O IVA nas prestações de serviços de construção civil: inversão do sujeito passivo e taxas reduzidas

O setor da Construção Civil apresenta um fator importante na economia nacional. Porém, é considerado pela Autoridade Tributária e pela Comissão Europeia como um setor de risco na fraude e evasão fiscal. Assim, no seguimento de medidas implementadas pela Comissão Europeia, Portugal aprovou o Decreto-Lei 21/2007 de 29 janeiro, com o intuito de combater a fraude e evasão fiscal em sede Imposto sobre o Valor Acrescentado. Apesar disso, têm sido implementados incentivos aos serviços de construção civil, dos quais destacamos a taxa reduzida de Imposto sobre Valor Acrescentado, nomeadamente para a reabilitação urbana e para os serviços com alta intensidade de fator de trabalho. Pretendemos analisar pormenorizadamente esta legislação com a finalidade de esclarecer dúvidas omissas, adotando-se uma metodologia assente na análise de jurisprudência, Informações Vinculativas e doutrina. Da análise efetuada ficou evidente que o conceito de serviços de construção civil é muito amplo e de difícil definição introduzindo dificuldades na aplicação da taxa reduzida de IVA prevista nas verbas 2.23 e 2.27. No mesmo sentido verificou-se não serem aplicados pela AT os mesmo critérios na definição de serviços de construção civil para a regra de inversão do sujeito passivo e para a aplicação da taxa reduzida de IVA

Hybrid nanomaterials and nanoparticles for the prevention of biodeterioration of cultural heritage objects

Resumen del trabajo presentado al IX Congreso Ciencia y Arte, celebrado del 17 al 19 de octubre de 2022.N

Nanomateriales antimicrobianos para prevenir el biodeterioro del patrimonio cultural

Resumen del trabajo presentado a la 9ª Jornada de Jóvenes Investigadores de Química y Física de Aragón, celebrada en Zaragoza el 16 de diciembre de 2021.Peer reviewe

Polyoxometalate‐Ionic Liquids (POM‐ILs) as anticorrosion and antibacterial coatings for natural stones

Resumen del póster presentado al RSC Chemical Nanoscience and Nanotechnology Early Careers Virtual Meeting, celebrado el 24 de marzo de 2021.Peer reviewe

Iron Based Core-Shell Structures as Versatile Materials: Magnetic Support and Solid Catalyst

Core-shell materials are promising functional materials for fundamental research and industrial application, as their properties can be adapted for specific applications. In particular, particles featuring iron or iron oxide as core material are relevant since they combine magnetic and catalytic properties. The addition of an SiO2 shell around the core particles introduces additional design aspects, such as a pore structure and surface functionalization. Herein, we describe the synthesis and application of iron-based core-shell nanoparticles for two different fields of research that is heterogeneous catalysis and water purification. The iron-based core shell materials were characterized by transmission electron microscopy, as well as N2-physisorption, X-ray diffraction, and vibrating-sample magnetometer measurements in order to correlate their properties with the performance in the target applications. Investigations of these materials in CO2 hydrogenation and water purification show their versatility and applicability in different fields of research and application, after suitable individual functionalization of the core-shell precursor. For design and application of magnetically separable particles, the SiO2 shell is surface-functionalized with an ionic liquid in order to bind water pollutants selectively. The core requires no functionalization, as it provides suitable magnetic properties in the as-made state. For catalytic application in synthesis gas reactions, the SiO2-stabilized core nanoparticles are reductively functionalized to provide the catalytically active metallic iron sites. Therefore, Fe@SiO2 core-shell nanostructures are shown to provide platform materials for various fields of application, after a specific functionalization

Molecular and hybrid materials to prevent biodeterioration of cultural heritage objects

Trabajo presentado a la 13th Annual Conference CIBER-BBN (Centro de Investigación Biomédica en Red , Bioingeniería, Biomateriales y Nanomedicina), celebrada en Tarragona (España) del 21 al 22 de octubre de 2019

Molecular and nanomaterial for heritage conservation

Resumen del trabajo presentado al XVI Simposio de Investigadores Jóvenes de la Real Sociedad Española de Química -Sigma Aldrich (Merck), celebrado en Valencia del 4 al 7 de noviembre de 2019.Microorganisms are highly proficient at colonizing and decaying cultural heritage objects, generating serious problems for the conservation of paintings, textiles, sculptures and buildings. The associated health risks coupled with the cost associated with decontaminating infected artifacts, exhibition rooms and depots make this a pertinent topic for museums, local authorities and private collectors; while the design of new preventative and curative treatments represents a scientific challenge. The aim of our research in this field is to produce new materials with multifunctional properties (e.g. antimicrobial and anticorrosive) to prevent biodeterioration in objects of cultural heritage. As an example, the abstract image illustrates how modular, tunable polyoxometalate ionic liquid (POM-IL) materials offer a unique opportunity to produce precision biocides with anticorrosive properties that meet the specific needs of architectural heritage conservation. Our research demonstrates how comprehensive antimicrobial functional screening can be used to assess the activity of nanomaterials against bacterial and fungal strains commonly found colonizing objects of cultural heritage

