Contact angle of a hemispherical bubble: an analytical approach

We have calculated the equilibrium shape of the axially symmetric Plateau border along which a spherical bubble contacts a flat wall, by analytically integrating Laplace’s equation in the presence of gravity, in the limit of small Plateau border sizes. This method has the advantage that it provides closed-form expressions for the positions and orientations of the Plateau border surfaces. Results are in very good overall agreement with those obtained from a numerical solution procedure, and are consistent with experimental data. In particular we find that the effect of gravity on Plateau border shape is relatively small for typical bubble sizes, leading to a widening of the Plateau border for sessile bubbles and to a narrowing for pendant bubbles. The contact angle of the bubble is found to depend even more weakly on gravity

Energy, competition and innovation: how policies’ coordination may contribute to a new energy model

The aim of this paper is to shed light on the role played by the coordination of public policies – competition and innovation policies - in achieving a new organizational model in the energy sector. The acknowledgement that the use of energy represents a main issue in today’s world, due to its impact on the sustainability of global resources, is the central driver for the current debate. Taking investment in the renewables energy sector as a proxy to innovation, the paper shows that policies coordination is likely to promote a swifter transition to a new energy system. The paper is focused on the electricity industry and market in Portugal, but its main assertions are likely to apply to other European countries and to other network industries.FC

Spikes in Cosmic Crystallography

If the universe is multiply connected and small the sky shows multiple images of cosmic objects, correlated by the covering group of the 3-manifold used to model it. These correlations were originally thought to manifest as spikes in pair separation histograms (PSH) built from suitable catalogues. Using probability theory we derive an expression for the expected pair separation histogram (EPSH) in a rather general topological-geometrical-observational setting. As a major consequence we show that the spikes of topological origin in PSH's are due to translations, whereas other isometries manifest as tiny deformations of the PSH corresponding to the simply connected case. This result holds for all Robertson-Walker spacetimes and gives rise to two basic corollaries: (i) that PSH's of Euclidean manifolds that have the same translations in their covering groups exhibit identical spike spectra of topological origin, making clear that even if the universe is flat the topological spikes alone are not sufficient for determining its topology; and (ii) that PSH's of hyperbolic 3-manifolds exhibit no spikes of topological origin. These corollaries ensure that cosmic crystallography, as originally formulated, is not a conclusive method for unveiling the shape of the universe. We also present a method that reduces the statistical fluctuations in PSH's built from simulated catalogues.Comment: 25 pages, LaTeX2e. References updated. To appear in Int. J. Mod. Phys. D (2002) in the present for

Betalains and phenolic compounds of leaves and stems of Alternanthera brasiliana and Alternanthera tenella

Betacyanins and phenolic compounds from acetonitrile:acidified water extracts of Alternanthera brasiliana and Alternanthera tenella were characterized and quantified using a high-performance liquid chromatography system coupled with diode array and electrospray mass spectrometry detection. Four betacyanins (amaranthine, isoamaranthine, betanin and isobetanin) were tentatively identified and quantified. Twenty eight phenolic compounds of four different families (hydroxybenzoic and hydroxycinnamic acids, flavones and flavonols) were separated and characterized on the basis of their accurate MS and MS/MS information out of which ten compounds were confirmed by authentic standards. These plant species could be considered as an especially rich source of natural bioactive compounds and potential food colorants. A. brasiliana showed the highest betacyanin and polyphenols content (89 μg/g and 35,243 μg/g, respectively). Among polyphenols, flavonols were the more abundant (kaempferol-glucoside, kaempferol-rutinoside and kaempferol-rhamnosyl-rhamnosyl-glycoside). Meanwhile, A. tenella showed a different polyphenols profile with flavones as major compounds (glucopyranosil-vitexin and vitexin). As a novelty, pentosyl-vitexin and pentosyl-isovitexin were detected for the first time in Alternanthera plants. Both A. brasiliana and A. tenella leaves showed high total polyphenol content and in vitro antioxidant activity (FRAP). These results provide an analytical base concerning the phenolic and betalains composition and the antioxidant properties of two members of the promising Alternanthera gender, for subsequent applications, such as functional food ingredients.Fil: Deladino, Lorena. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Alvarez, I.. Consejo Superior de Investigaciones Científicas. Instituto de Ciencia y Tecnologia de Alimentos y Nutrición; EspañaFil: De Ancos, B.. Consejo Superior de Investigaciones Científicas. Instituto de Ciencia y Tecnologia de Alimentos y Nutrición; EspañaFil: Sánchez Moreno, C.. Consejo Superior de Investigaciones Científicas. Instituto de Ciencia y Tecnologia de Alimentos y Nutrición; EspañaFil: Molina García, A. D.. Consejo Superior de Investigaciones Científicas. Instituto de Ciencia y Tecnologia de Alimentos y Nutrición; EspañaFil: Schneider Teixeira, Aline. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Consejo Superior de Investigaciones Científicas. Instituto de Ciencia y Tecnologia de Alimentos y Nutrición; Españ

The use of flocculating brewer's yeast for Cr(III) and Pb(II) removal from residual wastewaters

