Avaliação da durabilidade de misturas asfálticas a quente e mornas contendo material asfáltico fresado.

A reciclagem de misturas asfálticas usando técnicas de misturas mornas atende às exigências da sustentabilidade, limitando o consumo de energia e de novos materiais. A reciclagem de revestimentos asfálticos fresados (RAP) é praticada há mais de 40 anos, por meio de usinagem a quente do RAP adicionado a agregados e ligante novos. Todavia, o uso de elevadas taxas de RAP (acima de 25% no total), é um grande desafio até o presente, pois limita a perda de durabilidade da mistura asfáltica final. O RAP contém ligante asfáltico envelhecido aderido aos agregados, porém uma parte desse ligante pode ser remobilizada durante a reciclagem pelo aumento da temperatura no processo de usinagem. Esta tese busca compreender o processo de remobilização do ligante envelhecido durante a reciclagem do RAP e as consequências da magnitude de temperatura empregada no processo de reaquecimento deste material envelhecido. Atualmente, tem-se buscado o uso da tecnologia de usinagem morna, permitindo a redução de temperatura total no processo de fabricação. Um dos problemas possíveis da combinação das técnicas reciclagem morna é a ocorrência do fenômeno de recobrimento duplo, que pode impactar na reologia do novo material: o ligante do RAP e o ligante novo não se misturariam totalmente, devido à redução das temperaturas de fabricação, formando camadas superpostas. Este fenômeno seria a causa de disfuncionamentos mecânicos da mistura asfáltica final. Questiona-se então a qualidade do recobrimento dos agregados do RAP, já recobertos, e a falta de um meio de caracterização para a observação da interface. Neste estudo, a qualidade do recobrimento do RAP foi avaliada em escala microscópica e macroscópica. No nível microscópico, foi proposto o uso de uma ferramenta de micro-espectroscopia infravermelha para avaliar a interface entre o RAP e o ligante novo, e seguir a distribuição espacial desses dois componentes na mistura asfáltica. Para tanto, foi realizado um desenvolvimento experimental detalhado que permitisse o uso de um acessório de imagem infravermelha em misturas asfálticas recicladas. Graças à indentificação prévia de marcadores internos, foi possível acompanhar a mobilização parcial do ligante envelhecido do RAP. Em paralelo, no nível macroscópico, foi desenvolvido um protocolo de ensaio com o objetivo de avaliar a durabilidade das misturas asfálticas recicladas com taxas elevadas de RAP (50%), com o objetivo princial de compreender se há benefícios nas propriedades mecânicas de misturas mornas recicladas. O ensaio de fadiga é um dos ensaios que permitem melhor avaliar e comparar diferentes misturas asfálticas para comporem uma camada de pavimento. Porém, este ensaio não pode ser diretamente transposto à previsibilidade de campo por ter restrições, tais como o ligante das amostras ensaiadas não teve tempo de envelhecer; e as misturas asfálticas, dependendo da quantidade de RAP e da temperatura de usinagem, podem envelhecer em velocidades diferentes em campo. No presente trabalho, foi proposta a adição de uma etapa de envelhecimento previamente aos ensaios mecânicos. Foi suposto que o comportamento real do material estaria situado entre o do material não envelhecido e do envelhecido. Os principais resultados mostram que uma mistura reciclada morna apresenta resultados satisfatórios de comportamento mecânico que atestam seu uso como camada de revestimento asfáltico, exceto que ela tem a tendência de ser mais sensível à fadiga que uma mistura com a mesma composição de agregados e de teor de ligante, fabricada a quente ou morna, mas sem a adição de RAP.

Geological risk assessment of Amtoudi Agadir in southern Morocco: a key case for sustainable cultural heritage

Medieval fortified granaries known as “agadirs” are very common in southern Morocco, being catalogued as world cultural heritage by United Nations. These Berber buildings (made of stones and tree trunks) usually located on rocky promontories, constitute historical testimonials related to the origin of Morocco, and, as tourist attractions, have a positive impact on the local economy. The sustainability of these ancient monuments requires geological-risk evaluations of the massif stability under the agadir with the proposal of stabilization measures, and an architectonic analysis with appropriate maintenance of the structural elements. An interdisciplinary study including climate, seismicity, hydrology, geology, geomorphology, geotechnical surveys of the massif, and diagnosis of the degradation of structural elements have been performed on the Amtoudi Agadir, selected as a case study. The main findings from this study are that the prevalent rocks used for construction (coming from the underlying substratum) are good-quality arkosic sandstones; the SW cliffs under the agadir are unstable under water saturation; some masonry walls are too thin and lack interlocking stones and mortar; and failures in the beams (due to flexure, fracture, and exhaustion in the resistance due to insect attacks or plant roots) are common. The basic risk assessment of ancient buildings of cultural heritage and their geologic substratum are needed especially in undeveloped areas with limited capacity to implement durable conservation policies. Therefore, recommendations have been provided to ensure the stability and maintenance of this important archaeological site.

Physical and chemical evaluation of furniture waste briquettes

Furniture waste is mainly composed of wood and upholstery foam (mostly polyurethane foam). Both of these have a high calorific value, therefore, energy recovery would be an appropriate process to manage these wastes. Nevertheless, the drawback is that the energy content of these wastes is limited due to their low density mainly that of upholstery foam. Densification of separate foam presents difficulties due to its elastic character. The significance of this work lies in obtaining densified material by co-densification of furniture wood waste and polyurethane foam waste. Densification of furniture wood and the co-densification of furniture wood waste with polyurethane foam have been studied. On the one hand, the parameters that have an effect on the quality of the furniture waste briquettes have been analysed, i.e., moisture content, compaction pressure, presence of lignin, etc. The maximum weight percentage of polyurethane foam that can be added with furniture wood waste to obtain durable briquettes and the optimal moisture were determined. On the other hand, some parameters were analysed in order to evaluate the possible effect on the combustion. The chemical composition of waste wood was compared with untreated wood biomass; the higher nitrogen content and the concentration of some metals were the most important differences, with a significant difference of Ti content.

