170 research outputs found
Water activity and freezing points in aqueous solutions of manganese nitrate: experimental and modeling
The water activities of manganese nitrate solutions were measured using a
humidity sensor instrument up to almost the saturation molality at 298.15 K; the thermodynamic
properties of the system were described by the Pitzer model and specific
interaction theory (SIT). The evaluation of the ion interaction parameters for the Pitzer
model and SIT were carried out using experimental freezing points and osmotic coefficients
of manganese nitrate aqueous solutions, collected from the open literature, and the
water activity data measured in this work. A set of Pitzer and SIT parameters were
estimated using a temperature dependency, that enables us to cover wider temperature
ranges, and consequently calculate system properties to higher molalities. Both approaches
represent very satisfactorily, and with similar accuracy, the experimental data and the
calculated manganese nitrate molal activity coefficients are comparable to those already
published for analogous systems. Additionally, the Pitzer model was also able to calculate
the ice curve and the solubility branch of manganese nitrate hexahydrate up to a salt
solution 6.5 mol-kg-1.This work was developed in the scope of the projects POCI-01-0145-FEDER-
006984—Associate Laboratory LSRE-LCM both funded by European Regional Development Fund (ERDF)
through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI)—and by
national funds through FCT—Fundação para a Ciência e a Tecnologia. This work is also a result of project
‘‘AIProcMat@N2020—Advanced Industrial Processes and Materials for a Sustainable Northern Region of
Portugal 2020’’, with the reference NORTE-01-0145-FEDER-000006, supported by Norte Portugal
Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through
ERDF.info:eu-repo/semantics/publishedVersio
Low-Temperature Plasma-Enhanced Atomic Layer Deposition of SiO2 Using Carbon Dioxide
In this work, we report the successful growth of high-quality SiO2 films by low-temperature plasma-enhanced atomic layer deposition using an oxidant which is compatible with moisture/oxygen sensitive materials. The SiO2 films were grown at 90 degrees C using CO2 and Bis(tertiary-butylamino)silane as process precursors. Growth, chemical composition, density, optical properties, and residual stress of SiO2 films were investigated. SiO2 films having a saturated growth-per-cycle of similar to 1.15 angstrom/cycle showed a density of similar to 2.1g/cm(3), a refractive index of similar to 1.46 at a wavelength of 632nm, and a low tensile residual stress of similar to 30MPa. Furthermore, the films showed low impurity levels with bulk concentrations of similar to 2.4 and similar to 0.17at. % for hydrogen and nitrogen, respectively, whereas the carbon content was found to be below the measurement limit of time-of-flight elastic recoil detection analysis. These results demonstrate that CO2 is a promising oxidizing precursor for moisture/oxygen sensitive materials related plasma-enhanced atomic layer deposition processes.Peer reviewe
From peripheral region to escalator region in Europe: young Baltic graduates in London
This paper examines recent migration from three little-studied European Union (EU) countries, the Baltic states, focusing on early-career graduates who move to London. It looks at how these young migrants explain the reasons for their move, their work and living experiences in London, and their plans for the future, based on 78 interviews with individual migrants. A key objective of this paper is to rejuvenate the core–periphery structural framework through the theoretical lens of London as an ‘escalator’ region for career development. We add a necessary nuance on how the time dimension is crucial in understanding how an escalator region functions – both in terms of macro-events such as EU enlargement or economic crisis, and for life-course events such as career advancement or family formation. Our findings indicate that these educated young adults from the EU’s north-eastern periphery migrate for a combination of economic, career, lifestyle and personal-development reasons. They are ambivalent about their futures and when, and whether, they will return-migrate
Optimising the antibiotic treatment of uncomplicated acute appendicitis: a protocol for a multicentre randomised clinical trial (APPAC II trial)
DiscussionTo our knowledge, APPAC II trial is the first randomised controlled trial comparing per oral antibiotic monotherapy with intravenous antibiotic therapy continued by per oral antibiotics in the treatment of uncomplicated acute appendicitis. The APPAC II trial aims to add clinical evidence on the debated role of antibiotics as the first-line treatment for a CT-confirmed uncomplicated acute appendicitis as well as to optimise the non-operative treatment for uncomplicated acute appendicitis.</p
Secretory phospholipase A2 pathway in various types of lung injury in neonates and infants: a multicentre translational study
Background
Secretory phospholipase A2 (sPLA2) is a group of enzymes involved in lung tissue inflammation and surfactant catabolism. sPLA2 plays a role in adults affected by acute lung injury and seems a promising therapeutic target. Preliminary data allow foreseeing the importance of such enzyme in some critical respiratory diseases in neonates and infants, as well. Our study aim is to clarify the role of sPLA2 and its modulators in the pathogenesis and clinical severity of hyaline membrane disease, infection related respiratory failure, meconium aspiration syndrome and acute respiratory distress syndrome. sPLA2 genes will also be sequenced and possible genetic involvement will be analysed.
Methods/Design
Multicentre, international, translational study, including several paediatric and neonatal intensive care units and one coordinating laboratory. Babies affected by the above mentioned conditions will be enrolled: broncho-alveolar lavage fluid, serum and whole blood will be obtained at definite time-points during the disease course. Several clinical, respiratory and outcome data will be recorded. Laboratory researchers who perform the bench part of the study will be blinded to the clinical data.
Discussion
This study, thanks to its multicenter design, will clarify the role(s) of sPLA2 and its pathway in these diseases: sPLA2 might be the crossroad between inflammation and surfactant dysfunction. This may represent a crucial target for new anti-inflammatory therapies but also a novel approach to protect surfactant or spare it, improving alveolar stability, lung mechanics and gas exchange
Narrative enquiry
It is falling increasingly to international organisations and institutions to provide a coherent and workable global value system which embraces difference internally and externally with compliance expected from every level of the organisation. International human rights conventions and statutory regulations require compliance to human rights principles putting such organisations at the forefront of cultural relations. A global values framework gives them the opportunity to shake off colonial pasts and to strive to make a good business case for adherence to such principles. As principles are more challenging to enact than to formulate, to support this values portfolio, research is needed into how principles can be enacted in every day matters of the organisation. Current literature highlights the use of storytelling as sense-making and, as such, has become a growing trend in the use of the narrative approach across disciplines and professional sectors. Its contributors are from anthropology, education, linguistics, translation studies, literature, politics, psychology and sociology, organization studies and history. This chapter surfaces the link between local and grand narratives through an ethno narrative approach contextualised within a recent study of EDI and specifically Global Diversity Management
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