The use of inexpensive biosorbents to sequester heavy metals from aqueous solutions, is one of the most promising technologies being developed to remove these toxic contaminants from wastewaters. Considering this challenge, the viability of Cr(III) and Pb(II) removal from aqueous solutions using a flocculating brewer's yeast residual biomass from a Portuguese brewing industry was studied. The influence of physicochemical factors such as medium pH, biomass concentration and the presence of a co-ion was characterised. Metal uptake kinetics and equilibrium were also analysed, considering different incubation temperatures. For both metals, uptake increased with medium pH, being maximal at 5.0. Optimal biomass concentration for the biosorption process was determined to be 4.5 g dry weight/l. In chromium and lead mixture solutions, competition for yeast binding sites was observed between the two metals, this competition being pH dependent. Yeast biomass showed higher selectivity and uptake capacity to lead. Chromium uptake kinetic was characterised as having a rapid initial step, followed by a slower one. Langmuir model describes well chromium uptake equilibrium. Lead uptake kinetics suggested the presence of mechanisms other than biosorption, possibly including its precipitation.Instituto de Biotecnologia e Química Fina (IBQF) - Junta Nacional de Investigação Cientifica e Tecnologica (J.N.I.C.T), project PEAM/SEL/516/95

Impact of pelvic radiotherapy on female sexuality

PURPOSE: To assess physical and psychological morbidity, sexual functioning and social and relationship satisfaction among women treated with pelvic radiotherapy. METHODS: Observational (case-control) study of 199 women: 98 submitted to pelvic radiotherapy for the treatment of uterine, rectal or anal cancers and 101 without a personal history of cancer and similar socio-demographic variables. These completed a socio-demographic and clinical questionnaire, and validated measures of psychological health (DASS: Lovibond and Lovibond in Behav Res Ther 33:353-343, 1995), sexual function (FSFI: Rosen et al. in J Sex Marital Ther 26:191-208, 2007), social support (ESSS: Ribeiro in Analise Psicologica 3:547-558, 1999) and relationship satisfaction (IMS: Hudson in The WALMYR assessment scales scoring manual 1992). RESULTS: Women submitted to pelvic irradiation reported a higher rate of adverse physical symptoms in the last month: fatigue 59 versus 25% (p < 0.001), lack of strength 42 versus 20% (p = 0.001), diarrhoea 24 versus 12% (p = 0.032), vaginal discharge 17 versus 7% (p = 0.024), skin erythema 9 versus 2% (p = 0.026). Levels of depression, anxiety and stress were higher among radiotherapy patients, but only reach statistical significance for the stress parameter (6.1 vs. 4.0, p = 0.012). Also these women reported lower scores of satisfaction with social support (57.2 vs. 62.2, p = 0.005) and sexual function (8.5 vs. 13.5, p = 0.049). No statistically significant differences occurred between the two groups regarding scores of relationship satisfaction (20.8 vs. 19.9, p = n.s.). CONCLUSIONS: Our results suggested that pelvic radiotherapy had a negative impact on female sexuality. Thus, interventions that would help to reduce this impact need to be designed and integrated into routine clinical practice

Alergia de Contacto a Metais num Período de 20 Anos no Centro de Portugal: Implicações das Directivas Europeias

INTRODUCTION: Metals are a common cause of allergic contact dermatitis. After the introduction of the EU Nickel Directive (1994/27/CE; 2004/96/EC) and, more recently, the Cement Directive (2003/53/EC) there has been a significant decrease in sensitization to metals mainly in the Nordic countries. The applicability of these directives and their impact in the Portuguese population is unknown. MATERIAL AND METHODS: A retrospective study (1992-2011) was carried out in our patch test clinic to assess the temporal trend of metal sensitization (nickel [Ni], cobalt [Co] and chromium [Cr]) along the last 20 years, particularly considering age, sex and its relation with occupational activity. RESULTS: Out of 5 250 consecutively patch-tested patients, 1 626 (31%) were reactive to at least one metal (26.5% to Ni; 10.0% to Co and 7.9% to Cr). Women had a higher prevalence of sensitization to Ni (34.4% vs 8.9%) whereas men were more reactive to Cr (11.5% vs 5.0%). Nickel sensitization did not decrease significantly over the years, although in recent years among women sensitized to nickel the percentage of younger patients (16-30 years-old) is significantly lower (p < 0.001). Chromium sensitization significantly decreased, particularly in men (r = -0.535), and mainly in the construction workers (r = -0.639). Chromium reactivity associated with the shoe dermatitis has remained stable. DISCUSSION: We emphasize the higher and stable percentage of nickel sensitized individuals suggesting, so far, a low impact from the EU Ni directive, although a decreasing percentage in the the younger group among Ni sensitized women may suggest a beneficial effect is becoming evident is this age group. On the contrary, the impact of the directive regarding the modification of Cr in cement seems to be effective. There is now a need to regulate chromium content in leather products, namely in shoes. CONCLUSIONS: The regulation of interventional measures related either to the manufacture and trade of adornments or professional use will better protect the population of allergy to metals.info:eu-repo/semantics/publishedVersio

Lignocellulose as raw material in fermentation processes

Lignocellulose in the form of forestry, agricultural, and agro-industrial wastes is accumulated in large quantities every year. These materials are mainly composed of three groups of polymers, namely cellulose, hemicellulose, and lignin. Cellulose and hemicellulose are sugar rich fractions of interest for use in fermentation processes, since microorganisms may use the sugars for growth and production of value added compounds such as ethanol, food additives, organic acids, enzymes, and others. Submerged and solid-state fermentation systems have been used to produce compounds of industrial interest from lignocellulose, as an alternative for valorization of these wastes and also to solve environmental problems caused by their disposal. When submerged fermentation systems are used, a previous stage of hydrolysis for separation of the lignocellulose constituents is required. This work is an overview about the potential uses of lignocellulosic materials in fermentation processes. Aspects related to submerged and solid-state fermentation systems will be described focusing on the raw materials, hydrolysis processes, fermentation conditions, microorganisms, and products that can be obtained