Experimental analysis on the functional properties of rendering mortars with superficial addition of TiO2 nanoparticles

Recent developments in the area of nanomaterials science and nanotechnology are changing the field of construction and building industry. The construction industry has been increasingly identified as an important market for the use of nanomaterial´s since this can make buildings cleaner (minimizing the pollution effects and also reducing the building facades maintenance costs), resistant and energy efficient (thermal energy storage). In order to contribute for the development of this area, this work aims the production of rendering plastering mortars with multifunctional properties such as photocatalytic capacity and improving thermal capabilities. Standard plastering mortars were modified by spraying titanium dioxide (TiO2) from a water-based TiO2 nanoparticles solution. Two mortar compositions, which are representative of rendering mortars, namely composition, 1:1:6 and 1:2:9 (cement:lime:sand) in volume, were considered. Additionally, two distinct water/binder ratios were considered to induce distinct porosities and thus to evaluate the differences on the mechanical and physical properties of the mortars after the addition of the TiO2 nanoparticles

Reconsiderando o efeito Fisher: uma análise de cointegração entre taxas de juros e inflação [Rethinking the Fisher Effect: a co-integration analysis between interest rates and inflation]

This paper investigates the validity of the Fisher effect hypothesis that it is the interest rate which moves to adjust to the anticipated changes in the rate of inflation. The analysis is carried out with monthly data for the period 1980-97 for three countries with recent histories of chronic high inflation: Argentina, Brazil, and Mexico. A co-integration analysis has provided evidence of a stable long-run equilibrium relationship between nominal interest rates and the inflation rate for the cases of Argentina and Brazil only.inflation, interest rate, monetary policy

Classical electromagnetic field theory in the presence of magnetic sources

Using two new well defined 4-dimensional potential vectors, we formulate the classical Maxwell's field theory in a form which has manifest Lorentz covariance and SO(2) duality symmetry in the presence of magnetic sources. We set up a consistent Lagrangian for the theory. Then from the action principle we get both Maxwell's equation and the equation of motion of a dyon moving in the electro-magnetic field.Comment: 10 pages, no figure

Towards an ergonomic assessment framework for industrial assembly workstations - a case study

Work-related musculoskeletal disorders (WMSD) are one of the main occupational health problems. The best strategy to prevent them lies on ergonomic interventions. The variety of industrial processes and environments, however, makes it difficult to define an all-purpose framework to guide these ergonomic interventions. This undefinition is exacerbated by recurrent introduction of new technologies, e.g., collaborative robots. In this paper, we propose a framework to guide ergonomics and human factors practitioners through all stages of assessment and redesign of workstations. This framework was applied in a case study at an assembly workstation of a large furniture enterprise. Direct observation of work activity and questionnaires were applied to characterize the workstations, the process, and the workers’ profiles and perceptions. An ergonomic multi-method approach, based on well-known and validated methods (such as the Finnish Institute of Occupational Health and Rapid Upper Limb Assessment), was applied to identify the most critical risk factors. We concluded that this approach supports the process redesign and tasks’ allocation of the future workstation. From these conclusions, we distill a list of requirements for the creation of a collaborative robot cell, specifying which tasks are performed by whom, as well as the scheduling of the human-robot collaboration (HRC).This work has been supported by NORTE-06-3559-FSE-000018, integrated in the invitation NORTE-59-2018-41, aiming the Hiring of Highly Qualified Human Resources, co-financed by the Regional Operational Programme of the North 2020, thematic area of Competitiveness and Employment, through the European Social Fund (ESF). This work has been also supported by FCT – Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020

Influência do envelhecimento acelerado no vigor de sementes de Anadenanthera colubrina (Vellozo) Brenan – Mimosaceae.

Anadenanthera colubrina (Vellozo) Brenan is a Mimosaceae tree used for pasture afforestation and its wood produces good quality parquet blocks, slats, packing, charcoal and firewood. This work aimed to study the species seed influence under accelerated aging treatments in order to evaluate seed vigour through germination test. The aging camera method was adopted with temperatures of 40 ± 2oC and humidity around 95%, with stay time zero (T1); 24 (T2); 48(T3); 72 (T4) and 96 hours (T5). Statistic design used was completely random, with four replicate and 25 seeds per treatment.  Germination test was carried out under 30oC temperature and continuous light with paper filter moistened as substrate. First counting was conducted on the fifth day and the last on the ninth day after trial establishment. Fresh seed germination was 98% and water content was 8,1%. It was observed that control treatment (T1), after 14 months of storge showed 75% germination and the others treatments showed germination between 32 and 21%. Accelerated aging caused loss of viability on the observed seeds, low percentage of normal plants and high percentage of deteriorated seeds. Accelerated aging decreased the seed germination speed.A espécie Anadenanthera colubrina (Vellozo) Brenan é uma Mimosaceae, de porte arbóreo, utilizada na arborização de pastos bem como a madeira é empregada na confecção de tacos, ripas, embalagens, lenha e carvão de boa qualidade. O objetivo deste trabalho foi estudar a influência do teste de envelhecimento acelerado no vigor de sementes dessa espécie. O ensaio foi conduzido utilizando o método da câmara de envelhecimento, com temperatura de 40 2oC e umidade relativa de 95%, com tempo de permanência zero (T1); 24 (T2); 48 (T3); 72 (T4) e 96 horas (T5). O delineamento utilizado foi o inteiramente casualizado, com quatro repetições de 25 sementes, por tratamento. O teste de germinação foi realizado à temperatura de 30oC, com luz constante, tendo como substrato rolo de papel. A primeira contagem foi efetuada no quinto dia e a última no nono dia da instalação. A germinação das sementes frescas foi de 98% e o teor de água de 8,1%. Observou-se que a testemunha (T1), após 14 meses de armazenamento, apresentou germinação de 75% e os demais tratamentos (T2, T3, T4, T5) apresentaram percentuais variando entre 32 e 21%. O envelhecimento acelerado provocou a perda da viabilidade das sementes estudadas. Registrou-se baixa percentagem de plântulas normais e alta de sementes deterioradas. O envelhecimento acelerado provocou um declínio na velocidade de germinação das sementes da espécie

