On Lattice Constructions D and D' from q-ary Linear Codes

Multilevel lattice codes, such as the associated to Constructions $C$, \overline{\mbox{D}}, D and D', have relevant applications in communications. In this paper, we investigate some properties of lattices obtained via Constructions D and D' from $q$-ary linear codes. Connections with Construction A, generator matrix, expressions and bounds for volume and minimum distances are derived. Extensions of previous results regarding construction and decoding of binary and $p$-ary linear codes ($p$ prime) are also presented

Fire-resistant bio-based polyurethane foams designed with two by-products derived from sugarcane fermentation process

There is a growing interest in replacing conventional fossil-based polymers and composites with waste-based materials and fillers for environmental sustainability. This study designed water-blown polyurethane rigid foams using two by-products from the Amyris fermentation process of producing β-farnesene. The distillation residue (FDR) served as the main polyol component in the foam’s formulation (PF), supplemented with 4.5% sugarcane bagasse ash (SCBA) as a fire-retardant filler (PFA). The study assessed the impact on foam properties. Based on the analysis of all compiled data (foam structure, mechanical, and thermal properties), it can be inferred that ash particles acted as nucleating points in the reaction media, leading to a reduction in foam density (from 134 to 105 kg/m3), cell size (from 496 to 480 nm), and thermal conductivity. The absence of chemical interaction between the ash filler and the polyurethane matrix indicates that the ash acts as a filler with a plasticizing effect, enhancing the polymer chain mobility. As a result, the glass transition temperature of the foam decreases (from 74 to 71.8 ºC), and the decomposition onset temperature is delayed. Although, the incorporation of 4.5% SCBA (grain size below 250 μm) was ineffective in the increment of the compressive strength, that small amount was enough to increase the foam’s specific strength from 1009 to 1149 m2/s2 suggesting that other factors (e.g. polyol feedstock, grain size, ash packing, etc.) are yet to be accounted. The flammability test results indicate that sugarcane bagasse ash improved the foam performance, reducing burning time from 251 to 90 s, time of extinguishment from 255 to 116 s, and burning length from 132 to 56.7 mm, meeting the fire protection standard UL 94, class HB. Despite the need for further improvement and detailed flammability evaluation, the results support the notion that polyurethane foams from renewable waste by-products offer a sustainable alternative to both edible and fossil-based sources. Additionally, sugarcane bagasse ash can be a suitable silica source for reinforcing composites with reduced flammability, potentially replacing harmful halogenated chemicals used for the same purpose.Work funded by AICEP (Agência para o Investimento e Comércio Externo de Portugal, E. P. E) through Alchemy—Capturing High Value from Industrial Fermentation Bio Products. Granting agency: Portugal 2020, European Regional Development Fund (FEDER). UIDB/04708/2020 and Programmatic Funding—UIDP/04708/2020 of the CONSTRUCT—Instituto de I&D em Estruturas e Construções—funded by national funds through the FCT/MCTES (PIDDAC)

Low-temperature performance of polymer-modified binders in stone mastic asphalts

When temperatures drop to significantly low levels, road pavements are subjected to thermally-induced stresses, resulting in the appearance of thermal cracking, among other distresses. In these situations, polymers can be used as asphalt binder modifiers to improve certain asphalt binder properties, such as elastic recovery, cohesion, and ductility. Polymers also minimize some of the problems of asphalt mixtures, such as thermal and fatigue cracking and permanent deformation. This work’s objective was to study the behavior of asphalt mixtures at low temperatures, mainly when using modified binders. Thus, three binders were selected and tested: a standard 50/70 penetration grade bitumen and two polymer-modified binders (PMB), obtained by adding, respectively, 2.5% and 5.0% of styrene–butadiene–styrene (SBS) in the 50/70 pen grade bitumen. Then, the PMBs were incorporated into stone mastic asphalt mixtures (namely SMA 11), which were subjected to low-temperature mechanical tests based on the most recent European Standards. The asphalt binders and mixtures evaluated in this work were tested for thermal cracking resistance, creep, elastic recovery, cohesive strength, and ductility strength. Overall, it is concluded that the studied asphalt mixtures with PMB, with just 2.5% SBS, performed adequately at low temperatures down to −20 °C.This research was funded by FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference code UIDB/04029/2020

