The finite-volume method in computational rheology

The finite volume method (FVM) is widely used in traditional computational fluid dynamics (CFD), and many commercial CFD codes are based on this technique which is typically less demanding in computational resources than finite element methods (FEM). However, for historical reasons, a large number of Computational Rheology codes are based on FEM. There is no clear reason why the FVM should not be as successful as finite element based techniques in Computational Rheology and its applications, such as polymer processing or, more recently, microfluidic systems using complex fluids. This chapter describes the major advances on this topic since its inception in the early 1990’s, and is organized as follows. In the next section, a review of the major contributions to computational rheology using finite volume techniques is carried out, followed by a detailed explanation of the methodology developed by the authors. This section includes recent developments and methodologies related to the description of the viscoelastic constitutive equations used to alleviate the high-Weissenberg number problem, such as the log-conformation formulation and the recent kernel-conformation technique. At the end, results of numerical calculations are presented for the well-known benchmark flow in a 4:1 planar contraction to ascertain the quality of the predictions by this method

Smart management of waste from construction sites: mobile application technology in the city Manaus, Amazonas, Brazil

Construction and demolition waste (CDW) can be defined as a mixture of surplus materials generated from construction, renovation and demolition activities, including site cleaning, road works and demolition (Shen et al., 2004). Inadequate management of CDW, affects the environment, the economy and society (Jin et al. 2019). Besides increasing construction costs and real estate prices, CDW can have major negative impacts on the environment (Borja et al., 2019), namely the contamination of soil and watercourses with heavy metals that can cause diseases in the population and wild animals. These negative impacts are of major importance in sensitive natural environments, justifying the relevance of this research in the city of Manaus, in the central Amazon, Brazil. A previous study involved the quantification of CDW produced at 4 construction sites in the city of Manaus, and the costs involved in its management and disposal (Oliveira et al., 2019). The results showed that high quantities of wood and paper waste are produced, with considerable disposal costs, in spite of the high potential to recycle and re-use these types of waste. Metal waste was found to be the only CDW that was being adequately recycled in the construction sites under study, showing the importance of the implementation of an organized system to collect and recycle CDW in the city of Manaus (Oliveira et al., 2019). A similar case study conducted in the city of Santiago, capital of Chile, led to a quantification of the CDW volume for further management improvement proposals (Bravo et al., 2019). According to this study, in Santiago the generated volume of CDW per building area is 0.186 m3/m2, with a management cost of 75.47 US$/m3 (Bravo et al., 2019). These values are of the same magnitude as the ones found in the research study conducted in Manaus (Oliveira et al., 2019). Ogunmakinde et al. (2019) describe CDW management in Nigeria, highlighting the existing corruption and unethical practices of large companies who prefer to dig and bury the CDW in clandestine landfills, refusing to comply with environmental laws to avoid loss of profits. This lack of social and environmental responsibility in construction companies is unfortunately also a reality in Brazil. However, surveillance and monitoring of CDW production and disposal may not be the solution to combat clandestine landfill, as demonstrated in the study of Tsiliyannis et al. (2019), conducted in Athens, Greece. Environmental education and good practice are the best weapons we have in environmental management, and adequate CDW management requires a change in the behavior and attitude of each citizen (Mak et al., 2019). The studies conducted in the present investigation sought to define the current model of CDW management in the construction sites of the city of Manaus, its advantages and disadvantages, in order to verify the possibility of implementing a Circular Economy system (Farooque et al., 2019). This system could result in cost savings in civil construction and in the reduction of negative environmental impacts caused by the illegal disposal in clandestine landfills, which harms the lives of the citizens of the city of Manaus and the surrounding environment, the Amazon rainforest itself. Circular Economy CDW management systems have already been implemented in European cities (Fratini et al., 2019; Kravchenko et al., 2019), so why not extend this practice to cities in Latin America, which are also affected by the environmental and financial impacts of inadequate waste management on urban construction sites. In order to implement a Circular Economy model, construction companies must be adequately involved in this system, for example through the promotion of sharing and renting equipment, customers access and involvement, or the redesign of a product in order to make it more durable and easier to reassemble if repair is needed (Kravchenko et al., 2019). Scientific initiatives to develop new materials using CDW raw materials are very important for the sustainability of CDW management, such as ultra-high performance concrete (UHPC) which uses a fraction of waste together with natural sand (Wang et al., 2019). Technological developments are of the utmost importance in the process of improving environmental management in a Circular Economy model: digital networks and robotics are increasingly inserted in the context of environmental management, accompanying the development of the new “Industry 4.0” in the manufacturing sector (Sarc et al., 2019). Although the Circular Economy model is not yet implemented in Brazil, good practice initiatives are encouraged, as the one described in this paper regarding CDW waste management in constructions sites in the city of Manaus through the use of start-up technologies like mobile applications. These have an exponentially growing market worldwide, demonstrated by the increasing use of mobile applications running on smartphones, tablets, laptops and other mobile devices (Kaur & Kaur, 2019). The main objective of this research is to enhance adequate environmental management in construction sites through the development of a mobile application for CDW management. This tool can be used by construction companies, waste disposal companies, and even urban citizens who need to dispose construction waste.info:eu-repo/semantics/publishedVersio

