Cumulative Impact of Micropolar Fluid and Porosity on MHD Channel Flow: A Numerical Study

The mass and heat transfer magnetohydrodynamic (MHD) flows have a substantial use in heat exchangers, electromagnetic casting, X-rays, the cooling of nuclear reactors, mass transportation, magnetic drug treatment, energy systems, fiber coating, etc. The present work numerically explores the mass and heat transportation flow of MHD micropolar fluid with the consideration of a chemical reaction. The flow is taken between the walls of a permeable channel. The quasi-linearization technique is utilized to solve the complex dynamical coupled and nonlinear differential equations. The consequences of the preeminent parameters are portrayed via graphs and tables. A tabular and graphical comparison evidently reveals a correlation of our results with the existing ones. A strong deceleration is found in the concentration due to the effect of a chemical reaction. Furthermore, the impact of the magnetic field force is to devaluate the mass and heat transfer rates not only at the lower but at the upper channel walls, likewise.

RASE: Modeling cumulative disadvantage due to marginalized group status in academia

We propose a framework of Resources, Achievement, Status, and Events (RASE) that allows the many disparate but well-documented phenomena affecting underrepresented groups in STEM to be assembled into a story of career trajectories, illuminating the possible cumulative impact of many small inequities. Our framework contains a three-component deterministic cycle of (1) production of Achievements from Resources, (2) updated community Status due to Achievements, and (3) accrual of additional Resources based on community Status. A fourth component, stochastic Events, can influence an individual’s level of Resources or Achievements at each time step of the cycle. We build a specific mathematical model within the RASE framework and use it to investigate the impact of accumulated disadvantages from multiple compounding variables. We demonstrate that the model can reproduce data of observed disparities in academia. Finally, we use a publicly available visualization and networking tool to provide a sandbox for exploring career outcomes within the model. The modeling exercise, results, and visualization tool may be useful in the context of training STEM faculty to recognize and reduce effects of bias.

Study of the Damage Evolution of Concrete with Different Initial Defect Rates under Uniaxial Compression with Acoustic Emission Technology

It is important to evaluate the internal damage of concrete under load conditions in order to evaluate its stability and usability for building applications. In this study, the uniaxial compression of concrete with initial defect was performed, and the internal damage of concrete was monitored by acoustic emission(AE) technology in real time to study the damage process and mechanism. The mechanical properties of concrete specimens with different initial defect were determined, and the cumulative impact count of AE was recorded. The response characteristics of AE in the process of concrete compression and damage were obtained. According to the analysis of the influence of the initial defect on the Kaiser effect and since the irreversibility of the AE process is related to the degree of damage caused by the material under the pre-load, it was determined that the initial defect will aggravate the damage inside the concrete under the same load level. Based on the statistics and analysis of the Weibull cumulative function, the correlation between AE parameters and damage variables was discussed.

The Ups and Downs of Being Us: Cross-Relationship Comparisons in Daily Life

Cross-relationship comparisons are an integral part of relationship processes, yet little is known about the impact of these comparisons in daily life. The present research employed a dyadic experience-sampling methodology ( N = 78 couples) with end-of-day surveys, end-of-week follow-up, and a 6-month follow-up to examine how individuals make cross-relationship comparisons in daily life, the cumulative impact of these comparisons over time, and the dyadic consequences of such comparisons. Participants made more downward than upward comparisons; however, upward comparisons had a more lasting impact, resulting in decreased satisfaction and optimism, and less positive self-perceptions and partner perceptions, at the end of each day and the week. Individuals who made more upward comparisons were also less satisfied 6 months later. Individuals were also affected by their partner’s comparisons: On days when partners made more upward comparisons, they felt less satisfied and optimistic about their relationship and less positive about themselves and their partner.

Tipping Points in the Earth System

There is mounting evidence that some parts of the Earth system may be at risk of abrupt and potentially irreversible changes, driven by the cumulative impact of incremental global warming. Such a non-linear transition could be triggered if a critical threshold in global temperature – a “tipping point” – is crossed, when a small change could push a system into a completely new state, with potentially catastrophic impacts. In this technical briefing, we will first define tipping points and tipping elements, then explore several tipping elements in more detail and discuss the questions of abruptness, irreversibility, timescales and uncertainties for each of them. We also investigate the possibility of developing early warning systems for tipping points, and the risk of cascades of interacting tipping points, where one tipping point could trigger another.

Quantitative Policy Analysis for Sustainable Aviation Fuel Production Technologies

This paper quantifies the impact of different policy options on the economic viability of sustainable aviation fuel (SAF) production technologies. The pathways considered include isobutanol to jet from corn grain, hydroprocessed esters and fatty acids (HEFA) from inedible fats and oils, HEFA from palm fatty acid distillate, synthesized iso-paraffins from sugarcane, Fischer-Tropsch (FT) gasification and synthesis from municipal solid waste, and micro FT from wood residues. The policies considered include feedstock subsidies, capital grants, output based incentives, and two policies intended to reduce project risk. Stochastic techno-economic analysis models are used to quantify the policies’ impact on project net present value and minimum selling price of the middle distillate fuel products. None of the technology pathways studied are found to be financially viable without policy aid. The median total policy costs required for economic viability range from 35 to 337 million USD per production facility, or 0.07–0.71 USD/liter. Our results indicate that the cumulative impact of multiple policies, similar in magnitude to analogous real-world fuel policies, could result in economically viable SAF production.