Particle characteristics’ influence on FLASH sintering of potassium sodium niobate: A relationship with conduction mechanisms

Funding Information: This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the FCT/MEC and when appropriate, co-financed by FEDER under the PT2020 Partnership Agreement. This work was also financed by Portugal 2020 through European Regional Development Fund (ERDF), in the frame of Operational Competitiveness and Internationalization Programme (POCI), in the scope of the project "FLASH sintering of lead-free functional oxides towards sustainable processing of materials for energy and related applications-FLASH", POCI-01-0247-FEDER-029078. Ricardo Serrazina acknowledges FCT for financial support (SFRH/PD/BD/128411/2017).The considerable decrease in temperature and time makes FLASH sintering a more sustainable alternative for materials processing. FLASH also becomes relevant if volatile elements are part of the material to be processed, as in alkali‐based piezoelectrics like the promising lead‐free K0.5Na0.5NbO3 (KNN). Due to the volatile nature of K and Na, KNN is difficult to process by conventional sintering. Although some studies have been undertaken, much remains to be understood to properly engineer the FLASH sintering process of KNN. In this work, the effect of FLASH temperature, TF, is studied as a function of the particle size and impurity content of KNN powders. Differences are demonstrated: while the particle size and impurity degree markedly influence TF, they do not significantly affect the densification and grain growth processes. The conductivity of KNN FLASH‐sintered ceramics and KNN single crystals (SCs) is compared to elucidate the role of particles’ surface conduction. When particles’ surfaces are not present, as in the case of SCs, the FLASH process requires higher temperatures and conductivity values. These results have implications in understanding FLASH sintering towards a more sustainable processing of lead‐free piezoelectrics.publishersversionpublishe

Valorization of sugarcane by-products through synthesis of biogenic amorphous silica microspheres for sustainable cosmetics

Ashes from sugarcane by-product incineration were used to synthesize silica powders through alkaline hot extraction, followed by ethanol/acid precipitation or the sol–gel method. Both production methods allowed amorphous spherical silica microparticles with sizes ranging from 1–15 μm and 97% purity to be obtained. Water absorption ranged from 135–155 mL/100 g and 150–250 mL/100 g for precipitated silica and silica gel, respectively, while oil absorption ranged from 305 to 390 and from 250 to 350 mL/100 g. The precipitation with ethanol allowed the recovery of 178 g silica/kg ash, with a lab process cost of EUR 28.95/kg, while the sol-gel process showed a yield of 198 g silica/kg ash with a cost of EUR 10.89/kg. The experimental data suggest that ash from sugarcane by-products is a promising source to be converted into a competitive value-added product, minimizing the environmental impact of disposal problems.info:eu-repo/semantics/publishedVersio

