Bounds on topological Abelian string-vortex and string-cigar from information-entropic measure

In this work we obtain bounds on the topological Abelian string-vortex and on the string-cigar, by using a new measure of configurational complexity, known as configurational entropy. In this way, the information-theoretical measure of six-dimensional braneworlds scenarios are capable to probe situations where the parameters responsible for the brane thickness are arbitrary. The so-called configurational entropy (CE) selects the best value of the parameter in the model. This is accomplished by minimizing the CE, namely, by selecting the most appropriate parameters in the model that correspond to the most organized system, based upon the Shannon information theory. This information-theoretical measure of complexity provides a complementary perspective to situations where strictly energy-based arguments are inconclusive. We show that the higher the energy the higher the CE, what shows an important correlation between the energy of the a localized field configuration and its associated entropic measure.Comment: 6 pages, 7 figures, final version to appear in Phys. Lett.

Hydrodynamics and gas-liquid mass transfer in an oscillatory flow reactor: influence of liquid properties

Available online 20 March 2023Liquid properties, such as, surface tension and viscosity are important parameters as they control gas-liquid mass transfer in bioprocesses. An oscillatory flow reactor provided with smooth periodic constrictions (OFR-SPC) was considered to evaluate its potential for mass transfer performance in non-pure gas-liquid systems. The effect of surface tension and viscosity on the volumetric (kLa) and liquid-side mass transfer coefficients (kL), interfacial area, (a), gas holdup (G) and bubbles dynamics were investigated under different operational conditions (oscillation amplitude (x0) and frequency (f) and superficial gas velocity (ug)). Two liquid phases, ethanol and sucrose aqueous solutions covering a range of surface tension and viscosity values were used. For the bubble size distribution (BSD) measurements an image analysis technique was used. A Design of Experiment (DoE) methodology was implemented in this work to establish the relation of x0, f, ug, surface tension and viscosity with kLa. According to the results, changes in the liquid properties and operational conditions showed marked effects on bubbles size and mass transfer. However, surface tension and viscosity had no significant influence on G, contrary to the reported for common contactors, where G increased in the presence of ethanol and decreased at moderate/high viscosities. Moreover, it was found that increasing the oscillatory movement notably improved kL, and kLa (2 to 6-fold), either in ethanol or sucrose solutions, compared to common reactors, even with moderate power consumption (~105 W m-3). This improvement resulted from the bubbles breakage, which originates bubbles with small and approximately the same size (homogeneous regime) enhancing a, instead, lower oscillations resulted in large bubbles (heterogeneous regime). The results demonstrate that the OFR-SPC can ensure outstanding mass transfer rates, with potential and feasibility for use in gas-liquid bioprocesses, where mass transfer and liquid properties are important.This work was financially supported by: I) Project PTDC/QEQ-PRS/3787/2014 -POCI-01–0145-FEDER-016816 - funded by the European Regional Development Fund (ERDF) through COMPETE2020 -Programa Operacional Competitividade e Internacionalização (POCI) and by national funds through Fundaç ão para a Ciência e a Tecnologia.I.P. (FCT) - Project 9471 - Reforçar a Investigaç ão,o Desenvolvimento Tecnológico e a Inovaç ão; II) IF exploratory Project [IF/01087/2014] funded by FCT; III) LA/P/0045/2020 (ALiCE), UIDB/00511/2020 and UIDP/00511/2020 (LEPABE), funded by national funds through FCT/MCTES (PIDDAC); IV) the FCT under the scope of the strategic funding of UIDB/04469/2020 unit, and by LABBELS – Associate Laboratory in Biotechnology, Bioengineering and Microelectromechnaical Systems, LA/P/0029/2020. A. Ferreira is an Investigador FCT. F. Almeida would wish to thank to FCT for PhD scholarship 2020.05246. BD.info:eu-repo/semantics/publishedVersio

Digital remote work influencing public administration employees satisfaction in public health complex contexts

