Viabilidad de la implantación de sistemas de cerramiento total para reducir las emisiones difusas de partículas

Tras la entrada en vigor de la Directiva de Prevención y Control Integrados de la Contaminación (Directiva IPPC) las actividades afectadas por la misma, incluidas las del sector cerámico, se han visto obligadas a controlar la emisión de partículas difusas mediante la implantación de medidas correctoras, que en muchos casos suponen un impacto económico significativo. En los casos más exigentes, las Autorizaciones Ambientales Integradas (AAIs) otorgadas a empresas del sector cerámico requieren el cerramiento total de las operaciones de gestión de materias primas. En el presente trabajo se evalúa la viabilidad técnica, económica y ambiental de la implantación de un sistema de cerramiento o confinamiento total como medida de reducción de emisiones difusas al considerarse una de las Mejores Técnicas Disponibles (MTDs). El estudio se ha realizado sobre una instalación de fabricación de gránulo atomizado considerando las operaciones de recepción, gestión y almacenamiento de materias primas.Peer reviewe

Adaptive Function and Brain Evolution

Contains fulltext : 108558.pdf (publisher's version ) (Open Access

Targeting tumour vasculature by inhibiting activin receptor-like kinase (ALK)1 function

Angiogenesis is a hallmark of cancer and is now a validated therapeutic target in the clinical setting. Despite the initial success, anti-angiogenic compounds impinging on the vascular endothelial growth factor (VEGF) pathway display limited survival benefits in patients and resistance often develops due to activation of alternative pathways. Thus, finding and validating new targets is highly warranted. Activin receptor-like kinase (ALK)1 is a transforming growth factor beta (TGF-β) type I receptor predominantly expressed in actively proliferating endothelial cells (ECs). ALK1 has been shown to play a pivotal role in regulating angiogenesis by binding to bone morphogenetic protein (BMP)9 and 10. Two main pharmacological inhibitors, an ALK1-Fc fusion protein (Dalantercept/ACE-041) and a fully human antibody against the extracellular domain of ALK1 (PF-03446962) are currently under clinical development. Herein, we briefly recapitulate the role of ALK1 in blood vessel formation and the current status of the preclinical and clinical studies on inhibition of ALK1 signalling as an anti-angiogenic strategy. Future directions in terms of new combination regimens will also be presented

Viabilidad de la implantación de sistemas de cerramiento total para reducir las emisiones difusas de partículas

Following the entry into force of the IPPC directive, the activities that it affects, which include the ceramic sector, have needed to control fugitive particle emissions by implementing corrective measures that often entail significant economic costs. In the most demanding cases, the Integrated Environmental Authorisations (IEA) awarded to companies in the ceramic industry require total enclosure of the raw materials handling operations. This paper evaluates the technical, economic, and environmental feasibility of the implementation of a total enclosure or containment system as a way of reducing fugitive particle emissions, as this is considered one of the Best Available Techniques (BAT). The study was carried out on the raw materials reception, handling, and storage operations at a ceramic company that manufactures spray-dried powder granule

O Processo de coloração a seco de porcelanato. Parte 1: Variáveis envolvidas e influência sobre as propriedades das peças

Dentre as tipologias de revestimentos cerâmicos atualmente produzidos o porcelanato tem se destacado pela grande expansão em sua produção, observada nos últimos anos. O sucesso do produto se deve pelas propriedades técnicas e estéticas oferecidas. Dentro deste contexto a técnica de coloração a seco surge como alternativa a ser adotada no processamento da massa do material, pois confere ao produto características estéticas que podem ser obtidas através de uma simples mistura de pigmentos e grânulos atomizados. Entretanto, pouco se conhece sobre as variáveis envolvidas neste processo de mistura e a real interferência de cada uma delas nas propriedades apresentadas pelo produto queimado. Este trabalho apresenta o resultado de um estudo que revela o efeito das principais variáveis relacionadas à mistura do pigmento com os grânulos atomizados sobre as propriedades apresentadas pelo produto fina

Kinetic study of the thermal decomposition process of calcite particles in air and CO2 atmosphere

The thermal decomposition process of calcite particles (0.45–3.60 mm average diameter), made up of porous agglomerates of very small CaCO3 microcrystals, was studied in the 975–1216 K temperature range. The experiments were carried out under isothermal conditions in air atmosphere, in CO2 atmosphere, as well as in a gas stream comprising different concentrations of air and CO2. An equation is proposed that relates the calcite conversion degree to both reaction time and operating conditions. The equation satisfactorily fits to the experimental results obtained in the entire tested range of particle sizes and temperatures in all the studied carbon dioxide concentrations

Calcium carbonate decomposition in white-body tiles during firing in the presence of carbon dioxide

This study examines the thermal decomposition process of the calcium carbonate (calcite powder) contained in test pieces of porous ceramics, of the same composition as that used in manufacturing ceramic wall tile bodies, in the presence of carbon dioxide, in the temperature range 1123–1223 K. The experiments were carried out in a tubular reactor, under isothermal conditions, in a gas stream comprising different concentrations of air and carbon dioxide. Assuming that the relationship between the molar concentrations of CO2 on both sides of the gas–solid interface in the test pieces was conditioned by an equilibrium law of the form , the equation proposed in a previous paper was modified to correlate the results obtained when the experiments were conducted in the presence of carbon dioxide. The modified equation fitted well to the experimental data obtained in the temperature and carbon dioxide concentration ranges studied. The knowledge derived from this research has enabled the firing cycle used in the single-fire manufacture of this type of wall tile to be optimised