Rentabilidade das explorações leiteiras em Portugal - dados técnicos e económicos

Com este trabalho, pretendemos avaliar os principais factores que condicionam a rentabilidade da exploração leiteira. Destaca-se o custo da alimentação que representa 50 a 68% do custo total de litro de leite produzido. Ao utilizar aplicações informáticas que formulem regimes alimentares ao mínimo custo, o produtor de leite consegue tomar decisões muito rápidas sobre as matérias-primas que vai utilizar no misturador Unifeed no dia seguinte. Só desta forma poderá ajustar ao regime alimentar as constantes variações dos preços das matérias-primas. A produção de milho e de azevém para silagem na própria exploração vai reforçar a menor dependência dos preços dos alimentos comprados fora, preços que o produtor individual não controla. Os parâmetros produtivos e reprodutivos adequados vão contribuir para o sucesso económico da exploração leiteira. O parâmetro produtivo DEL deve situar-se em 150 dias já que o seu aumento vai ter implicações directas na diminuição da produção média diária de leite. Parâmetros reprodutivos como o IP-P, o número de IA/IAF e a idade das novilhas ao primeiro parto com valores médios por estábulo, respectivamente, de 365 dias, 1,7 IA/IAF e 24 meses deverão ser o objectivo da exploração. Valores mais elevados vão ter implicações no custo do litro de leite produzido. As mamites contribuem para diminuir a quantidade e a qualidade do leite produzido. As bonificações atribuídas ao preço do leite com baixa CCS associada à redução da produção diária de leite pelas vacas com mamite são dois factores com implicações directas na rentabilidade da exploração.FC

Redes de interação proteica revelam fatores de risco associados à perturbação do espetro do autismo

Objetivo: No presente estudo foi colocada a hipótese de que fatores de risco comuns para a PEA convergem em vias fisiológicas específicas, e cumulativamente levam ao aparecimento de sintomas (6). Para identificar estas vias fisiológicas foi desenvolvido um método de análise de redes de interação proteína-proteína (protein-protein interaction, PPI), o qual envolve a sobreposição dos resultados de associação genómica obtidos em GWAS com redes de interação proteica previamente definidas. Esta abordagem pretende assim capturar informação de relevância biológica mesmo nos resultados negativos dos estudos de associação genómicos, e definir uma rede de interações proteicas (PPI) específica para a PEA

Flat histogram simulation of lattice polymer systems

We demonstrate the use of a new algorithm called the Flat Histogram sampling algorithm for the simulation of lattice polymer systems. Thermodynamics properties, such as average energy or entropy and other physical quantities such as end-to-end distance or radius of gyration can be easily calculated using this method. Ground-state energy can also be determined. We also explore the accuracy and limitations of this method. Key words: Monte Carlo algorithms, flat histogram sampling, HP model, lattice polymer systemsComment: 7 RevTeX two-column page

Electrogenerated hydrophilic carbon nanomaterials with tailored electrocatalytic activity

This work investigates the influence of the type of buffer electrolyte used in the generation of Electrochemical Hydrophilic Carbon (EHC) on their physical-chemical properties and electrocatalytic activity. The EHC nanomaterials were prepared in three different biological buffers, phosphate, glycine and citrate buffers (EHC@phosphate, EHC@glycine, EHC@citrate) and their surface properties were fully characterized by AFM, XPS and Raman. The EHC nanomaterials drop cast onto a glassy carbon electrode were electrochemically characterized in [Fe(CN)6]3-/4- and [Ru(NH3)6]3+/2+ redox probes solutions, and their electrocatalytic activity was investigated towards hydrogen peroxide and oxygen reduction reactions (ORR) in a phosphate buffer solution. It was found that the nature of buffer electrolyte strongly influences the surface chemical state of the EHC materials, disorder degree in the hexagonal sp2 carbon network and oxygen functional groups, affecting both the EHC electrocatalytic activity towards the ORR and H2O2 reduction reaction. The most catalytic material for the ORR was EHC@citrate, whereas EHC@glycine showed the highest oxygen conversion (n ≅ 2.7 to 3). Moreover, it was shown that the content of oxygen singly bonded to carbon correlates strongly with the number of electrons transferred. A very singular behaviour in the electrochemical reduction of hydrogen peroxide was observed on EHC@glycine, qualitatively interpreted as an autocatalytic reaction. In contrast, a blocking-like effect was depicted on EHC@phosphate. These results must have an important impact in the development of materials with peroxidase-like activity and in the design of O2 sensors with non-sensitivity to H2O2.publishe