Constitutive deficiency of the neurogenic hippocampal modulator AP2γ promotes anxiety-like behavior and cumulative memory deficits in mice from juvenile to adult periods

The transcription factor activating protein two gamma (AP2γ) is an important regulator of neurogenesis both during embryonic development as well as in the postnatal brain, but its role for neurophysiology and behavior at distinct postnatal periods is still unclear. In this work, we explored the neurogenic, behavioral, and functional impact of a constitutive and heterozygous AP2γ deletion in mice from early postnatal development until adulthood. AP2γ deficiency promotes downregulation of hippocampal glutamatergic neurogenesis, altering the ontogeny of emotional and memory behaviors associated with hippocampus formation. The impairments induced by AP2γ constitutive deletion since early development leads to an anxious-like phenotype and memory impairments as early as the juvenile phase. These behavioral impairments either persist from the juvenile phase to adulthood or emerge in adult mice with deficits in behavioral flexibility and object location recognition. Collectively, we observed a progressive and cumulative impact of constitutive AP2γ deficiency on the hippocampal glutamatergic neurogenic process, as well as alterations on limbic-cortical connectivity, together with functional behavioral impairments. The results herein presented demonstrate the modulatory role exerted by the AP2γ transcription factor and the relevance of hippocampal neurogenesis in the development of emotional states and memory processes.

Distance sampling surveys reveal 17 million vertebrates directly killed by the 2020’s wildfires in the Pantanal, Brazil

Anthropogenic factors have significantly influenced the frequency, duration, and intensity of meteorological drought in many regions of the globe, and the increased frequency of wildfires is among the most visible consequences of human-induced climate change. Despite the fire role in determining biodiversity outcomes in different ecosystems, wildfires can cause negative impacts on wildlife. We conducted ground surveys along line transects to estimate the first-order impact of the 2020 wildfires on vertebrates in the Pantanal wetland, Brazil. We adopted the distance sampling technique to estimate the densities and the number of dead vertebrates in the 39,030 square kilometers affected by fire. Our estimates indicate that at least 16.952 million vertebrates were killed immediately by the fires in the Pantanal, demonstrating the impact of such an event in wet savanna ecosystems. The Pantanal case also reminds us that the cumulative impact of widespread burning would be catastrophic, as fire recurrence may lead to the impoverishment of ecosystems and the disruption of their functioning. To overcome this unsustainable scenario, it is necessary to establish proper biomass fuel management to avoid cumulative impacts caused by fire over biodiversity and ecosystem services.

Race Differences in Allostatic Load Among Black and White Men: Does Age Matter?

Although Black-White disparities in health and mortality among men persist, there has been a paucity of work focusing on race differences in physiological dysregulation of biological processes resulting from the cumulative impact of stressors among men. The purpose of this study was to assess potential race differences in Allostatic Load (AL) among adult men and if such differences varied by age. Data were drawn from the 1999-2016 NHANES and the study population included 21,529 non-Hispanic Black (NHB) and 34,282 Non-Hispanic White (NHW) born in US. Adjusting for potential confounders, NHB men 25-44 and 45-64 had a higher AL score (OR = 1.19, 95% confidence interval (CI) 1.00, 1.42) and (OR = 1.14, 95% confidence interval (CI) 1.02, 1.28) NHW men. No race differences with respect to AL score were observed among the other age groups. The results suggest that age plays a role in race differences in AL

Experimental Study on the Impact Resistance of Closed-Cell Aluminum Foam Protective Materials to RC Piers under Lateral Impact

In this study, the lateral impact tests of six RC piers which were protected by closed-cell aluminum foam (CCAF) were carried out by making use of an ultrahigh drop hammer horizontal impact test system. The protective effects of CCAF with different densities on the piers were then analyzed. The data regarding the piers’ impact force, displacement, reinforcement strain, and crack and damage development were mainly collected during the experimental testing processes. The results indicated that, when the impact energy was less than 7258 J and the density of the CCAF was 0.45 g/cm3, the cumulative impact force and displacements of the piers decreased by 67% and 35%, respectively. Therefore, it was considered that the CCAF with a density of 0.45 g/cm3 had displayed the best protective effects at that stage. It was also observed that when the impact energy was greater than 7258 J and the density of the CCAF was 0.55 g/cm3, the cumulative impact force and displacements of the piers decreased by 25% and 18%, respectively. Therefore, the CCAF with a density of 0.55 g/cm3 had displayed the best protective effects at that stage. Furthermore, under the conditions of constant accumulative impact energy, the protective effects of CCAF on the piers were observed to be weakened if it entered the densification stage too early and high-yield platforms were formed due to the density levels becoming too high. However, it was found that reasonable density and thickness increases could effectively delay the entry of CCAF into the densification stage, which effectively reduced the shearing effects which occurred when the impact speeds were too high, thereby preventing the shear failure of the piers.