Post-buckling and Large-deflection analysis of a sandwich FG plate with FG porous core using Carrera’s Unified Formulation

In this study, the unified formulation of a full geometrically nonlinear refined plate theory in a total Lagrangian approach is developed to study the post-buckling and large-deflection analysis of sandwich functionally graded (FG) plate with FG porous (FGP) core. The plate has three layers so that the upper and lower layers are FG and the middle layer (core) is the FGP, which is considered with four cases in terms of the porosity core distribution. The different two-dimensional (2D) plate structures kinematics are consistently implemented based on the Carrera’s Unified Formulation (CUF) by means of an index notation and an arbitrary expansion function of the generalized variables in the thickness direction, leading to lower- to higher-order plate models with only pure displacement variables. Furthermore, a finite element approximation and the principle of virtual work are used to easily and straightforwardly formulate the nonlinear governing equations in a total Lagrangian manner, whereas a path-following Newton-Raphson linearization scheme based on the arc-length constraint is utilized to solve the full geometrically nonlinear problem. Numerical assessments are finally conducted to confirm the capabilities of the proposed CUF plate model to predict the post-buckling and large-deflection equilibrium curves with high accurac

Hierarchy of piecewise non-linear maps with non-ergodicity behavior

We study the dynamics of hierarchy of piecewise maps generated by one-parameter families of trigonometric chaotic maps and one-parameter families of elliptic chaotic maps of $\mathbf{cn}$ and $\mathbf{sn}$ types, in detail. We calculate the Lyapunov exponent and Kolmogorov-Sinai entropy of the these maps with respect to control parameter. Non-ergodicity of these piecewise maps is proven analytically and investigated numerically . The invariant measure of these maps which are not equal to one or zero, appears to be characteristic of non-ergodicity behavior. A quantity of interest is the Kolmogorov-Sinai entropy, where for these maps are smaller than the sum of positive Lyapunov exponents and it confirms the non-ergodicity of the maps.Comment: 18 pages, 8 figure

Coupling of organic and inorganic aerosol systems and the effect on gas-particle partitioning in the southeastern US

Several models were used to describe the partitioning of ammonia, water, and organic compounds between the gas and particle phases for conditions in the southeastern US during summer 2013. Existing equilibrium models and frameworks were found to be sufficient, although additional improvements in terms of estimating pure-species vapor pressures are needed. Thermodynamic model predictions were consistent, to first order, with a molar ratio of ammonium to sulfate of approximately 1.6 to 1.8 (ratio of ammonium to 2  ×  sulfate, R_(N∕2S)  ≈  0.8 to 0.9) with approximately 70 % of total ammonia and ammonium (NH_x) in the particle. Southeastern Aerosol Research and Characterization Network (SEARCH) gas and aerosol and Southern Oxidant and Aerosol Study (SOAS) Monitor for AeRosols and Gases in Ambient air (MARGA) aerosol measurements were consistent with these conditions. CMAQv5.2 regional chemical transport model predictions did not reflect these conditions due to a factor of 3 overestimate of the nonvolatile cations. In addition, gas-phase ammonia was overestimated in the CMAQ model leading to an even lower fraction of total ammonia in the particle. Chemical Speciation Network (CSN) and aerosol mass spectrometer (AMS) measurements indicated less ammonium per sulfate than SEARCH and MARGA measurements and were inconsistent with thermodynamic model predictions. Organic compounds were predicted to be present to some extent in the same phase as inorganic constituents, modifying their activity and resulting in a decrease in [H^+]_(air) (H^+ in µg m^(−3) air), increase in ammonia partitioning to the gas phase, and increase in pH compared to complete organic vs. inorganic liquid–liquid phase separation. In addition, accounting for nonideal mixing modified the pH such that a fully interactive inorganic–organic system had a pH roughly 0.7 units higher than predicted using traditional methods (pH  =  1.5 vs. 0.7). Particle-phase interactions of organic and inorganic compounds were found to increase partitioning towards the particle phase (vs. gas phase) for highly oxygenated (O : C  ≥  0.6) compounds including several isoprene-derived tracers as well as levoglucosan but decrease particle-phase partitioning for low O : C, monoterpene-derived species

Air pollution perception in ten countries during the COVID-19 pandemic

As largely documented in the literature, the stark restrictions enforced worldwide in 2020 to curb the COVID-19 pandemic also curtailed the production of air pollutants to some extent. This study investigates the perception of the air pollution as assessed by individuals located in ten countries: Australia, Brazil, China, Ghana, India, Iran, Italy, Norway, South Africa and the USA. The perceptions towards air quality were evaluated by employing an online survey administered in May 2020. Participants (N = 9394) in the ten countries expressed their opinions according to a Likert-scale response. A reduction in pollutant concentration was clearly perceived, albeit to a different extent, by all populations. The survey participants located in India and Italy perceived the largest drop in the air pollution concentration; conversely, the smallest variation was perceived among Chinese and Norwegian respondents. Among all the demographic indicators considered, only gender proved to be statistically significant