Pharmaceutical drugs as emerging pollutants in aqueous media of Northeast Portugal

Emerging pollutants are potentially toxic substances that although found in very small concentrations can produce hazard effects to the environment. Due to their very small concentrations they are not yet included in the water quality monitoring programs neither in national or international environmental control regulations. Pharmaceutical and Personal Care Products (PPCPs) represent an important group of emerging pollutants owing to increased worldwide consumption and to their inherent capacity to induce physiological harmful effects in very low doses, which raises several concerns related with the potential adverse effects on humans, animals and environmental systems. In this work, it will be presented the development and validation of a complete experimental methodology proposed for the monitoring of pharmaceutical drugs. The method is based on solid phase extraction (SPE) followed by analysis with high performance liquid chromatography with a diode array detector (HPLC-DAD). Experimental results obtained with two different columns will be presented. An analytical Nucleosil 100-5 C18 column, 150 mm x 4.6 mm, obtained from Macherey-Nagel for compounds with lower pKa values and a SiliaChrom XT C18 column, 4.6 mm x 250 mm, obtained from SiliCycle for compounds with higher pKa values. The method is validated by the analysis of real aqueous matrices samples obtained from different water media sources, such as, swimming pools, rivers and wastewater treatment plants. To extend the scope of the analytical method and thus obtain a broader study, several drugs were selected, belonging to five different pharmacological classes: non-steroidal anti-inflammatory (ibuprofen, acetylsalicylic acid, ketoprofen, naproxen and diclofenac), analgesic (paracetamol), antibiotic (sulfamethoxazole), an anticonvulsant (carbamazepine) and a central nervous system stimulator (caffeine). These compounds were selected due to their high level of use and medical prescription and, consequently, leading to a high probability of environmental contamination.info:eu-repo/semantics/publishedVersio

Brief report: High frequency of biochemical markers for mitochondrial dysfunction in autism: no association with the mitochondrial aspartate/glutamate carrier SLC25A12 gene

In the present study we confirm the previously reported high frequency of biochemical markers of mitochondrial dysfunction, namely hyperlactacidemia and increased lactate/pyruvate ratio, in a significant fraction of 210 autistic patients. We further examine the involvement of the mitochondrial aspartate/glutamate carrier gene (SLC25A12) in mitochondrial dysfunction associated with autism. We found no evidence of association of the SLC25A12 gene with lactate and lactate/pyruvate distributions or with autism in 241 nuclear families with one affected individual. We conclude that while mitochondrial dysfunction may be one of the most common medical conditions associated with autism, variation at the SLC25A12 gene does not explain the high frequency of mitochondrial dysfunction markers and is not associated with autism in this sample of autistic patients

Composição nutricional do filete de três espécies piscícolas de águas interiores com interesse gastronómico

Composição nutricional do filete de três espécies piscícolas de águas interiores com interesse gastronómico

Índices de concorrência na elaboração de modelos de produção florestal

O autor apresenta os índices de concorrência (competição) mais recentes. Trabalhando com povoamentos jovens (6-39 anos de idade) de pinheiro silvestre, localizados na Baviera, foi-lhe possível estabelecer uma estreita correlação entre o crescimento em altura e a pressão de concorrência sofrida! por cada árvore. O autor calcula, para os seus povoamentos, diferentes índices espaço de crescimento (2.2.2.), apresenta um índice baseado na concorrência entre copas (2.2.3.2.), propõe diferentes adaptações (2.3.3.) do índice de concorrência do modelo de Hegyi (1974) e ensaia o índice de concorrência (2.4) de Assmann (1975). Foram seleccionados, pela sua alta correlação com o crescimento em altura da árvore individual, os índices espaço de crescimento e as diferentes adaptações do índice de concorrência do modelo de Hegyi (1974)info:eu-repo/semantics/publishedVersio