Exhaust Energy Recovery with Variable Geometry Turbine to Reduce Fuel Consumption for Microcars

The objective proposed by EU to reduce by about 4%/year CO2 emission of internal combustion engines for the next years up to 2030, requires to increase the engine efficiency and accordingly improving the technology. In this framework, hybrid powertrains can have the possibility of a deep market penetration since they may recover energy during brake, allow the engine to operate in better efficiency conditions and with less transients, Moreover, they can recover a large amount of energy lost through the exhaust and use it to reduce fuel consumption. This paper concerns the modification of a conventional two in-line cylinders Diesel engine (440 cm3) adding a variable geometry turbine (VGT) coupled with a generator. The turbine is used to recover exhaust gas energy that otherwise would be lost. The generator, connected to the turbo shaft, converts mechanical energy into electrical energy and is used to charge the vehicle battery or the auxiliaries. The aim of this work is reducing fuel consumption by replacing the alternator with a kind of electric turbo-compounding system to drive vehicle auxiliaries. If the selected turbine recovers enough energy to power auxiliaries, the alternator, which usually has low efficiency, can be removed. Along these lines, fuel consumption savings can be achieved. At a later stage, a microcar has been tested on WLTC (Class 1) driving cycle. The results show fuel consumption reduction of 6 to 9%, depending on VGT size. Indeed, four different VGT sizes have been analyzed to choose the optimal configuration that reflects a compromise between energy recovery and fuel consumption reductions

Public publishing on the web between autonomy and control: from ‘feudalism’ to ‘federation’?

The article, after some methodological notes and some pieces of information on the history of public publishing in Italy, focuses on the dissemination of official publications on the sites of the public administration. The underlying trends are identified in the emergence of open data and open government, in strong decentralization and in the weakening of any form of bibliographic control. After some examples taken from the experience of the most important European countries, the article concludes hoping for the development of a federation project of public publishing, based on decentralization and the use of standards, according to the open access model of institutional archives.L’articolo, dopo aver fornito alcune note metodologiche e informazioni sulla storia dell’editoria pubblica in Italia, si concentra sulla diffusione delle pubblicazioni ufficiali nei siti della pubblica amministrazione. Le tendenze di fondo sono individuate nell’emergere dei dati aperti e dell’open government, nel forte decentramento e nell’indebolimento di ogni forma di controllo bibliografico. Segue la presentazione di alcuni esempi tratti dall’esperienza dei più importanti paesi europei. In conclusione, l’autore auspica lo sviluppo di un progetto di federazione dell’editoria pubblica in rete basato sul decentramento e sull’uso di standard secondo il modello open acess degli archivi istituzionali

The kinetics of gold(III) extraction by pyridine-2-azo-p-dimethylaniline in water and in micellar systems

The kinetics of reaction between AuCl4−and the azo-dye pyridine-2-azo-p-dimethylaniline (PADA) havebeen investigated in water and in the presence of DTAC micelles, using classical spectrophotometryand the stopped-flow technique. PADA reacts with different chloro/hydroxo gold(III) complexes, in turnformed as the pH and Cl−concentration were changed, according to a network of parallel paths. In aqueoussolution, at low pH values, a fast step is observed which is ascribed to the ligand induced expulsion ofa labile water molecule from the reacting species Au(H2O)Cl3which forms at low pH values. At highervalues of pH, the reaction is much slower because, in the key step, PADA has to replace the more inertCl−ions in the gold coordination shell. In the presence of DTAC a remarkable catalytic effect is observed,owing to the absorption and attraction of the reactants on the micelle surface. Moreover, DTAC favors theformation of aquochloro aurates, thus inducing a change in the gold(III) speciation compared to that inwater. The analysis of the data suggests that the aquo species Au(H2O)Cl3and Au(H2O)2Cl2+play a majorrole in the reaction mechanism