The purpose of this study is to describe and analyze whether digital remote work in times of Covid-19 is influencing the satisfaction of Public Administration employees. Based on the objective of this study, an online survey was conducted in the Portuguese Public Administration, for a sample of 70 individuals, working at home due to the situation of Public Health caused by the Coronavirus. Digital remote work is being applied massively worldwide and is a specific form of work organization supported by information and knowledge. Digital remote workers carry out their activities at home and using digital technologies, depending on the nature of the tasks and work situations. To understand the satisfaction of Public Administration employees, an empirical study was carried out, supported by data collection through an online survey. The main conclusions were that despite the constraints (resistance of top management, organizational culture, autonomy, and flexibility of workers, among others) that existed before the health and socioeconomic crisis caused by the Coronavirus pandemic, digital remote work is a given in the life of organizations, public or private, and of workers with reflection at various levels in society and particularly in the professional fulfillment and satisfaction of employees. According to the analysis carried out on the data collected to support the conclusions of this study, the degree of satisfaction of Public Administration employees is influenced in different ways by the influencing factors studied: autonomy at work, conditions at work, and income. However, regarding the factor of quality of life at work, this link has not been established. Thus, it was possible to conclude that satisfaction increases positively and strongly with autonomy at work. Technological specialization and productivity still have a positive influence, but with low intensity contribute to the satisfaction of AP employees. Working conditions also negatively influence satisfaction, although at an average intensity. However, the average degree of job satisfaction varies according to the different age groups, with employees aged 35 or more having a higher satisfaction average than employees whose ages vary between 34 and the beginning of their working lives.info:eu-repo/semantics/publishedVersio

Aluminum recovery from water treatment sludges

Aluminum sulfate and polyaluminum chloride are widely used as coagulants in water treatment plants. A chemical sludge containing aluminium hydroxide, adsorbed organic matter and other water insoluble impurities is obtained after the flocculation-clarification process. In Portugal, an estimated amount of 66 000 ton/yr. (wet wt.) water treatment sludge is being disposed of on land or at municipal solid waste (MSW) landfills. Government restrictions to this practice as well as increasing deposition costs and the potential harmful impacts proceeding from the high aluminium content of the sludge have been leading to significant research efforts in order to evaluate different treatment alternatives, namely involving aluminium recovery and subsequent reuse. Despite membrane-based separation and liquid ion ex-change processes have been studied for that purpose, the traditional acidic and alkaline extraction methods may be still explored to obtain a product susceptible of use as coagulant for industrial waste-water treatment purposes. Centrifuged chemical sludge from a water treatment plant using polyaluminium chloride as coagulant was characterised in terms of humidity, volatile matter, Al, Fe, Mn, Cd, Cu, Cr, Pb, Ni and Zn. The dry sludge organic content is about 29% and the major elements determined are aluminium (~ 12.6%), iron (~ 2%) and manganese (~ 0.14%). The aluminium recovery was investigated both by acidic and alkaline leaching processes. Concentrated H2SO4 was selected as the acidic leaching medium and the process efficiency was evaluated at different operating conditions. The ratio dry sludge/sulphuric acid solution was varied between 0.5 and 2%, the pH ranged from 1.0 to 4.5, different stirring and settling times were established and the aluminium, iron and manganese dissolution was assessed. A similar study was performed at pH values between 10.0 and 13.6 using 2N/10N NaOH as the extracting solution and operating conditions as those of the acid extraction procedure. Whereas maximum alu-minium recovery using H2SO4 was about 61% at pH=1.0, the alkaline extraction led to aluminium recoveries of about 71% at pH = 13.6 (2% dry sludge in suspension, 90 min stirring time and 45 min settling time). Decreasing the sludge dosage to 0.5%, aluminium extraction increased to 87.4% at pH=13. As expected, acid extraction led to a higher Fe (18.2%) and Mn (42.1%) dissolution as com-pared with alkaline extraction at pH=13.6 (Fe=2.1% and Mn=3.2%)

Monopoles on string-like models and the Coulomb's law

The t'Hooft-Polyakov monopole mass can be substantially altered, in the thick GS and HC brane-world setup, and can be employed to constrain the brane thickness limit. In this work, we comprise a brief review regarding gauge fields localization in the string-like six dimensional brane-world models setup. The correction to the Coulomb's law in two models is studied. Besides, the monopole features are investigated from the point of view of the gauge fields localization in the string-like brane-worlds and its thickness.Comment: 14 pages, 7 figure

Heart Rate Variability during Plateau Waves of Intracranial Pressure: a pilot descriptive study

This study aims to describe heart rate variability during the first episode of plateau waves of intracranial pressure (ICP) in Traumatic Brain Injury (TBI) in order to characterize and identify at bedside this cerebrovascular phenomenon. The general behavior of the heart rate variability (HRV) spectral measures expressed in the medians across patients is concordant with an increased HRV in the latter part of the baseline and plateau wave, followed by a decrease after the event and a new increase during the recovery. In low and high frequency bands the same increase is more marked in the parametric analysis. Interpretation of HRV may help clinicians to better identify the plateau waves and allow earlier management