New approach addressing sustainability in urban areas using sustainable city models

A brief analysis of the environmental, social and economic paradigm of nowadays cities, allows reaching a simple conclusion: current cities are not sustainable. Considering this, it is very important to study the causes of cities problems and to develop city models implementing sustainability practices. There are a limited number of studies developing sustainable city models, but the scientific community lacks even more studies about the rehabilitation of current cities to implement these models. This work emerges with the objective of analysing how it is possible to implement sustainability practices in cities through the development of a sustainable city model and an urban rehabilitation plan. The development of sustainable city models is a very complex topic and the analysis of the literature shows that it is necessary to consider the relation between environmental and social aspects in the development of sustainable cities, while taking special concerns when considering the economic issues. It was also concluded that sustainable city models and rehabilitation plans should be subject to sustainability assessments and should consider the active participation of its inhabitants. In fact, a city can only be sustainable if its population is in harmony with the city model and we can only assess results by predicting and measuring performance levels.(undefined

Use of acoustic energy in the processing of molten aluminium alloys

During the last years aluminium alloys have been gaining increased acceptance as structural materials in the automotive and aeronautical industries, mainly due to their light weight, good formability and corrosion resistance. However, improvement of mechanical properties is a constant in research activities, either by the development of new alloys or by microstructure manipulation. This presentation focuses a novel effective dynamic methodology to perform microstructural refinement / modification and degassing of light alloys, namely aluminium alloys, by applying acoustic energy to the melts. High intensity acoustic energy significantly improves the microstructure, therefore the mechanical properties of those alloys, avoiding the use of traditional chemically based degassing and refining techniques which are less effective and present significant environmental impact. Ultrasonic (US) vibration has proven to be extremely effective in degassing, controlling columnar dendritic structure, reducing the size of equiaxed grains and, under some conditions, producing globular grains and modifying the eutectic silicon cells in Al-Si alloys. The mechanisms of US processing of aluminium melts are discussed and experimental results on this field are presented.Fundação para a Ciência e Tecnologia (FCT

LA MUERTE DE LA NARRATIVA Y LA NARRATIVA DE LA MUERTE:

As múltiplas formas de comunicação podem nos levar a um cenário de desinformação, sedução, solidão e de morte com aquilo que presumimos enxergar. Estar vivo, hoje, aponta para a condição de estar virtualizado, digitalizado. Aqui, busca-se provocar uma reflexão com base em dois ensaios do escritor Walter Benjamin (1892-1940) envolvendo-os com o universo experienciado pela população LGBTI+, de maneira a compreender como as narrativas desta população são construídas e apresentadas nos ambientes midiáticos.The multiple forms of communication can lead us to a scenario of disinformation, seduction, loneliness and death with what we presume to see. Being alive, today, points to the condition of being virtualized, digitized. Here, we try to provoke a reflection based on two essays by the writer Walter Benjamin (1892-1940) involving them with the universe experienced by the LGBTI + population, in order to understand how the narratives of this population are constructed and presented in the mediatic environments.Las múltiples formas de comunicación pueden llevarnos a un escenario de desinformación, seducción, soledad y de muerte con lo que presumimos ver. El estar vivo, hoy, apunta a la condición de estar virtualizado, digitalizado. Aquí, se busca provocar una reflexión basada en dos ensayos del escritor Walter Benjamin (1892-1940) envolviéndolos con el universo experimentado por la población LGBTI +, de manera a comprender cómo las narrativas de esta población son construidas y presentadas en los ambientes mediáticos

Análise Comparativa Da Tensão Limite De Escoamento De Argamassas Por Meio Da Técnica De Pashias E Reometria Rotacional

Studies about the rheological behavior of cementitious materials, especially mortars and concretes, have been developed to improve the quality and durability of these materials as well as prevent any future problems in the hardened state. The rotational rheometry is the classic test for the rheological characterization of cementitious materials, because it allows to infer about the level of yield stress and apparent viscosity of the material. The rotational rheometers are, however, costly equipments, which led to the development of alternative me-thods for low cost, as the Pashias technique. The Pashias technique is a modification of the slump-test proce-dure in order to characterize, rheologically, the materials by single determining of the yield stress. The work developed aimed to determine the yield stress of mortars from compositions of high performance concretes (HPC) dosed by the concepts of rheology and particles packing. For this, it was used the classic rheometric test and the Pashias technique (cylinder), in order to compare the results, and evaluate the capacity of alterna-tive technique in determining the yield stress of mortars. The comparison of the results obtained by different rheological test methods showed a good ability of the Pashias technique (alternative technique) to evaluate the of yield stress parameter of mortars (with errors ranging from 1% to 20%). In addition, was observed that the mortar obtained from HPC dosed by the concepts of particles packing appeared more fluid and workable, with less yield stress. © 2016, Universidade Federal do Rio de Janeiro. All rights reserved.21486687

