Droughts are large-scale perturbations that affect freshwater ecosystems worldwide. A water level reduction caused by drought is an important driving factor of phytoplankton dynamics. It has been ...suggested that a water level reduction alters the light and mixing regime and increases nutrient concentrations and phytoplankton biomass favoring cyanobacterial blooms. We took advantage of two exceptionally dry years in the Brazilian semi-arid region to investigate the effects of the water level reduction on the water quality and phytoplankton communities of two shallow man-made lakes. In both lakes, the water level was reduced by half, while the water turbidity, conductivity, and nutrient concentrations increased. In the deeper lake, the phytoplankton biomass increased and was dominated by a cyanobacteria group as expected, but it decreased in the shallower lake and was dominated by mixotrophic flagellate groups. This was because of sediment resuspension by wind and fish facilitated by a water level reduction and increased the water turbidity more strongly in the shallower than in the deeper lake. Therefore, a water level reduction caused by a drought may either increase or decrease the phytoplankton biomass and cyanobacteria dominance in tropical shallow lakes depending on the lake depth and the concentration of inorganic suspended sediments.
Healthcare optimization has become increasingly important in the current era, where numerous challenges are posed by population ageing phenomena and the demand for higher quality of the healthcare ...services. The implementation of Internet of Things (IoT) in the healthcare ecosystem has been one of the best solutions to address these challenges and therefore to prevent and diagnose possible health impairments in people. The remote monitoring of environmental parameters and how they can cause or mediate any disease, and the monitoring of human daily activities and physiological parameters are among the vast applications of IoT in healthcare, which has brought extensive attention of academia and industry. Assisted and smart tailored environments are possible with the implementation of such technologies that bring personal healthcare to any individual, while living in their preferred environments. In this paper we address several requirements for the development of such environments, namely the deployment of physiological signs monitoring systems, daily activity recognition techniques, as well as indoor air quality monitoring solutions. The machine learning methods that are most used in the literature for activity recognition and body motion analysis are also referred. Furthermore, the importance of physical and cognitive training of the elderly population through the implementation of exergames and immersive environments is also addressed.
•Phase transformation kinetics is measured by in-situ laser ultrasonics in Ti-5553.•The transformed fractions are linearly correlated to the changes in wave velocity.•An analytical model based on ...isotropic elasticity assumption describes the results.•Transformation model confirms different mechanisms as a function of temperature.•Results encourage broader use of laser ultrasonics to monitor microstructure evolution.
In this study, we explored the potential of laser ultrasonics for metallurgy (LUMet) as an advanced in-situ technique to measure the α formation kinetics during high temperature isothermal holdings of a Ti-5553 (Ti-5Al-5Mo-5V-3Cr, wt%) alloy. The measured changes in ultrasound velocity were seen to increase linearly with the α phase volume fraction in the investigated temperature range. Using the law of mixture an analytical model was developed to rationalize this experimental observation based on the temperature dependent macroscopic elastic constants and densities of the α and β phases. The transformation kinetics were modeled in the frame of the Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory and the JMAK exponents coincide with the sequence of precipitation observed. Further, a partial time-temperature-transformation (TTT) diagram, constructed from the LUMet data, was found to be consistent with results from in-situ electrical resistivity measurements reported for the same alloy. Considering the advantages of the real-time, non-contact and non-destructive nature of LUMet, this sensor technique provides an excellent monitoring capacity for tracking microstructure evolution in Ti-alloys.
The achievement of a healthy indoor environ- ment-an indispensable requirement for human well-being-relies on the establishment of good air quality conditions and thermal comfort levels. This study ...addresses the development of a healthcare-focused Internet-of-Things (IoT) system for the cardiac assessment using photoplethysmography (PPG) and ballistocardiography (BCG) that can be applied in any indoor environment. Results from its experimental application include the analysis of heart rate variability (HRV) and respiratory status from a group of young adults under different thermal conditions and relative humidity (RH) levels. The final goal was to investigate the effects of short-term exposure to different air temperature and humidity conditions on human thermal comfort based on the analysis of the autonomic nervous system (ANS) activity. The experiment took place in a regular and nonisothermal office environment. Simulations based on computational fluid dynamics (CFD) were conducted to estimate heat distribution and select the optimal locations for the environmental sensor nodes' placement. Results indicated that activation of the parasympathetic system was more notable in short-term exposures to environments with different air temperatures (24 °C-30 °C) than with different levels of RH (50%-70%). Changes in ambient air temperature led to the activation of thermal regulatory reflexes and thermal discomfort, perceived by an increase in the ratio of low frequency to high frequency (LF/HF) at higher air temperature exposures. In addition, HRV parameters were used to train machine learning models on predicting if the user is in a thermally comfortable environment or a discomfortable environment (hot or humid), having achieved an 87% average accuracy.
Dual-phase (DP) steels are advanced high-strength steels used in automotive design. To achieve optimal mechanical properties the control of phase transformations during processing is paramount, e.g. ...for hot-rolled DP steels a desired ferrite fraction is required to form during run-out table cooling. Thus, sensor technologies such as laser ultrasonics (LUS) are of considerable interest that can in-situ monitor ferrite formation. In this study, the ferrite formation kinetics in a laboratory DP steel were measured by LUS during stepped cooling treatments which were designed to simulate the cooling paths on the run-out table in hot strip mills. LUS measurements were first validated with well-established dilatometry measurements during continuous cooling. For the stepped cooling tests, the fractions transformed obtained from the ultrasonic velocity changes agree with the ferrite phase fractions as characterized by ex-situ metallography. Further, the velocity changes are described by the JMAK approach using parameters that are consistent for the austenite-to-ferrite transformation in low-carbon steels.