The mechanism of the reaction between Au(III) and PADA in Sodium dodecylsulphate

The PADA/SDS system provides an excellent tool to selectively extract metal ions using the ligand-modified micellar-enhanced ultrafitration (LM-MEUF) technique. Application of this method to the extraction of Au(III) has required a detailed knowledge of the conditions under which the interaction of the metal ion with the extractor are optimal. For this purpose the kinetics and the equilibria of the reaction between tetrachloro-aurate ion and PADA have been investigated in water/SDS medium, exploring wide ranges of pH values and NaCl concentrations. Addition of PADA to the water/SDS medium results in the full adsorption of the ligand on the micelle and, in the presence of Au(III), the resulting Au-PADA complex is fully retained on the SDS surface. The binding process is, in fact, a ligand displacement reaction where PADA interacts with different Au(III) chloro-aquo complexes, displacing Cl− or OH− or H2O molecules, depending on pH. The reaction is biphasic and its mechanism is discussed. Experiments at different SDS concentrations show that the reaction of complex formation is retarded on going from pure water to a water/SDS mixture with [SDS] just above the cmc, while for further increases of the SDS content the reaction rate tends to stay constant. The obtained results enabled to establish that the reaction occurs on the SDS surface while the aquo-species, Au(H2O)Cl3 and Au(OH)3(H2O), which are not involved in the binding process in pure water, play an important kinetic role in the H2O/SDS medium

Gold(III) extraction and recovery and gold(III)/copper(II) separation using micelles

Gold extraction from aqueous solutions has been performed by micellar enhanced ultrafiltration (MEUF), using SDS and DTAC micelles. DTAC entraps 92-100% of the metal, which is present in form of AuCl4-, owing to electrostatic interaction. Using SDS the extraction of gold is unsuccessful. However, addition of PADA, as a metal extractor agent, according to the ligand modified micellar enhanced ultrafiltration (LM-MEUF) procedure, makes the extraction yield to approach 100% also with SDS. The recovery of gold entrapped in the micellar pseudo-phase has also been investigated. Different stripping agents have been used, the most efficient of them being a mixture of NaCl and NH3 which allowed the metal to be expelled from the micelle with a yield of 85%. Finally, Au(III)/Cu(II) separation is achieved with DTAC or SDS between pH 3 and 5. Almost 100% of Au(III) is retained on DTAC micelles while all Cu(II) remains in the aqueous medium, while the opposite occurs in SDS

A NEW BEHAVIOR AT THE LEK BY MALE VIOLET‐CROWNED PLOVERCRESTS (STEPHANOXIS LODDIGESII)

ABSTRACT ∙ Males of the Violet‐crowned Plovercrest (Stephanoxis loddigesii) exhibit a lekking reproductive system where agonistic interactions are relatively common. Here we describe a new behavior performed when Violet‐ crowned Plovercrest males are alone on perches. This study was conducted in 2011 at two Violet‐crowned Plovercrest leks located in semi‐deciduous forests of Rio Grande do Sul, Brazil. We performed ad libitum observations on seven males. The new behavior is always performed by solitary males. During the displays the hovering male with raised crest, pointed the beak towards the display perch while flying sideways in semicircles or circles. This behavior is similar to aggressive displays performed in front of perched rival males. Such a display is also present in other species of hummingbirds and may help to prepare males for aggressive aerial exhibitions or, alternatively, may represent a displacement behavior.RESUMO ∙ Um novo comportamento em leques de Beija‐flor‐de‐topete (Stephanoxis loddigesii) Machos do Beija‐flor‐de‐topete (Stephanoxis loddigesii) se agregam em leques, onde interações agonísticas são relativamente comuns. Aqui, nós descrevemos um novo comportamento que é realizado quando machos do Beija‐flor‐de‐ topete estão sozinhos nos leques. O estudo foi conduzido em 2011 em dois leques do Beija‐flor‐de‐topete localizados em uma Floresta Semidecidual, no estado do Rio Grande do Sul, Brasil. Nós utilizamos o método de ad libitum para observar sete machos. O novo comportamento é realizado por machos solitários. Durante as exibições, os machos pairam no ar com os seus topetes eriçados, dirigindo seus bicos para o poleiro de corte enquanto voam lateralmente formando círculos e semicírculos. Este comportamento é similar às exibições agressivas realizadas na frente de poleiros de machos rivais. Essa exibição também está presente em outras espécies de beija‐flores, e podem colaborar para preparar os machos para exibições agressivas aéreas ou, alternativamente, podem representar um comportamento de deslocamento