Association between functional EGF+61polymorphism and glioma risk

Epidermal growthf actor (EGF) plays a critical role in cancer. A polymorphism in the EGF gene (EGF+61) may influence its expression and contribute to cancer predisposition and aggressiveness. In the present study, we aimed to elucidate the role of EGF+61in glioma susceptibility and prognosis. Experimental Design:A case-control study involving197 glioma patients and 570 controlswas done. Univariate and multivariate logistic regression analyses were used to calculate odds ratio (OR) and 95% confidence intervals (95% CI). False-positive report probability was also assessed.The luciferase reporter gene assay was used to ascertain the functional consequences of this polymorphism. Results: Corroborating the univariate analysis, the multivariate model showed that the G allele conferred higher risks for gliomas (OR,1.32; 95% CI,1.04-1.67), glioblastomas (OR,1.47; 95% CI, 1.02-2.10), and oligodendrogliomas (OR,1.55; 95% CI,1.07-2.23).TheGG genotypeswere associatedwithincreased risk for gliomas (OR,1.71; 95%CI,1.07-2.73), glioblastomas (OR, 2.03; 95% CI, 1.02-4.05), and oligodendrogliomas (OR, 2.72; 95% CI, 1.18-6.28). In addition, the AG+GG genotypes were associated withhigher risk for gliomas (OR,1.52; 95% CI,1.03-2.23) and oligodendrogliomas (OR, 2.80; 95% CI,1.35-5.79). No significant associationwas observed between the EGF+61polymorphism and glioblastoma or oligodendroglioma patients’overall survival. The luciferase reporter gene assay exhibited a significant increased promoter activity for the G variant compared withthe referenceA allele. Conclusions: These findings support the role of the EGF+61polymorphism as a susceptibility factor for development of gliomas and show its implication on EGF promoter activity.Sixth Research Framework Programme of the European Union, Project INCA (LSHC-CT-2005-018704

Deep-pretrained-FWI: combining supervised learning with physics-informed neural network

An accurate velocity model is essential to make a good seismic image. Conventional methods to perform Velocity Model Building (VMB) tasks rely on inverse methods, which, despite being widely used, are ill-posed problems that require intense and specialized human supervision. Convolutional Neural Networks (CNN) have been extensively investigated as an alternative to solve the VMB task. Two main approaches were investigated in the literature: supervised training and Physics-Informed Neural Networks (PINN). Supervised training presents some generalization issues since structures, and velocity ranges must be similar in training and test set. Some works integrated Full-waveform Inversion (FWI) with CNN, defining the problem of VMB in the PINN framework. In this case, the CNN stabilizes the inversion, acting like a regularizer and avoiding local minima-related problems and, in some cases, sparing an initial velocity model. Our approach combines supervised and physics-informed neural networks by using transfer learning to start the inversion. The pre-trained CNN is obtained using a supervised approach based on training with a reduced and simple data set to capture the main velocity trend at the initial FWI iterations. We show that transfer learning reduces the uncertainties of the process, accelerates model convergence, and improves the final scores of the iterative process.Comment: Paper present at machine Learning and the Physical Sciences workshop, NeurIPS 202

Development of a Questionnaire to Assess Knowledge and Perceptions about Edible Insects

Edible insects (EI) have been consumed as traditional foods in many parts of the globe, but in other regions, they are not readily accepted, particularly in Western countries. However, because EI are suggested to constitute a more sustainable protein food as compared with other sources of animal protein, they can be considered a future food that could help mitigate hunger and malnutrition. Additionally, new gastronomic trends are already targeting this area for exploring new potentialities. The objective of this work was to develop and validate a questionnaire to assess consumers’ perceptions and knowledge about EI in seven different domains: D1. Culture and Tradition, D2. Gastronomic Innovation and Gourmet Kitchen, D3. Environment and Sustainability, D4. Economic and Social Aspects, D5. Commercialization and Marketing, D6. Nutritional Aspects and D7. Health Effects. The 64 items were subjected to item analysis and reliability analysis for validation, and factor analysis was also conducted to identify a grouping structure. The results validated all the items of the seven subscales with high values of Cronbach’s alpha (α = 0.732 for D1, α = 0.795 for D2, α = 0.882 for D3, α = 0.742 for D4, α = 0.675 for D5, α = 0.799 for D6 and α = 0.788 for D7). However, by eliminating 17 items, the final values of the alpha increased in all subscales. Factor analysis with extraction by principal component analysis with varimax rotation extracted 14 factors that explained, in total, 65% of the variance, although the first two factors were the most important (35.7% variance explained). In conclusion, the confirmed usefulness of the questionnaire has been hereby validated for assessing consumer perceptions of and knowledge about EI.info:eu-repo/semantics/publishedVersio