Real-time intracellular temperature imaging using lanthanide-bearing polymeric micelles

Measurement of thermogenesis in individual cells is a remarkable challenge due to the complexity of the biochemical environment (such as pH and ionic strength) and to the rapid and yet not well-understood heat transfer mechanisms throughout the cell. Here, we present a unique system for intracellular temperature mapping in a fluorescence microscope (uncertainty of 0.2 K) using rationally designed luminescent Ln3+-bearing polymeric micellar probes (Ln = Sm, Eu) incubated in breast cancer MDA-MB468 cells. Two-dimensional (2D) thermal images recorded increasing the temperature of the cells culture medium between 296 and 304 K shows inhomogeneous intracellular temperature progressions up to ∼20 degrees and subcellular gradients of ∼5 degrees between the nucleolus and the rest of the cell, illustrating the thermogenic activity of the different organelles and highlighting the potential of this tool to study intracellular processes.publishe

1-Methyl-7-(4-nitro­phen­yl)-3-phenyl­pyrazolo[3,4-b]pyrrolo[3,4-d]pyridine-6,8(3H,7H)-dione

In the title compound, C21H13N5O4, the dihedral angles formed between the planes of the phenyl and nitro­phenyl rings and that of the heterotricyclic plane are 41.29 (7) and 61.35 (6)°, respectively. In the crystal, weak C—H⋯O interactions help to establish the packing

Feeding habits of Enyalius perditus (Squamata: Leiosauridae) in an Atlantic Forest remnant in southeastern Brazil

Hábitos alimentares de Enyalius perditus (Squamata: Leiosauridae) em um fragmento de Mata Atlântica no sudeste do Brasil. O objetivo do presente estudo foi fornecer informações sobre hábitos alimentares e outros aspectos ecológicos do lagarto Enyalius perditus em um fragmento de Mata Atlântica no estado do Rio de Janeiro, sudeste do Brasil. No Rio de Janeiro, os indivíduos de E. perditus alimentaram-se predominantemente de artrópodes, como lagartas, isópodes e aranhas, como é típico de lagartos desse gênero. Não houve variação pronunciada nos principais tipos de presas consumidas entre essa e outras populações de E. perditus estudadas, apesar de haver diferenças potenciais nos suprimentos alimentares entre ambientes. Os indivíduos consumiram fragmentos de folhas mortas, ingeriram presas comumente encontradas na serapilheira (e.g., Isopoda e larvas de Coleoptera) e foram algumas vezes encontrados no chão ou capturados em armadilhas-de-queda durante os trabalhos de campo, o que sugere que esses lagartos utilizam a serapilheira do chão da floresta para o forrageio e outras atividades, embora também utilizem poleiros acima do nível do chão.Feeding habits of Enyalius perditus (Squamata: Leiosauridae) in an Atlantic Forest remnant in southeastern Brazil. In the present study, we aimed to provide information regarding feeding habits and other ecological aspects of Enyalius perditus in an Atlantic Forest remnant in the state of Rio de Janeiro, southeastern Brazil. Enyalius perditus individuals in Rio de Janeiro fed predominantly upon arthropods such as caterpillars, isopods, and spiders, as is typical of lizards in the genus. There were no pronounced variations in the main types of prey consumed between this and other populations of E. perditus studied in spite of potential differences in local food supplies between environments. The individuals consumed fragments of dead leaves, ingested prey commonly found in leaf litter (e.g., Isopoda and Coleoptera larvae), and were sometime

Herbage Accumulation and Mass in Massai Grass Plots Mixed with Forage Peanut and Fertilized with Nitrogen

The objective of this work was to evaluate herbage accumulation and mass during the growing season of Massai grass mixed with peanut forage and fertilized with nitrogen. The work was carried out at Federal Rural University of Rio de Janeiro, Brazil, from 11/2021 to 03/2022. A randomized block experimental design was used, in plots of Massai grass Megathyrsus maximus, in a factorial arrangement, with seven replications. Four treatments formed by the combination of the presence or absence of Archis pintoi and nitrogen fertilization (0 and 50 kg ha-1 of N). Canopy heights of the plots were evaluated weekly and when they reached values of about 50 cm two samples were collected and the total herbage accumulation and mass were calculated. The treatments without nitrogen fertilization and legume had the lowest herbage accumulation and mass (5,080 and 2,060 kg ha-1 of DM, respectively), when compared to the plots that had nitrogen fertilization and legume. The treatments with or without legume but with nitrogen fertilization had the same herbage accumulation and mass (9,775 and 2,630 kg ha-1 of DM, respectively). Thus, the presence of the legume resulted in greater herbage accumulation and mass in relation to those plots without legume and nitrogen fertilization. However, when nitrogen fertilization was performed no additive effect with the presence of the legume was observed, indicating that the nitrogen fertilization somehow inhibited the benefit of the legume on forage production. So, based on the short-term results obtained, the use of nitrogen fertilization or the use of forage peanuts should be done separately