use to exert their clinical leadership, and for example, if nurses require the use of more dominant strategies to effect change.

Impact of the Toxic Dinoflagellate Alexandrium catenella on the Valve Movement of Mytilus edulis: A Comparison between Two Populations with Contrasting Histories Exposure

Shellfish aquaculture farms, due to their coastal position, face the threat of exposure to harmful algal blooms. Such blooms can release, among others, paralytic shellfish toxins (PST) produced by the dinoflagellate Alexandrium catenella and are known to cause the restriction of bivalve harvesting sites. Shellfish can accumulate PSTs in levels that are poisonous for humans, therefore making them unfit for consumption. Thus, the ability to detect PSTs before they reach the critical threshold is crucial for minimizing losses in the industry. Previous studies have demonstrated that toxic algae detection is possible with the use of an early warning system based on the valve-gaping behaviour of blue mussel Mytilus edulis. However, some studies observed the presence of toxin resistance in other species of bivalves when they are regularly exposed to PSTs. If no resistance is observed whatever the past history of the populations would be with regard to PST exposure, this species could be appropriate as a sentinel candidate. In this study, we compare the valve-gaping behaviour of two blue mussel populations with contrasting long-term histories of PSTs events (i.e., regularly vs. not previously exposed to the PSTs producer) were compared using experimental exposure of A. catenella to M. edulis. It was found that mussels from both populations exhibited similar gaping behaviour patterns when exposed to A. catenella. For both populations, the number of valve closures and closure duration tended to increase in the presence of A. catenella, which suggested an avoidance response to the toxic dinoflagellate. In conclusion, our results support the use of M. edulis without origin discrimination

Advanced Fanout Embedded Bridge Packaging Technology for Chiplets Integration

The increasing amount of data from all sectors driven by digital transformation is raising a problem of operational and storing cost of the data. Meanwhile, the exponential cost leaps of silicon scaling, the unfordable increasing of Si die size over reticle limit and unsustainable computer energy exceeding the world’s energy production have created an inflection point for semiconductor industry. It has driven the development of More-Than-Moore to augment increased device and system performance. Chiplets integration provides more flexible mix-and-match systems to accelerate performance and power efficiency. It is driving the development of advanced packaging technology to enable heterogeneous chiplets integration with separate designs and different manufacturing process nodes within a single package for yield improvement, IP reuse, performance and cost optimization, as well time to market reduction. Several advanced packaging technologies have been developed and used widely to integrate multi-chips with fine line/space interconnections, such as 2.5D Si TSV interposer, Fanout RDL (re-distribution layer) and EMIB (Embedded Multi-die Interconnect Bridge). Different packaging technologies have different sweet spots to fulfill various applications depending on the device design and performance requirements. In ASE, we have developed and introduced FOCoS (FanOut Chip on Substrate) chip first (FOCoS-CF) and FOCoS chip last (FOCoS-CL) technologies by using RDL interconnect for chiplets integration. However, due to the inherent fanout RDL process limitation, it has hit the bottleneck to manufacture RDL with higher layer counts (> 6 layers) and finer Line/Space (L/S < 1um/1um) for the applications that require high density die to die connections, high input/output (I/O) counts and high-speed signal transmitting. In this paper, a new FOCoS technology named as FOCoS embedded Si bridge (FOCoS-B) has been developed for high density die to die interconnect with RDL L/S < 1um/1um chipets integration for HPC application. The FOCoS-B packaging technology enables the USR (Ultra Short Reach) interconnection between die to die by embedded a small Si die in fanout RDL interposer. The small Si die play an interconnection bridge role between chiplets with L/S 0.8um/0.8um. Two FOCoS-B test vehicles (TVs) will be introduced in this study. One TV named as TV-1 is integrated by two chiplets of 1 ASIC die and 1 HBM2e with 1 Si bridge die to form a fanout module, which it is subsequently assembled on a FCBGA package with body size of 40x30mm2. Another TV listed as TV-2 is composed of two identical fanout modules, which are assembled on one FCBGA substrate with body size of 78x70mm2 in MCM (multi-chip-module) arrangement. The fanout module for TV-2 is integrated by 1 ASIC and 4 HBM2e with 4 bridge dies. TV-2 will have total 10 chiplets (2 ASICs and 8 HBM2e with 8 Si bridge dies). The process flow for FOCoS-B will be illuminated. The process DOE and the impact on warpage will be discussed. Furthermore, the reliability validations on two TVs will also be demonstrated. Finally, the comparison on warpage among different FOCoS solutions (FOCoS-B, FOCoS-CL and FOCoS-CL) for chiplets integration have been presented. The results indicated that the material selections and property compatibilities among the multi-layer stacked structures (Si die, RDL, Molding compounds, Underfill) play critical roles in warpage control in FOCoS-B processes. The package warpage of FOCoS-B and FOCoS-CL has showed similar behaviors. FOCoS-CF showed slightly high package warpage than that of FOCoS-B. The results also revealed that FOCoS-B has provided a wide choice and flexibility for multi bridge dies integration successfully for HPC application.