Evaluating the durability and performance of polyoxometalate-ionic liquid coatings on calcareous stones: Preventing biocolonisation in outdoor environments

Rock-based materials exposed to outdoor environments are naturally colonised by an array of microorganisms, which can cause dissolution and fracturing of the natural stone. Biocolonisation of monuments and architectures of important cultural heritage therefore represents an expensive and recurring problem for local authorities and private owners alike. In this area, preventive strategies to mitigate biocolonisation are generally preferred to curative approaches, such as mechanical cleaning by brush or high-pressure cleaning, to remove pre-existing patina. The aim of this work was to study the interaction between biocidal polyoxometalate-ionic liquid (POM-IL) coatings and calcareous stones and evaluate the capacity of these coatings to prevent biocolonisation through a series of accelerated ageing studies in climate chambers, carried out in parallel with a two-year period of outdoor exposure in north-eastern France. Our experiments show that POM-IL coatings did not affect water vapour transfer nor significantly alter the total porosity of the calcareous stones. Simulated weathering studies replicating harsh (hot and wet) climatic weather conditions demonstrated that the colour variation of POM-IL-coated stones did not vary significantly with respect to the natural uncoated stones. Accelerated biocolonisation studies performed on the weathered POM-IL-coated stones proved that the coatings were still capable of preventing colonisation by an algal biofilm. However, a combination of colour measurements, chlorophyll fluorescence data, and scanning electron microscopy imaging of stones aged outdoors in northern France for two years showed that coated and uncoated stone samples showed signs of colonisation by fungal mycelium and phototrophs. Altogether, our results demonstrate that POM-ILs are suitable as preventative biocidal coatings for calcareous stones, but the correct concentrations must be chosen to achieve a balance between porosity of the stone, the resulting colour variation and the desired duration of the biocidal effect over longer periods of time, particularly in outdoor environments.This work was funded through the grant PID2019-109333RB-I00 funded by MCIN/AEI/10.13039/501100011033 (Ministerio de Ciencia e Innovación/Agencia Estatal de Investigación, Spain) and was supported by MCIN with funding from European Union NextGenerationEU (PRTR-C17.I1) promoted by the Government of Aragón. The authors also acknowledge the Fondo Social del Gobierno de Aragón (grupo DGA E15_20R) and the Programa Operativo Aragón de Fondo Social Europeo 2014-2020 (I.F.C.). The authors acknowledge the Servicio General de Apoyo a la Investigación-SAI (Universidad de Zaragoza), for the use of instrumentation as well as the technical advice provided by the National Facility ELECMI ICTS, node “Laboratorio de Microscopías Avanzadas” at University of Zaragoza. The authors wish to acknowledge professional support of the Interdisciplinary Thematic Platform from CSIC Open Heritage: Research and Society (PTI-PAIS).Peer reviewe

Modular molecular and hybrid nanomaterials to prevent biodeterioration of heritage objects

Resumen del trabajo presentado al World Meeting on Heritage, Sciences and Technologies, celebrado en Paris (Francia) del 14 al 15 de febrero de 2019.Microorganisms are highly proficient at inhabiting and decaying paper, leather and stone objects, generating serious problems for the conservation of paintings, textiles and sculptures. The associated health risks coupled with the cost of decontaminating infected artifacts, exhibition rooms and depots make this a pertinent topic for museums, local authorities and private collectors alike. Moreover, our shared cultural heritage is a social, economic and environmental resource for Europe. The overall aim of our current research efforts is to engineer a range of molecular and hybrid materials with enhanced antimicrobial properties, which act to help prevent the biodeterioration of cultural heritage objects. For example, modular and tunable polyoxometalate ionic liquid materials (POM-ILs) can act as precision biocides that meet the specific needs of cultural heritage conservation (e.g highly applicable colourless gels, waxes, sols etc.). Our research also demonstrates how comprehensive antimicrobial activity programs can be used to assess the activity of nanomaterials against bacterial and fungal strains commonly found infecting real heritage objects

Nanopartículas para preservación del Patrimonio Cultural

Resumen del trabajo presentado a la 8ª Jornada de Jóvenes Investigadores (Química y Física) de Aragón, celebrada en Zaragoza el dia 22 de noviembre de 2018.Peer Reviewe