Origin and sustainability of the population of asteroids captured in the exterior resonance 1:2 with Mars

At present, approximately 1500 asteroids are known to evolve inside or sticked to the exterior 1:2 resonance with Mars at a ≃ 2.418 AU, being (142) Polana the largest member of this group. The effect of the forced secular modes superposed to the resonance gives rise to a complex dynamical evolution. Chaotic diffusion, collisions, close encounters with massive asteroids and mainly orbital migration due to the Yarkovsky effect generate continuous captures to and losses from the resonance, with a fraction of asteroids remaining captured over long time scales and generating a concentration in the semimajor axis distribution that exceeds by 20% the population of background asteroids. The Yarkovsky effect induces different dynamics according to the asteroid size, producing an excess of small asteroids inside the resonance. The evolution in the resonance generates a signature on the orbits, mainly in eccentricity, that depends on the time the asteroid remains captured inside the resonance and on the magnitude of the Yarkovsky effect. The greater the asteroids, the larger the time they remain captured in the resonance, allowing greater diffusion in eccentricity and inclination. The resonance generates a discontinuity and mixing in the space of proper elements producing misidentification of dynamical family members, mainly for Vesta and Nysa-Polana families. The half-life of resonant asteroids large enough for not being affected by the Yarkovsky effect is about 1 Gyr. From the point of view of taxonomic classes, the resonant population does not differ from the background population and the excess of small asteroids is confirmed.Fil: Tabaré Gallardo, Carlos. Universidad de la República; UruguayFil: Venturini, Julia. Universidad de la República; UruguayFil: Roig, Fernando Virgilio. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Gil Hutton, Ricardo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "el Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico ; Argentin

Eggshells as agro‐industrial waste substitute for CaCO3 in glass foams: A study on obtaining lower thermal conductivity

In this work, discarded glass bottles (GB) and eggshells (ES) were used to produce foam glass designed for thermal insulation. The literature on the thermal conductivity of foam glasses produced with eggshells is sparse. This material was used as pore‐forming agent at 3% and 5% weight fractions to obtain a foam glass with low thermal conductivity. Homogenized powders were uniaxially pressed, and the compacts were fired at three temperatures (800, 850, and 900°C). Raw materials were characterized by chemical analysis and particle size distribution. The foam glasses were characterized by their porosity, phases, compressive strength, and thermal conductivity. The best insulating properties were obtained for the composition containing 5 wt% ES fired at 800°C. This sample displayed a porosity of 91.4% while its thermal conductivity was of 0.037 W/m.K, with a compressive strength of 1.12 ± 0.38 MPa. Crystalline phases were observed in samples fired at 850 and 900°C as a result of the devitrification process. The final properties of the materials are comparable to those of commercial foam glasses obtained from non‐renewable, more expensive raw materials, a great indicator that the studied compositions could be used as an environmentally friendly substitute

A lindb e os princípios administrativos na gestão pública: mecanismo de contenção ao ativismo judicial desproporcional: Lindb and administrative principles in public management: mechanism for containing disproportional judicial activism

O presente artigo tem por objetivo expor as dificuldades enfrentadas pelos gestores públicos ao longo dos anos, pelo que poderá ser chamado de ativismo judicial desproporcional. O princípio da reserva financeira do possível é o mecanismo garantidor para que as políticas públicas universais não sejam preteridas em relação as individuais, como vem ocorrendo por meio das decisões jurisdicionais, onde este vem sendo injustamente mitigado e, muitas vezes, até mesmo desconsiderado. Para atenuar tal problemática, poderá o gestor público invocar as determinações trazidas pela Lei 13.655/2018, que estabelece novas diretrizes para interpretar e aplicar o direito público