Effect of the Vitrification of Human Oocytes on the Binding Capacity and Acrosome Status of Human Sperm

Conocer los aspectos moleculares que acontecen en el proceso de unión de los espermatozoides humanos a la zona pelúcida (ZP) humana es uno de los grandes retos de la biología de la Reproducción. Por otra parte conocer si el proceso de fecundación puede verse afectado por la criopreservación de los gametos femeninos sigue siendo otra cuestión debatida en la literatura. En base a esto, el objetivo principal de este trabajo fue conocer si la vitrificación ovocitaria puede alterar la interacción de los espermatozoides con el glicocáliz de la ZP y demostrar si la ZP de estos ovocitos pierde la capacidad de inducir la reacción acrosómica en los espermatozoides. Según nuestros resultados el método de vitrificación ovocitaria cerrado (S3) no altera la capacidad de unión de los espermatozoides a la zona pelúcida, ni la capacidad de ésta para inducir la reacción acrosómica.To know the molecular aspects that occur in the process of human sperm binding to the human zona pellucida (ZP) is one of the great challenges of reproduction biology. Moreover knowing if the fertilization process may be affected by cryopreservation of female gametes is still another issue discussed in the literature. Based on this, the main objective of this study was to determine whether the oocyte vitrification may alter the interaction of sperm with the glycocalyx of ZP and show whether these oocytes lost the ability to induce the acrosome reaction in sperm. According to our results the oocyte closed vitrification method (S3) does not alter the ability of the sperm binding to the zona pellucida, and their ability to induce the acrosome reaction.Este trabajo fue subvencionado por el Vicerrectorado de Investigación de la Universidad de Alicante (VIGROB-137)

Extension of the recorded host range of Caribbean Christmas tree worms (<i>Spirobranchus</i> spp.) with two Scleractinians, a Zoantharian, and an Ascidian

Caribbean Christmas tree worms (Annelida: Polychaeta: Serpulidae: Spirobranchus) are considered host generalists in their associations with anthozoan (Scleractinia) and hydrozoan (Millepora) stony corals [...

Análise e medida de fatores que afetam as curvaturas retardadas em porcelanato

Os revestimentos cerâmicos de porcelanato, tanto os esmaltados como os não esmaltados, apresentam um fenômeno conhecido como “curvaturas retardadas”, que consiste na mudança de curvatura das peças depois da saída do forno. Este fenômeno é mais problemático a medida de aumentam as dimensões das peças. Neste trabalho se quantificou a variação da curvatura ao longo do tempo em peças industriais de porcelanato esmaltado, observando-se que a curvatura parece apresentar uma evolução em um sentido (habitualmente em direção ao sentido côncavo, ou em forma de barco) para, após transcorrido certo tempo, inverter esta tendência. A cinética deste processo foi parametrizada considerando que existem dois mecanismos, simultâneos e antagônicos, com cinéticas diferentes.As análises teóricas apontam que somente existem dois fatores que podem produzir curvaturas retardadas: as tensões residuais e a expansão dos suportes. Em ambos os casos é necessário condições adicionais para que as curvaturas efetivamente se manifestem: Deste modo, por exemplo, a presença de tensões residuais não é sinônimo de curvaturas retardadas, mais sim um mecanismo adicional que permita a liberação progressiva destas tensões; este mecanismo é chamado de fluência. Além disso é necessário que o perfil de tensões residuais não seja simétrico em relação ao plano central da peça. No que diz respeito a expansão dos suportes, também são necessárias condições especiais para que estas possam provocar curvaturas retardadas; em particular, é necessário que estas sejam diferentes nas duas faces da peça (face lisa e tardoz). Uma expansão uniforme provocaria uma leve mudança dimensional, mas não uma curvatura retardada, nem mesmo para peças esmaltadas. A medida dos fatores que influenciam sobre as curvaturas retardadas é complexa pois requer o emprego de técnicas diferentes das habitualmente empregadas para a caracterização de revestimentos cerâmicos. Foram criados, especialmente para este trabalho, procedimentos para a medida dos diferentes fatores que produzem as curvaturas retardadas e se estudou a influencia de algumas variáveis sobre estes fatoresGlazed and unglazed porcelain tiles exhibit a phenomenon known as delayed curvatures, which consists of the change in tile curvature after the tiles leave the kiln. This phenomenon becomes more problematic as tile size increases. In this study, the variation of curvature in time has been quantified in industrial glazed porcelain tiles. It was observed that the curvature usually displays an evolution in one direction (customarily in a concave direction or vessel shape) which, after a certain time has elapsed, reverses this trend. The kinetics of this process has been parameterised, assuming there are two simultaneous, opposing mechanisms, with different kinetics. Theoretical analyses indicate that only two factors can produce delayed curvatures: residual stresses and expansion of the tile body. In both cases, additional circumstances need to occur for delayed curvatures to appear; thus, for example, the presence of residual stresses is not synonymous with delayed curvatures, but an additional mechanism is needed that allows progressive release of these stresses, a mechanism known as creep. In addition, the condition that the stress profile is not symmetrical with respect to the centre plane of the tile also needs to be obeyed. In regard to the expansion of the bodies, special conditions must also occur for these to cause delayed curvatures. In particular, it is necessary for the expansion at the tile fair face and at the rib face to be different. Uniform expansion would cause a slight dimensional change, but not a delayed curvature, not even in the presence of glaze. The measurement of the factors that influence delayed curvatures is complex because different techniques from those typically used in characterising ceramic tiles are required. Procedures have been fine-tuned to measure the different factors that give rise to delayed curvatures, and the influence of certain variables on these factors has been studiedVersió editoria