Did the German court do Europe a favor? Bruegel Working Paper 2014/09, July 2014

The European Central Bank’s Outright Monetary Transactions (OMT) programme was a politically-pragmatic tool to diffuse the euro-area crisis. But it did not deal with the fundamental incompleteness of the European monetary union. As such, it blurred the boundary between monetary and fiscal policy. The fuzziness of this boundary helped in the short-term but pushed political and economic risks to the future. Unless a credible commitment to enforcing losses on private creditors is instituted, these conundrums will persist. The German Federal Constitutional Court has helped by insisting that such a dialogue be conducted in order to achieve a more durable political and economic solution. A study of the European Union Court of Justice’s Pringle decision (Thomas Pringle v Government of Ireland, Ireland and The Attorney General, Case C-370/12, ECJ, 27 November 2012) suggests that the ECJ will also not rubber-stamp the OMT – and, if it does, the legal victory will not resolve the fundamental dilemmas.

The fragile ‘reset’. The balance sheet and the prospects for changes in Russian-US relations. OSW Point of View (Policy Brief), April 2011

The ‘reset’ policy proposed by the USA has brought Russia a number of geopolitical, prestigious and economic benefits. The most important of those are: the resumption of arms control, the USA’s withdrawal from plans to locate elements of its strategic missile defence system in Poland and the Czech Republic, and the entry into force of the so-called 123 Agreement. In response, Russia has assisted the United States in resolving the Iranian crisis, and offered help with the Afghanistan operation, covering the transit of supplies and supporting the Afghan government. Moscow has also eased up on its anti-American rhetoric. The changes which have taken place in Russian-US relations are not durable. The two parties have not resolved their major disputes (for example, regarding missile defence), and any differences are hushed up for tactical reasons.

The oligarchic democracy: The influence of business groups on Ukrainian politics. OSW Study 42/2012

The Ukrainian oligarchic system, which developed into its ultimate shape during Leonid Kuchma’s second presidency, turned out to be very durable. The nature of close relations between the government and the oligarchs has not undergone any major changes either as a consequence of the Orange Revolution or following Victor Yanukovych’s victory in the presidential election of 2010. Although reshuffles have taken place inside the political and business elites, nothing seems to be able to change this system, at least in the medium term. This text is aimed at presenting the network of connections existing between big business and politics in Ukraine and at pointing to the key oligarchic groups and the political forces they support. A definite majority of papers concerning contemporary Ukrainian politics as a rule disregard or deal with this subject very superficially, while it is impossible to understand modern Ukraine without understanding a number of dependencies existing between the political and business elites there.

Is the EU-Central Asia Strategy running out of steam? EUCAM Policy Brief No. 17, May 2011

The EU’s Central Asia Strategy approaches its fourth anniversary. In that time the EU has placed its relationship with Central Asia on a more structured footing. Although progress has been made in building dialogue and in furthering engagement, the strategy’s limitations are increasingly obvious. This brief argues that the driving force of the EU engagement should be based on a closer link between security and development. Engagement in this broad field should be underpinned by a values based approach that seeks to promote more explicitly reform on human rights, rule of law, governance and democracy. The momentous changes sweeping across the Middle East and North Africa have demonstrated that even the most apparently durable authoritarian regimes are vulnerable to sudden political shocks.

Ramzanistan. Russia's Chechen Problem. OSW POINT OF VIEW Number 54, 2015-08-25

The political activity and growing independence of Chechnya’s leader Ramzan Kadyrov raises questions about his loyalty and the possibility of his openly renouncing his servitude to Moscow. Such a scenario seems unlikely because of the dependence of Kadyrov’s regime on Russia. He is burdened by his republic’s financial dependence, the stain of collaboration and the crimes committed on his own people, and so his regime cannot exist without Moscow’s support. However, Kadyrov’s dependence on Moscow and the apparent stability of the situation in Chechnya do not mean that a lasting peace has been established there. The current plan for governing the republic and the relationship between Moscow and Grozny is a temporary solution, based not on durable solutions, but on the situational convergence of the Kremlin and Kadyrov’s interests. A change of government in the Kremlin, or to an even greater degree a domestic crisis in Russia which weakens its position in the Caucasus, would mean the fall of Kadyrov’s regime, and the reactivation of pro-independence rhetoric in Chechnya.

Interplay between cardiac function and heart development

Mechanotransduction refers to the conversion of mechanical forces into biochemical or electrical signals that initiate structural and functional remodeling in cells and tissues. The heart is a kinetic organ whose form changes considerably during development and disease. This requires cardiomyocytes to be mechanically durable and able to mount coordinated responses to a variety of environmental signals on different time scales, including cardiac pressure loading and electrical and hemodynamic forces. During physiological growth, myocytes, endocardial and epicardial cells have to adaptively remodel to these mechanical forces. Here we review some of the recent advances in the understanding of how mechanical forces influence cardiac development, with a focus on fluid flow forces. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Develomental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.

The true and false pacifism,

Who is responsible for the present war and what is at stake?--The birth of pan-Germanism.--The progress and aims of German militarism.--The movement towards international reform.--Some illusions entertained by Germany.--Pacifism and an indecisive peace.--A durable peace.--A definitive peace.

Encyclopédie méthodique : Agriculture /

Datos de los t. V-VII tomados de ejemplares del ICCU y del COPAC.

Move the goods!

Mode of access: Internet.

Images & mirages /

Author's name at head of title.

Lyrics of lowly life,

Mode of access: Internet.