Local conjugacy classes for analytic torus flows

If a real-analytic flow on the multidimensional torus close enough to linear has a unique rotation vector which satisfies an arithmetical condition Y, then it is analytically conjugate to linear. We show this by proving that the orbit under renormalization of a constant Y-vector field attracts all nearby orbits with the same rotation vector.     

Thermal behavior of ara?a oil (Psidium cattleianum Sabine)

The ara?á is a well-known fruit, which belongs to the Myrtaceae family, Psidium cattleianum Sabine species, frequently found in the southern region of Brazil. The extraction of ara?a oil was carried out from seeds, and the fatty acid profile of this oil indicates the predominant presence of linoleic acid (81.38%). Thermogravimetry, derivative thermogravimetry, and differential scanning calorimetry (DSC) were used to characterize this oil. In addition, this oil was evaluated by DSC from 25 to ?60?°C, where the crystallization behavior was verified. Details concerning thermal decomposition as well as data of kinetic parameters of these stages have been described here. The kinetic behavior of the thermal decomposition was evaluated from several heating rates with mass samples of 5 and 20?mg in open crucibles under nitrogen and synthetic air atmospheres.     

Moisture profile measurements of concrete samples in vertical water flow by gamma ray transmission method

Samples of concrete for popular habitation (0.1×0.03×0.1 m) and cellular concrete (0.1×0.05×0.1 m) were submitted to water vertical ascending infiltration. The moisture content spatial and temporal evolution of each sample it was monitored in three halfway positions in a same horizontal line, applying the gamma rays transmission method. The data were taken with a 137Cs (3.7×1010 Bq, 0662 MeV) source, Nal (Tl) of 2×2″ detector coupled to gamma ray spectrometry standard electronic with multichannel analyzer and a micrometric table. For the popular habitation concrete, there was a clear correlation between wetting profiles and concrete strength. The cellular concrete showed a wetting profile compatible to its greater porosity.     

Activity Coefficients of Sodium Chloride in Water–Ethanol Mixtures: A Comparative Study of Pitzer and Pitzer–Simonson Models

Activity coefficients of NaCl were determined in water–ethanol solvents, in the range 5–20% (w/w) ethanol, from emf data. The molalities varied from 0.1 mol-kg^-1 to near saturation and measurements were taken in the temperature range 25–50°C. The Pitzer model was used to describe the nonideal behavior of the electrolyte and the corresponding coefficients were determined for each solvent. The Pitzer–Simonson equations were also applied and a detailed study, involving the short- and long-range forces, was done in order to better understand the different results obtained with both models.     

From Bulk to Nanoparticles: An Overview of Antiviral Materials,Its Mechanisms,and Applications

Infectious diseases caused by viruses are a global health concern and have become prominent in light of the recent COVID-19 pandemic. Considering the limitations of drugs and prophylactic methods used in current medicine, antiviral materials are a useful strategy in preventing the spread of viruses and enhancing treatment efficiency. Thus, this review highlights the state-of-the-art antiviral materials, describes the scientific landscape of the primary antiviral materials used based on bibliometric analysis, presents their mechanisms of action, and discusses their clinical applications. The mechanisms of action underlying the broad-spectrum antiviral properties of metals, ceramics, polymers, and composites are also discussed. Polyanions, polycations, oxides, and metal-based materials, from bulk to nanoparticles, have good potential in antiviral applications that may help prepare the world for future viral breakouts.     

Layer-by-layer immobilization of carbon dots fluorescent nanomaterials on single optical fiber

We report within this paper the development of a fiber-optic based sensor for Hg(II) ions. Fluorescent carbon nanoparticles were synthesized by laser ablation and functionalized with PEG₂₀₀ and N-acetyl-l-cysteine so they can be anionic in nature. This characteristic facilitated their deposition by the layer-by-layer assembly method into thin alternating films along with a cationic polyelectrolyte, poly(ethyleneimine). Such films could be immobilized onto the tip of a glass optical fiber, allowing the construction of an optical fluorescence sensor. When immobilized on the fiber-optic tip, the resultant sensor was capable of selectively detecting sub-micromolar concentrations of Hg(II) with an increased sensitivity compared to carbon dot solutions. The fluorescence of the carbon dots was quenched by up to 44% by Hg(II) ions and interference from other metal ions was minimal.     

On allocation of redundant components for systems with dependent components

In this paper we consider the problem of optimal allocation of a redundant component for series, parallel and k-out-of-n systems of more than two components, when all the components are dependent. We show that for this problem is naturally to consider multivariate extensions of the joint bivariates stochastic orders. However, these extensions have not been defined or explicitly studied in the literature, except the joint likelihood ratio order, which was introduced by Shanthikumar and Yao (1991). Therefore we provide first multivariate extensions of the joint stochastic, hazard rate, reversed hazard rate order and next we provide sufficient conditions based on these multivariate extensions to select which component performs the redundancy.     

Use of Multi-parameter Flow Cytometry as Tool to Monitor the Impact of Formic Acid on Saccharomyces carlsbergensis Batch Ethanol Fermentations

The use of lignocellulosic materials as substrate for bioethanol production is considered a cost-effective approach to make the biofuel production process economically sustainable. However, lignocellulosic hydrolysis releases toxic compounds such as weak acids which inhibit microorganism growth and ethanol production. In order to understand the physiological response of Saccharomyces carlsbergensis when fermenting glucose in the presence of formic acid (HF), the yeast growth was monitored by multi-parameter flow cytometry. Cytoplasmic membrane potential decreased as the HF concentration increased and as the yeast culture reached the stationary phase. However, the proportion of cells with permeabilized membrane did not increase with the HF concentration increase. The accumulation of reactive oxygen species was also monitored. Control and fermentations at low HF concentrations (<1 g/L) resulted in a high proportion of highly oxidized cells at the stationary phase. The multi-parameter flow cytometry approach proved to be a useful tool to monitor the physiological stress response of S. carlsbergensis growth and ethanol production in the presence of HF, an inhibitor present in lignocellulosic hydrolysates. The information here obtained at near real time can be used to enhance second-generation bioethanol production process efficiency.