Detecting interference between applications and improving the scheduling using malleable application clones

This paper presents a novel feature for improving the scheduling process based on the performance prediction and the detection of CPU and I/O interference between applications. This feature consists of using malleable synthetic benchmarks – called clones – that reproduce the behaviour of applications executed in a cluster. These proxies can be used with two objectives: to build large and representative datasets that can be used to train the machine learning algorithms for modelling the platform workload, and to evaluate in advance if two executing applications can potentially produce contention hazards related to the shared use of the system resources like CPU, cache memory or I/O bandwidth. The proposed framework generates application clones based on generic-purpose performance information collected from monitoring. Unlike other works based on the use of micro-architectures or metrics obtained from simulators, in the approach presented in this work, the application clones generate similar behaviour without extracting data from the binaries, avoiding the necessity of managing code or data from the applications. One advantage of this approach is that they can be shared securely because they have not been generated using any piece of the original code. In addition, the proposed clones are malleable, so they also able to model the application behaviour under a different number of processes. In this work, we show how the use of clones contributes to improving the application scheduling by reducing the number of evaluations that is necessary to perform, and to detect performance degradation (interference) without the necessity of involving the execution of the actual applications. We evaluate the proposed clone generation approach on two sets of benchmarks (CPU and I/O oriented) and several applications. We also compare the performance obtained during the execution of the proxies and the applications to show their similarity. Finally, we include an evaluation of the interference detection using this novel approach.

Impact of the Nares Strait sea ice arches on the long-term stability of the Petermann Glacier ice shelf

Abstract. One of the last remaining floating tongues of the Greenland ice sheet (GrIS), the Petermann Glacier ice shelf (PGIS), is seasonally shielded from warm Atlantic water (AW) by the formation of sea ice arches in the Nares Strait. However, continued decline of the Arctic sea ice extent and thickness suggests that arch formation is likely to become anomalous, necessitating an investigation into the response of PGIS to a year-round mobile and thin sea ice cover. We use a high-resolution unstructured grid 3-D ocean–sea ice–ice shelf setup, featuring an improved sub-ice-shelf bathymetry and a realistic PGIS geometry, to investigate in unprecedented detail the implications of transitions in the Nares Strait sea ice regime, that is, from a thick and landfast sea ice regime to a mobile, and further, a thin and mobile sea ice regime, with regard to PGIS basal melt. In all three sea ice regimes, basal melt near the grounding line (GL) presents a seasonal increase during summer, driven by a higher thermal driving. The stronger melt overturning increases the friction velocity slightly downstream, where enhanced friction-driven turbulent mixing further increases the thermal driving, substantially increasing the local melt. As the sea ice cover becomes mobile and thin, wind and (additionally in winter) convectively upwelled AW from the Nares Strait enter the PGIS cavity. While its effect on basal melting is largely limited to the shallower (<200 m) drafts during winter, in summer it extends to the GL (ca. 600 m) depth. In the absence of an increase in thermal driving, increased melting under the deeper (>200 m) drafts in winter is solely driven by the increased vertical shear of a more energetic boundary layer current. A similar behaviour is noted when transitioning from a mobile to a thin mobile sea ice cover in summer, when increases in thermal driving are negligible and increases in melt are congruent with increases in friction velocity. These results suggest that the projected continuation of the warming of the Arctic Ocean until the end of the 21st century and the accompanying decline in the Arctic sea ice extent and thickness will amplify the basal melt of PGIS, impacting the long-term stability of the Petermann Glacier and its contribution to the future GrIS mass loss and sea level rise.