Mariana Rodrigues, nasceu em 1995, em Osasco, onde reside. Sua prática pictórica abstrata está ligada ao estudo de práticas corporais e ancestrais em que corpo mente e espírito são compreendidos como ...uma unidade. Essa percepção da lugar a uma materialização do inconsciente através de formas, cores e gestos que estão além de uma compreensão racional da realidade. Este ensaio é o conjunto dos trabalhos mais recentes da artista.
In philosophy of science, the literature on abduction and the literature on styles of thinking have existed almost totally in parallel. Here, for the first time, we bring them together and explore ...their mutual relevance. What is the consequence of the existence of several styles of scientific thinking for abduction? Can abduction, as a general creative mode of inference, have distinct characteristic forms within each style? To investigate this, firstly, we present the concept of abduction; secondly we analyze what is understood by styles of thinking; thirdly, we give some comments on abduction and styles of thinking by analyzing examples of scientific discovery or innovation within each style. We develop a case-based comparative investigation of creative aspects of abductive reasoning with examples drawn from different styles of scientific thinking and doing as understood by the Crombie/Hacking tradition. We argue that abduction, as a general mode of reasoning, can have a variety of specific expressions enabled and constrained by the styles of scientific thinking. Finally, we draw some conclusions on the relationship between abduction and styles of thinking suggesting that scientific discovery is a dynamical goal-directed activity within the scientific community that benefits from distinct styles of thinking and doing research.
When people indicate the vanishing location of a moving target that suddenly disappears, systematic errors forward (in the direction of motion) and downward (in the direction of gravity) emerge. ...These spatial displacements were coined, respectively, Representational Momentum and Representational Gravity, and are believed to reflect internalized ecologically relevant physical invariants useful for the anticipation of future states of an event. Previous research has shown that sports athletes exhibit increased Representational Momentum, indicating enhanced motion extrapolation and anticipation, albeit it is still not clear up to what degree this effect is specific for the expertise context or if it generalizes to other dynamic events. Furthermore, the influence of expertise on Representational Gravity, particularly in contexts where anticipation of vertically moving objects is crucial, remains understudied. This study aimed to address these gaps by focusing on Volleyball as a context of expertise due to the prevalence of fast vertically moving balls. Volleyball athletes and non-athletes indicated the perceived offset location of a smoothly moving target, which moved at a constant speed or was subjected to acceleration/deceleration, embedded either in a Volleyball or neutral context. Outcomes revealed that for the Volleyball context, athletes, but not non-athletes, revealed a significant trend to misperceive targets moving along the left diagonal to be further displaced forward beyond what would be expected due to Representational Momentum alone. This finding is discussed in relation to the natural statistics of Volleyball games, where crossed ball trajectories, particularly by the outside hitter, are more prevalent, fast, and offensive, requiring better anticipation to be efficiently dealt with.
Molybdenum (Mo) is one of the most common
β
-stabilizing elements used in commercial titanium alloys. In comparison with other traditional
β
-stabilizers, Mo possesses the lowest diffusion rate in ...the
β
phase and a rather low diffusivity in the
α
phase, therefore playing an important role in the
α
/
β
phase transformation rates. While most of the earlier studies focused on complex multi-component Ti-systems as well as highly alloyed binary Ti–Mo alloys, here we investigate quasi-binary Ti–Mo model alloys with systematically varied Mo content up to 6 wt pct, which is the relevant level for many commercial Ti-alloys. A Gleeble thermo-mechanical simulator coupled with a Laser Ultrasonics for Metallurgy (LUMet) sensor was used to measure the phase transformation rates in these alloys during continuous heating and cooling treatments at varying rates. The measurably different densities and elastic constants of the parent and product phases result in variation in the ultrasound longitudinal velocity, which is correlated to the transformed volume fractions. The rate of the thermal treatments was seen to have a larger effect on transformation rates during cooling, as compared to that on heating. Further, increasing the Mo content retards the phase transformations. The results obtained during continuous heating were compared with thermodynamic calculations, while those obtained during cooling were modeled using the additivity concept applied to the Johnson–Mehl–Avrami–Kolmogorov (JMAK) theory. The LUMet data presented here together with theoretical background showed that this technique can be successfully used as an additional tool to characterize microstructural evolution during industrially relevant non-isothermal treatments of Ti-alloys.
Research on the accuracy of Brain Fingerprinting (BFP) has produced mixed outcomes: some report 99.9% and others report lower. Furthermore, no studies have measured the susceptibility of BFP to ...countermeasures. In Experiment‐1, we report the accurate classification of 15 of the 16 subjects, tested on their own real‐life autobiographical incidents; and 14 of the 15 other subjects, tested on another subject's real‐life autobiographical incidents. In Experiment‐2, 16 subjects of Experiment‐1, who were tested on their own real‐life incidents, participated in the BFP test again, but this time employing either direct‐suppression or thought‐substitution (n = 8 each) countermeasures. We report that neither direct‐suppression nor thought‐substitution was effective at concealing information that BFP was designed to reveal. We assert that BFP is a highly accurate, albeit not perfect, concealed‐knowledge detection technology and that it is resistant to memory suppression and thought substitution countermeasures in the context of autobiographical incidents.
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