Sm3+ Effects In The Tm3+ Doped Tellurite Glass For S-band Amplification

Thulium doped Samarium codoped tellurite-tungstate glasses were produced. Luminescence properties in the infrared region were investigated looking to observe improved properties for S-band amplification in the co doped samples. Thulium is well-known by the 3H4-3F4 radiative transition emitting around ∼1.47μm, which is a self-terminating transition in tellurite hosts due the longer lifetime of the lower level in relation to the upper level of this transition. Analysis of absorption and emission spectra showed that we could quench the 3F4 level significantly, what improved the intensity of the emission at 1.49μm. However, the state 3H4 were also quenched due the cross relaxation process due the absorption bands of Sm3+ around 1.5μm. © 2013 Copyright SPIE.8601The Society of Photo-Optical Instrumentation Engineers (SPIE),NKT Photonics A/S,Fianium Ltd.,PolarOnyx, Inc.Zhang, G.-Q., Zhang, G.-Q., Yang, Q.-F., Cheng, S.-Q., Zhou, T., Evolution of the Internet and its cores (2008) New Journal of Physics, 10 (12), p. 123027. , doi:10.1088/1367-2630/10/12/123027Thomas, G., Shraiman, B., Glodis, P., Stephens, M., Towards the clarity limit in optical fibre (2000) Nature, 404 (6775), pp. 262-264. , doi:10.1038/35005034Tanabe, S., (2001) Properties of Tm3+ Doped Tellurite Glasses for 1.4 Um Amplifier, pp. 85-92Zhou, B., Lin, H., Pun, E.Y.-B., Tm3+-doped tellurite glasses for fiber amplifiers in broadband optical communication at 1.20 μm wavelength region (2010) Optics Express, 18 (18), pp. 18805-18810Liu, X., Chen, B.J., Pun, E.Y.B., Lin, H., Ultra-broadband near-infrared emission in praseodymium ion doped germanium tellurite glasses for optical fiber amplifier operating at E-, S-, C-, and L-band (2012) Journal of Applied Physics, 111 (11), p. 116101. , doi:10.1063/1.4722997Peng, M., Qiu, J., Chen, D., Meng, X., Yang, I., Jiang, X., Zhu, C., Bismuth- and aluminum-codoped germanium oxide glasses for super-broadband optical amplification (2004) Optics Letters, 29 (17), pp. 1998-2000Peng, M., Dong, G., Wondraczek, L., Zhang, L., Zhang, N., Qiu, J., Discussion on the origin of NIR emission from Bi-doped materials (2011) Journal of Non-Crystalline Solids, 357 (11-13), pp. 2241-2245. , Elsevier B.V. doi:10.1016/j.jnoncrysol.2010.11.086Allen, R., Esterowitz, L., An Efficient 1.46 um Thulium Fiber Laser via a Cascade Process (1993) Journal of Quantum Eletronics Letters, 29 (2), pp. 303-306Shen, S., Jha, A., Zhang, E., Wilson, S., Tm3+-Ho3+ and Tm3+-Tb3+ energy transfer in tellurite glass (2007) Journal of Luminescence, 126 (2), pp. 434-440. , doi:10.1016/j.jlumin.2006.08.092Tanabe, S., Properties of Tm3+-doped tellurite glasses for 1.4um amplifier (2001) Proceedings of SPIE, 4282, pp. 85-92Chillcce, E.F., Barbosa, L.C., Cruz, C.H.B., Tellurite photonic crystal fiber made by a stack-and-draw technique (2006) Journal of Non-Crystalline Solids, 352, pp. 3423-3428. , doi:10.1016/j.jnoncrysol.2006.02.12

Scalar field in the Bianchi I: Non commutative classical and Quantum Cosmology

Using the ADM formalism in the minisuperspace, we obtain the commutative and noncommutative exact classical solutions and exact wave function to the Wheeler-DeWitt equation with an arbitrary factor ordering, for the anisotropic Bianchi type I cosmological model, coupled to a scalar field, cosmological term and barotropic perfect fluid. We introduce noncommutative scale factors, considering that all minisuperspace variables $\rm q^i$ do not commute, so the symplectic structure was modified. In the classical regime, it is shown that the anisotropic parameter $\rm \beta_{\pm nc}$ and the field $\phi$, for some value in the $\lambda_{eff}$ cosmological term and noncommutative $\theta$ parameter, present a dynamical isotropization up to a critical cosmic time $t_{c}$; after this time, the effects of isotropization in the noncommutative minisuperspace seems to disappear. In the quantum regimen, the probability density presents a new structure that corresponds to the value of the noncommutativity parameter.Comment: 17 pages, 6 figures, Acepted in IJT