Global prevalence of Trichinella in pigs: A systematic review and meta-analysis

Background: Investigating the global epidemiological patterns of Trichinella in pigs is required for accurate recognition and to establishing proper control programmes and preventivemeasures, as well as to decrease human exposure. Objectives: To obtain a better understanding of the global prevalence of Trichinella in domestic pigs and factors that might influence the prevalence, a systematic review and meta-analysis was performed. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Multiple databases were used to identify literature published between January 2000 and December 2021, representing studies from 1985 to 2021, on Trichinella prevalence in domestic pigs. Prevalence was calculated on a global and country level, by country Human Development Index (HDI), climate, pig management system, and diagnostic test. Results: The global pooled prevalence based on 60manuscripts representing 32 countries and 65 pig populations was 2.02% (95% confidence interval [CI]: 0.88–3.62) and the estimated pooled prevalence in different continents ranged from 0.00% to 11.8%. Trichinella was highest in low HDI countries (21.6%; 95% CI: 4.3–47.2), tropical wet climates (20.9%; 95% CI: 10.3–34.1), and non-intensive pig farming systems (6.1%; 95% CI: 1.0–15.5). Conclusions: While there were regional differences in Trichinella prevalence in domestic pigs, these were likely driven by country HDI and pig farming systems versus climatic factors. Increased biosecurity in outdoor pig production systems, focused meat inspections and promoting awareness could potentially decrease risk of infectio

Customized clinical practice guidelines for management of adult cataract in Iran

Purpose: To customize clinical practice guidelines (CPGs) for cataract management in the Iranian population. Methods: First, four CPGs (American Academy of Ophthalmology 2006 and 2011, Royal College of Ophthalmologists 2010, and Canadian Ophthalmological Society 2008) were selected from a number of available CPGs in the literature for cataract management. All recommendations of these guidelines, together with their references, were studied. Each recommendation was summarized in 4 tables. The first table showed the recommendation itself in clinical question components format along with its level of evidence. The second table contained structured abstracts of supporting articles related to the clinical question with their levels of evidence. The third table included the customized recommendation of the internal group respecting its clinical advantage, cost, and complications. In the fourth table, the internal group their recommendations from 1 to 9 based on the customizing capability of the recommendation (applicability, acceptability, external validity). Finally, customized recommendations were sent one month prior to a consensus session to faculty members of all universities across the country asking for their comments on recommendations. Results: The agreed recommendations were accepted as conclusive while those with no agreement were discussed at the consensus session. Finally, all customized recommendations were codified as 80 recommendations along with their sources and levels of evidence for the Iranian population. Conclusion: Customization of CPGs for management of adult cataract for the Iranian population seems to be useful for standardization of referral, diagnosis and treatment of patients. © 2015 Journal of Ophthalmic and Vision Research | Published by Wolters Kluwer - Medknow

Coupling of organic and inorganic aerosol systems and the effect on gas-particle partitioning in the southeastern US

Several models were used to describe the partitioning of ammonia, water, and organic compounds between the gas and particle phases for conditions in the southeastern US during summer 2013. Existing equilibrium models and frameworks were found to be sufficient, although additional improvements in terms of estimating pure-species vapor pressures are needed. Thermodynamic model predictions were consistent, to first order, with a molar ratio of ammonium to sulfate of approximately 1.6 to 1.8 (ratio of ammonium to 2  ×  sulfate, R_(N∕2S)  ≈  0.8 to 0.9) with approximately 70 % of total ammonia and ammonium (NH_x) in the particle. Southeastern Aerosol Research and Characterization Network (SEARCH) gas and aerosol and Southern Oxidant and Aerosol Study (SOAS) Monitor for AeRosols and Gases in Ambient air (MARGA) aerosol measurements were consistent with these conditions. CMAQv5.2 regional chemical transport model predictions did not reflect these conditions due to a factor of 3 overestimate of the nonvolatile cations. In addition, gas-phase ammonia was overestimated in the CMAQ model leading to an even lower fraction of total ammonia in the particle. Chemical Speciation Network (CSN) and aerosol mass spectrometer (AMS) measurements indicated less ammonium per sulfate than SEARCH and MARGA measurements and were inconsistent with thermodynamic model predictions. Organic compounds were predicted to be present to some extent in the same phase as inorganic constituents, modifying their activity and resulting in a decrease in [H^+]_(air) (H^+ in µg m^(−3) air), increase in ammonia partitioning to the gas phase, and increase in pH compared to complete organic vs. inorganic liquid–liquid phase separation. In addition, accounting for nonideal mixing modified the pH such that a fully interactive inorganic–organic system had a pH roughly 0.7 units higher than predicted using traditional methods (pH  =  1.5 vs. 0.7). Particle-phase interactions of organic and inorganic compounds were found to increase partitioning towards the particle phase (vs. gas phase) for highly oxygenated (O : C  ≥  0.6) compounds including several isoprene-derived tracers as well as levoglucosan but decrease particle-phase partitioning for low O : C, monoterpene-derived species