Thickness-dependent variations of atomic vibration, band-edge excitonic emission, and valleytronic response in layered Mo0.55W0.45S2 ternary compounds

Two-dimensional (2D) van der Waals transition metal dichalcogenides (TMDs) are highly attractive due to their novel phenomena and potential device applications, but most of the studies are focused on binary TMDs except a few reports on ternary TMDs. Here, we report thickness-dependent mono-to-multi-layer transition behaviors of mechanically-exfoliated ternary TMD Mo0.55W0.45S2. Dependences of Raman modes and their peak intervals on thickness (d) are divided into three regions (1.5 ≤ d ≤ 9.2, 9.2 < d ≤ 34, and > 34 nm), mostly resulting from the increase of van der Waals force and long-range Coulomb force in interlayer interactions at larger d. Photoluminescence (PL) peak and its intensity/full width at half maximum show similar three-region behaviors, which are associated with direct-to-indirect-bandgap transition as d increases. In particular, critical changes in the Raman scattering and PL occur at d = 9.2 nm (8–13 layers), meaning a 2D-to-3D transition. The effect of the valley polarization is observed up to d = 8.1 nm (7–11 layers), resulting from random mixing-induced suppression of the inversion symmetry in the multilayer. These results suggest that the critical layer number for the 2D-to-3D dimensional crossover in ternary Mo0.55W0.45S2 is considerably larger than in binary TMDs, thereby exhibiting the direct-bandgap nature in an extended range of layer number, more useful for their optoelectronic device applications.

High-temperature oxidation behavior of laser additively manufactured AlCrCoNiSi-based high-entropy alloys at 1100 ℃

High-temperature oxidation behavior of two laser additively manufactured AlCrCoNiSi-based high-entropy alloys (Al10 and Al15) are systematically studied in this work. These two alloys exhibit similar oxidation behaviors involving initial linear kinetics oxidation and subsequent parabolic kinetics oxidation at 1100 ℃. However, Al10 alloy has a superior oxidation resistance than Al15 alloy according to the oxidation rate constant. α-Al2O3 is the predominant phase of the oxide scales grown on both alloys. Cross-sectional views of the scales show that the scales consist of surface equiaxed grains and underlying columnar grains. For all oxidized alloys, a newly-formed fcc layer forms in the subsurface Al-depletion zone due to the preferential oxidation of aluminum. Al10 alloy exhibits a much thicker newly-formed fcc layer than Al15 alloy after the same oxidation time. This work ascribes the superior oxidation resistance of Al10 alloy to its thick newly-formed fcc layer, which suppresses the outward Al diffusion from the substrate to scale-metal interface by increasing the diffusion distance.

Effects of complete slip conditions on the peristaltic pumping of a Casson nanofluid with suction and injection in a vertical channel

This study investigates the effects of complete slip conditions on the peristaltic pumping of a Casson nanofluid with suction and injection in a vertical due to the crucial role that nano liquids play in a variety of technological and medical fields, particularly in peristalsis, a mechanism that transports liquids. The Casson fluid belongs to a class of non-Newtonian fluids that, through a particular stress threshold magnitude, exhibit elastic solid behavior before changing to liquid behavior. These fluids have several uses in engineering, food preparation, drilling and other fields. After establishing the governing conservation equations, the resulting flow model is effectively simulated using the realistic assumptions of a long wavelength and a low Reynolds number. The temperature distributions, velocity, pressure rate per wavelength and nanoparticle concentration of the resulting flow problem have been solved analytically. The effects of all physical factors on temperature, velocity, concentration fields, pressure rate, frictional force and pressure gradient are graphically examined using Wolfram MATHEMATICA software. There are a variety of biofluids that cannot be classified as liquids. For example, blood contains WBC, RBC and plasma. It is essential to model biofluids (blood) as nanofluids given the physical properties of these biofluids. According to reports, one of the finest yield stress models is the Casson model, and blood exhibits a similar behavior. We took these facts into consideration when thinking about Casson nanofluid flow in a vertical layer under peristalsis. Additionally, the suction and injection mechanisms can be used to represent the exchange of carbon dioxide in bold. In order to understand how blood flows through small blood vessels, this model must be examined. The obtained results show that the Newtonian case and those found in the literature have a very good agreement. Since the liquid moves faster and more effectively when the value is increased, it becomes clear that this increases the strength of the velocity. In other words, nanoperistaltic pumps can maintain a pressure differential that increases or decreases at all operating flow rates with an increasing thermophoresis effect. Furthermore, it is obvious that the pressure reduction in a Casson fluid is greater than in a Newtonian fluid.