Weighted Least Squares Techniques for Improved Received Signal Strength Based Localization

The practical deployment of wireless positioning systems requires minimizing the calibration procedures while improving the location estimation accuracy. Received Signal Strength localization techniques using propagation channel models are the simplest alternative, but they are usually designed under the assumption that the radio propagation model is to be perfectly characterized a priori. In practice, this assumption does not hold and the localization results are affected by the inaccuracies of the theoretical, roughly calibrated or just imperfect channel models used to compute location. In this paper, we propose the use of weighted multilateration techniques to gain robustness with respect to these inaccuracies, reducing the dependency of having an optimal channel model. In particular, we propose two weighted least squares techniques based on the standard hyperbolic and circular positioning algorithms that specifically consider the accuracies of the different measurements to obtain a better estimation of the position. These techniques are compared to the standard hyperbolic and circular positioning techniques through both numerical simulations and an exhaustive set of real experiments on different types of wireless networks (a wireless sensor network, a WiFi network and a Bluetooth network). The algorithms not only produce better localization results with a very limited overhead in terms of computational cost but also achieve a greater robustness to inaccuracies in channel modeling

Lixo registrado em áreas livres de gelo em uma Área Antártica Especialmente Gerenciada (AAEG): Baía do Almirantado, ilha Rei George, Península Antártica

The Protocol on Environmental Protection to the Antarctic Treaty, or Madri Protocol - 1991, was created with the objective of preventing the contamination of the Antarctic environment and to guarantee the preservation of its natural resources. From the past to the presented time the Antarctic is considered a special area for conservation because it has exclusive environmental characteristics. Admiralty Bay, located on King George Island (South Shetland), is an Antarctic Specially Managed Area (ASMA) and, at the moment, there are five international stations located there. Since the beginning of its human occupation in 1819, with the arrival of the first sailors a lot of environmental changes can be register. This paper makes the first register of debris in this area, based on studies carried out during the summers of 2002/2003, 2003/2004 and 2004/2005. In total, 186 items were recorded as debris. In our study the majority of the debris was composed of wood (49%), followed by synthetic materials: metal (18%), plastic (16%), miscellaneous (16%) and cement (1%). However, what we can observe is that most of the recorded debris for Admiralty Bay comes from research activities (38%), resulting from remaining construction debris of research support; or equally, abandoned experiments, whose structures were not removed. Key words: South Shetland Island, Admiralty Bay, waste, pollution, environmental impact.O Protocolo sobre Proteção Ambiental do Tratado Antártico, ou Protocolo de Madri, foi criado com o objetivo de prevenir a contaminação do meio ambiente antártico e garantir a preservação dos seus recursos naturais. Desde o passado e ainda no presente, a Antártica é considerada uma área especial para a conservação devido às suas características ambientais únicas. A Baía do Almirantado, localizada na ilha Rei George (Shetland do Sul), é uma Área Antártica Especialmente Gerenciada (AAEG) e, até o presente, tem cinco estações científicas internacionais localizadas na região. Desde o início da ocupação humana em 1819, com a chegada dos primeiros caçadores de baleias, muitas alterações ambientais vêm sendo registradas. Este artigo faz o primeiro registro do lixo encontrado nesta área, baseado em estudos desenvolvidos durante os verões de 2002/2003, 2003/2004 e 2004/2005. No total, 186 itens foram registrados como lixo encontrado na área. A maioria do lixo encontrado foi composta por madeira (49%), seguida por materiais sintéticos: metal (18%), plástico (16%), material variado (16%) e cimento (1%). Foi constatado que a maior parte do lixo registrado em nosso estudo na Baía do Almirantado resulta de atividades científicas, sendo composto de restos de construções para suporte à pesquisa e também oriundos de experimentos científicos abandonados, nos quais a estrutura não foi removida após o fim do experimento. Palavras-chave: ilhas Shetland do Sul, Baía do Almirantado, lixo, poluição, impacto ambiental