4,247 research outputs found
Datasets for Portuguese Legal Semantic Textual Similarity: Comparing weak supervision and an annotation process approaches
The Brazilian judiciary has a large workload, resulting in a long time to
finish legal proceedings. Brazilian National Council of Justice has established
in Resolution 469/2022 formal guidance for document and process digitalization
opening up the possibility of using automatic techniques to help with everyday
tasks in the legal field, particularly in a large number of texts yielded on
the routine of law procedures. Notably, Artificial Intelligence (AI) techniques
allow for processing and extracting useful information from textual data,
potentially speeding up the process. However, datasets from the legal domain
required by several AI techniques are scarce and difficult to obtain as they
need labels from experts. To address this challenge, this article contributes
with four datasets from the legal domain, two with documents and metadata but
unlabeled, and another two labeled with a heuristic aiming at its use in
textual semantic similarity tasks. Also, to evaluate the effectiveness of the
proposed heuristic label process, this article presents a small ground truth
dataset generated from domain expert annotations. The analysis of ground truth
labels highlights that semantic analysis of domain text can be challenging even
for domain experts. Also, the comparison between ground truth and heuristic
labels shows that heuristic labels are useful
Realistic fluids as source for dynamically accreting black holes in a cosmological background
We show that a single imperfect fluid can be used as a source to obtain the
generalized McVittie metric as an exact solution to Einstein's equations. The
mass parameter in this metric varies with time thanks to a mechanism based on
the presence of a temperature gradient. This fully dynamical solution is
interpreted as an accreting black hole in an expanding universe if the metric
asymptotes to Schwarzschild-de Sitter at temporal infinity. We present a simple
but instructive example for the mass function and briefly discuss the structure
of the apparent horizons and the past singularity.Comment: 5 pages, 2 figures. Updated references and minor changes to match the
version accepted for publishing in PR
Tipos de tecnologias de turbinas utilizadas nas centrais mini-hidricas
De todos os elementos que constituem uma central minihídrica
as turbinas e os geradores são os que mais dizem
respeito à engenharia electrotécnica. Este artigo pretende
apresentar os tipos de turbinas utilizadas nas centrais minihídricas.
Estas podem ser classificadas por duas tecnologias
distintas: turbinas de acção ou turbinas de reacção. As
turbinas de acção podem ser do tipo Pelton ou Banki-
Mitchell. As turbinas de reacção podem ser do tipo
Francis, Kaplan ou Hélice
Development and characterization of an environmentallyfriendly process sequence (autohydrolysis and organosolv) for wheat straw delignification
The present work describes the delignification of wheat straw through an environmentally friendly process resulting from sequential application of autohydrolysis and organosolv processes. Wheat straw autohydrolysis was performed at 180°C during 30 min with a liquid–solid ratio of 10 (v/w); under these conditions, a solubilization of 44% of the original xylan, with 78% of sugars as xylooligosaccharides of the sum of sugars solubilized in the autohydrolysis liquors generated by the hemicellulose fraction hydrolysis. The corresponding solid fraction enrichment with 63.7% of glucan and 7.55% of residual xylan was treated with a 40% ethanol and 0.1% NaOH aqueous solution at a liquid–solid ratio of 10 (v/w), with the best results obtained at 180°C during 20 min. The highest lignin recovery, measured by acid precipitation of the extracted lignin, was 3.25 g/100 ml. The lignin obtained by precipitation was characterized by FTIR, and the crystallinity indexes from the native cellulose, the cellulose recovered after autohydrolysis, and the cellulose obtained after applying the organosolv process were obtained by X-ray diffraction, returning values of 21.32%, 55.17%, and 53.59%, respectively. Visualization of the fibers was done for all the processing steps using scanning electron microscopy.The authors thank Professor Juan Carlos Parajo from University of Vigo, for the assistance in the materials preparation under autohydrolysis process as well as the ALBAN program for the PhD fellowship support
Water requirement and yield of fig trees under different drip irrigation management.