Will ultrathin CIGS solar cells overtake the champion thin-film cells? Updated SCAPS baseline models reveal main differences between ultrathin and standard CIGS

Cu(In,Ga)Se2 (CIGS) solar cells are amongst the best performing thin-film technologies, with the latest performance gains being mainly due to recent years improvements obtained with post-deposition treatments (PDT). Moreover, thinning of the absorber layer down to sub-micrometre values (ultrathin absorbers) is of extreme importance for CIGS to be even more cost-effective and sustainable. However, electrical and optical limitations, such as rear interface recombination and insufficient light absorption, prevent the widespread implementation of ultrathin CIGS devices. The recent electrical CIGS simulation baseline models have failed to keep up with the experimental developments. Here an updated and experimentally based baseline model for electrical simulations in the Solar Cell Capacitor Simulator (SCAPS) software is presented and discussed with the incorporation of the PDT effects and increased optical accuracy with the support from Finite-Difference Time-Domain (FDTD) simulation results. Furthermore, a champion solar cell with an equivalent architecture validates the developed thin-film model. The baseline model is also applied to ultrathin CIGS solar cell devices, validated with the ultrathin champion cell. Ultimately, these ultrathin models pave the way for an ultrathin baseline model. Simulations results reveal that addressing these absorbers' inherent limitations makes it possible to achieve an ultrathin solar cell with at least 21.0% power conversion efficiency, with open-circuit voltage values even higher than the recent thin-film champion cells.This work was supported by the Fundação para a Ciência e Tecno-logia (FCT) grant numbers DFA/BD/7073/2020, DFA/BD/4564/2020, SFRH/BD/146776/2019, IF/00133/2015, UIDB/50025/2020, UIDP/50025/2020, UIDB/04730/2020, and UIDP/04730/2020. The authors want to acknowledge the funding from the project NovaCell (PTDC/ CTM-CTM/28075/2017). The authors also acknowledge the financial support of the project Baterias 2030, with the reference POCI-01-0247-FEDER-046109, co-funded by Operational Programme for Competitiveness and Internationalization (COMPETE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDFinfo:eu-repo/semantics/submittedVersio

(Non)commutative isotropization in Bianchi I with Barotropic perfect fluid and Λ\Lambda Cosmological

We present the classical solutions to the Einstein field equations derived using the WKB-like and Hamilton procedures. The investigation is carried out in the commutative and noncommutative scenario for the Bianchi type I cosmological model coupled to barotropic perfect fluid and $\lambda$ Cosmological for two different gauges. Noncommutativity is achieved by modifying the symplectic structure considering that all minisuperspace variables $\rm q^i$ does not commute and by a deformation between all the minisuperspace variables. In the gauge N=1, it is possible to obtain that the anisotropic parameter $\rm \beta_{\pm nc}$ tend to a constant curvature for large period of time considering different values in the noncommutative parameters $\theta$ and cosmological term. However, this behavior give the idea that is necessary introduce other class of matter in the models, for to have a real isotropization in the model, such as dark energy or dark matter.Comment: 15 pages, 1 figur

Estudos sobre a nutriçao mineral do arroz: XXVII . Fatores que influenciam a absorção radicular do fósforo pela variedade IAC-164

Within the range of 15 to 240 minutes it was found that absorption increased in a linear fashion.By varying the external concentration of H2PO-4 from 10-7M to 10-2 M a dual pattern uptake was observed: a high affinity macnamism with a Km= 6.17 x 10-6M and a second one with low affinity (Km= 1.64 x 10-2M) . Absorption was raised when the external concentration of Mg ions varied from 10-6 to 10-4When supplied in the range of 10-6 to 10-2M the chloride salis of K and Ca rediced the absorption, the effect being traced to the CI ion. Zincsulfate (10-8to 10-4M) had no effect on phosphate absorption.Na faixa de 15 a 240 minutos a absorção do fósforo marcado com P32 é crescente e linear. A variação na concentração externa de H2PO4 mostrou existirem duas isotermas, uma operando em baixas concentrações (Km = 6,17x10-6M) e outra correspondente a altas concentrações (Km = 1,64x10-2M). Oíon magnésio aumenta a absorção e o Cl- causa diminuição quando fornecido na concentração de 10-2m.SO4-2e Zn+2 não mostraram efeito