Postural Stability When Grasping an Object While Standing: Younger and Older Adults (Fallers and Non-Fallers)

We investigated postural stability through the margin of stability (MoS) while reaching and grasping an object with increasing difficulty levels in younger, fallers and non-fallers. Forty-five individuals distributed into three groups participated in this study: younger adults (YA), non-fallers (OA), and fallers (FOA). They stood upright and reached and grasped a dowel. Six conditions combining the stability of the dowel’s base and obstacles close to the dowel were manipulated to characterize different difficulty levels. We computed the MoS in both anterior-posterior (AP) and medial-lateral (ML) directions in the interval between reaching onset and dowel contact. From the MoS time series, we analyzed the minimum and maximum, including the time of occurrence of these events. The MoS was smaller for OA than for YA in both directions. In the ML direction, the minimum MoS was smaller for FOA than for YA. The minimum MoS took place earlier for FOA than YA in the AP direction. FOA and OA exhibited similar behavior with reduced MoS, suggesting impaired postural control during reaching-to-grasping in a standing posture. FOA used a more cautious strategy by reverting the MoS earlier than YA, allowing them to increase their MoS before YA when preparing to grasp the dowel.

Prediction of Oxygen Distribution in Silos and Chambers Filled with Various Agricultural Commodities

In the context of post-harvest pest management in agricultural products, the adoption of modified atmospheres presents an eco-friendly alternative to conventional pesticides. This study focuses on nitrogen gas as a potential agent for insect control in stored commodities, utilizing computational simulations (by employing the convection–diffusion equation) to investigate its penetration and distribution within two common storage configurations: chamber-contained pallets and silos. The results highlight the influence of boundary conditions, commodity porosity, and convection effects on nitrogen dispersion. In chamber scenarios, the first boundary condition considers that pallets are placed inside a chamber with uniform (99.5%) nitrogen concentration, whereas in the second one, the concentration gradually increases from 78% to 99.5%. The average duration required for O2 concentration to reach 1% is approximately 10.7 h and 133.3 h for the two boundary conditions, respectively. Among the agricultural commodities, walnuts (kernels) exhibit the shortest duration, while prunes require the longest time. In silos, convection and diffusion interact to establish a consistent diffusion layer thickness. Most agricultural products exhibit similar behavior, with average times of 13.5 h, 25.4 h, and 37.0 h for three heights (10 m, 20 m, and at the silo’s top at 30 m), respectively.

Mechanical behavior analysis of polypropylene composites with waste PET felt fibers

AbstractThe utilization of plastic waste is another way to protect the ecology and reduce plastic pollution, which researchers and industries have been effectively focusing on for the last decade. Polyethylene terephthalate felt (PETf) is a packaging material abundantly utilized in the automotive sector and is released as waste, and its popularity as an industrial waste necessitates attention to proper disposal. Therefore, the current study utilized waste PETf as a reinforcement (5–15 wt%) for a polypropylene (PP) matrix using various molding approaches, in light of the higher aspect ratio of the fibers. In the first approach, the fibers were extracted from PETf through a mechanical process, and various percentages of PET felt fibers (PETff) were extruded with PP pellets, followed by injection molding. Second, PETf was directly laid on a PP sheet and processed by compression molding. The tensile strength, tensile modulus, and morphological and spectral properties of the fabricated composites were evaluated. Morphological and spectral analyses explain the distribution and interaction of the fibers in the PP matrix. The 10%PETff enhanced the tensile strength and modulus of PP by 37.3% and 52.15%, respectively. Conversely, the 1.5% malic anhydride‐g‐PP (MAPP)‐PP/PETf composites showed similar tensile behavior, with values of approximately 41.53 MPa and 1.6 GPa. In addition, the tensile strength significantly increased by 35.75% with the addition of MAPP. Overall, the current study demonstrates a well‐structured research design that effectively employs waste PETf as reinforcement for PP composites. The mechanical strength of these composites makes them highly versatile and renders them suitable for a wide range of applications, from automotive packaging to the manufacturing of high‐performance automotive components.Highlights Utilized waste PET as reinforcement for manufacturing of PP composite. PET and PP interacted in a self‐reinforcing manner. Injection and compression molding techniques used for PET/PP composites. Repurposing waste PET by compression molding is eco‐friendly practices. PET fibers significantly improved mechanical properties of PP composites.