This work aimed to study the effect of drip irrigation management on growth and yield of the 'Roxo de Valinhos' fig tree (Ficus carica L.), at three years old, and to determine crop coefficients (Kc) and its water requirement (ETc) under Baixada Fluminense climate and soil conditions, state of Rio de Janeiro, Brazil. The study was carried out in the experimental area of SIPA (Sistema Integrado de Produção Agroecológica) in Seropédica, Rio de Janeiro State, from July 2011 to May 2012. The experimental area was divided in two blocks, named B1 (sandy clay loam texture) and B2 (loamy sand texture). In each block, irrigation frequencies (IF) of two (T1) and four days (T2) were evaluated, as well as the irrigation absence (T3). Irrigation management and water consumption determination were performed through the soil water balance, using the TDR technique. Plant growth was not affected by IF, differing only in the number of produced internodes. For both soil textures, the mean Kc was 0.60, with a significant difference (p<0.05) only for IF. The estimated mean yield showed no significant differences between both textural classes, ranging from 6,612 kg ha-1 (T3) to 8,554 kg ha-1 (T1). This study indicates the importance of irrigation frequency in the irrigation management of fig trees cultivated in soils with different physical characteristics
Studies of lignin and polysaccharides recovery from kraft liquor for biotechnological applications
According to the biorefinery concept, this study has the objective of evaluating alternatives for
the valorization of all the kraft liquor fractions. This liquor consists mainly in lignin, cellulose and
hemicellulose. Currently, cellulose pulp industries recover the cooking chemicals by burning and
energy is introduced into the process. Sustainable development guidelines, regarding the costs
and wastes reduction and biotechnology principles may present new solutions for the production
of valuable products.
In this study, two methods for the polysaccharides extraction, in three different pH conditions,
are presented. The only difference between these methods is the solvent applied: ethanol and
1,4‐dioxane. All the samples were maintained 24 h at 298 K. After a filtration step, the solid
fraction resultant from the ethanol treatment had a carbohydrate content of 40.51%, 44.64% and
49.53%, for pH values of 3, 4 and 6, respectively. The treatment with 1,4‐dioxane, reached the
following values: 21.17%, 18.41% and 29.73% for the same pH values. These results were
obtained with HPLC analysis after polysaccharides hydrolysis. Three unknown peaks were
detected that we considered to be sugar derivative compounds. Thus, the polysaccharides
contents, for both treatments, might actually be superior.
Concerning to the product purity, the ethanol extraction revealed to be the less efficient. The
lignin content in the solid fraction, ranged between 28% and 31%, with 1,4‐dioxane extraction,
and between 40% and 50%, with ethanol.
The lignin molecular weight was determined with GPC, after and before liquor pH lowering.
Thereby, for pH 6, pH 4 and pH 3 the obtained MWs were: 2376 Da, 1477 Da and 3705 Da,
respectively. The molecular weight increase may be due to the lignin repolymerization. These
results suggest that the polysaccharides recovery and lignin molecular weight may be related. As
the molecular weight increases or decreases, the polysaccharides percentage presents the same
behavior, regardless of the product purity. The data obtained after FT‐IR analysis suggested that
there was no significant modifications on lignin structure.
Summarizing, these preliminary results indicate that there is a possibility of recovering the kraft
liquor´s polysaccharide while the residual lignin can still be used for burning to energy recovery.Erasmus Mundus ‐ ISAC ProgramFundação para a Ciência e a Tecnologia (FCT)Millipore BrazilConselho Nacional de Desenvolvimento Científico e Tecnológico Brazil - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CNPq‐CAPES
Simple implementation of complex functionals: scaled selfconsistency
We explore and compare three approximate schemes allowing simple
implementation of complex density functionals by making use of selfconsistent
implementation of simpler functionals: (i) post-LDA evaluation of complex
functionals at the LDA densities (or those of other simple functionals); (ii)
application of a global scaling factor to the potential of the simple
functional; and (iii) application of a local scaling factor to that potential.
Option (i) is a common choice in density-functional calculations. Option (ii)
was recently proposed by Cafiero and Gonzalez. We here put their proposal on a
more rigorous basis, by deriving it, and explaining why it works, directly from
the theorems of density-functional theory. Option (iii) is proposed here for
the first time. We provide detailed comparisons of the three approaches among
each other and with fully selfconsistent implementations for Hartree,
local-density, generalized-gradient, self-interaction corrected, and
meta-generalized-gradient approximations, for atoms, ions, quantum wells and
model Hamiltonians. Scaled approaches turn out to be, on average, better than
post-approaches, and unlike these also provide corrections to eigenvalues and
orbitals. Scaled selfconsistency thus opens the possibility of efficient and
reliable implementation of density functionals of hitherto unprecedented
complexity.Comment: 12 pages, 1 figur
Produção de alimentos em sistemas agroflorestais de base agroecológica no cerrado na Região Sul de Mato Grosso do Sul.
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