Lessons Learned from the Two Major Tailings Dam Accidents in Brazil

Mine Water and the Environment - The failures of the Mariana and Brumadinho tailings dams in Minas Gerais, Brazil, had severe environmental repercussions and caused many fatalities. What should or...     

Effects of porosity,dry unit weight,cement content and void/cement ratio on unconfined compressive strength of roof tile waste-silty soil mixtures

One of the conventional ways to improve the mechanical behavior of soils is to mix them with cementing agents such as cement, lime and fly ash. Recently, introduction to alternative materials or sub-products that can be adopted to improve the soil strength is of paramount importance. Therefore, the present study aims to investigate the effects of porosity (η), dry unit weight (γ_d) of molding, cement content (C) and porosity/volumetric cement content ratio (η/C_iv) or void/cement ratio on the unconfined compressive strength (q_u or UCS) of silty soil–roof tile waste (RT) mixtures. Soil samples are molded into four different dry unit weights (i.e. 13 kN/m³, 13.67 kN/m³, 14.33 kN/m³ and 15 kN/m³) using 3%, 6% and 9% cement and 5%, 15% and 30% RT. The results show that with the addition of cement, the strength of the RT–soil mixtures increases in a linear manner. On the other hand, the addition of RT decreases q_u of the samples at a constant percentage of cement, and the decrease in porosity can increase q_u. A dosage equation is derived from the experimental data using the porosity/volumetric cement content ratio (η/C_iv) where the control variables are the moisture content, crushed tile content, cement content and porosity.     

Effect of pine resin derivatives on the structural,thermal, and mechanical properties of Mater-Bi type bioplastic

The effect of three additives derived from pine resin, namely, gum rosin (GR) and two pentaerythritol ester of GR, Lurefor (LF) and Unik Tack (UT), in 5, 10, and 15 wt %, on the properties of Mater-Bi, based on plasticized starch, poly(butylene adipate-co-terephthalate), and poly(ε-caprolactone) (PCL), obtained by injection molding processes, was studied. The mechanical, microstructural, and thermal properties were evaluated. LF had a cohesive behavior with the components of Mater-Bi, increasing the toughness of the material up to 250% accompanied by an increase of tensile modulus and tensile strength. UT had an intermediate behavior, conferring cohesive and plasticizing effects, allowing an increase of 105% in impact resistance. GR had a more marked plasticizing effect. This allows processing temperatures of about 50 °C lower than those used for neat Mater-Bi. In addition, an increase of the elongation at break, toughness, and impact resistance in 370, 480, and 250%, respectively, was achieved. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48236.     

Analogue CMOS prototype vision chip with prewitt edge processing

In this study, the design and realization of an analogue CMOS prototype vision chip with Prewitt edge processing is presented. The chip is designed with voltage and current mode and the main parts are one 16?×?16 pixel array, one pair of absolute value circuits and two transimpedance amplifiers. The technology process is TSMC 0.35???m. The edge processing is performed parallely on pixel level. The performance of the sensor comprises a processing time of 450?ns; optical dynamic range of 53?dB; power consumption at 30 frames per second of 1.5?mW; peak signal to noise ratio of 44?dB.     

Stability of the FMR1 CGG repeat in a Basque sample

The fragile X syndrome is an X-chromosome-linked dominant disorder with reduced penetrance. It is the most common inherited form of mental retardation. The molecular basis is usually the unstable expansion of a CGG trinucleotide repeat in the 5' untranslated region of the first exon of the FMR1 gene, which resides at chromosome position Xq27.3 and is coincident with the cytogenetic fragile site FRAXA, which characterizes the syndrome. In the Biscay province of the Basque Country the prevalence of FRAXA in a mentally retarded sample of non-Basque origin is in the range of other analyzed Spanish populations. In the sample of Basque origin we have not found FRAXA site expression and the repeat size is in the normal range. Based on this, we have examined FMR1 gene stability in normal individuals of Basque origin from the Biscay province. This study is based on a sample of 242 X chromosomes. The results from the CGG repeat region of FMR1 indicate that a prevalence of predisposing normal alleles toward repeat instability in the Basque population is 0.00% or near to it. This could be 1 of the explanations of the apparently low fragile X syndrome incidence found in the Basque mentally retarded sample analyzed by us. This low incidence does not seem to be associated with the flanking microsatellite markers.     

Fisher’s decision tree

Univariate decision trees are classifiers currently used in many data mining applications. This classifier discovers partitions in the input space via hyperplanes that are orthogonal to the axes of attributes, producing a model that can be understood by human experts. One disadvantage of univariate decision trees is that they produce complex and inaccurate models when decision boundaries are not orthogonal to axes. In this paper we introduce the Fisher’s Tree, it is a classifier that takes advantage of dimensionality reduction of Fisher’s linear discriminant and uses the decomposition strategy of decision trees, to come up with an oblique decision tree. Our proposal generates an artificial attribute that is used to split the data in a recursive way.The Fisher’s decision tree induces oblique trees whose accuracy, size, number of leaves and training time are competitive with respect to other decision trees reported in the literature. We use more than ten public available data sets to demonstrate the effectiveness of our method.     

The ChaLearn gesture dataset (CGD 2011)

This paper describes the data used in the ChaLearn gesture challenges that took place in 2011/2012, whose results were discussed at the CVPR 2012 and ICPR 2012 conferences. The task can be described as: user-dependent, small vocabulary, fixed camera, one-shot-learning. The data include 54,000 hand and arm gestures recorded with an RGB-D \(\hbox {Kinect}^\mathrm{TM}\) camera. The data are organized into batches of 100 gestures pertaining to a small gesture vocabulary of 8–12 gestures, recorded by the same user. Short continuous sequences of 1–5 randomly selected gestures are recorded. We provide man-made annotations (temporal segmentation into individual gestures, alignment of RGB and depth images, and body part location) and a library of function to preprocess and automatically annotate data. We also provide a subset of batches in which the user’s horizontal position is randomly shifted or scaled. We report on the results of the challenge and distribute sample code to facilitate developing new solutions. The data, datacollection software and the gesture vocabularies are downloadable from http://gesture.chalearn.org. We set up a forum for researchers working on these data http://groups.google.com/group/gesturechallenge.     

Free amino acids and biogenic amines in Alicante Monastrell wines

The simultaneous determination of 17 free amino acids and 8 biogenic amines in Alicante Monastrell wines was investigated for the first time. The quantification was carried out by using a RP-HPLC method, based on a pre-column derivatization with o-phthaldialdehyde (OPA) and fluorescence detection. From the results obtained it may be concluded that the most abundant free amino acids were Glu, Arg, Ala Asp, and Lys. None of the wine samples analysed had histamine (HIM) or Tyramine (TYM) levels above the limits considered as a possible toxic risk for healthy individuals. No measurable amounts of cadaverine (CAD) or methylamine (MEA) were found, showing no spoilage symptoms of sensory properties of the wines. Tryptamine (TRM) content was significantly higher in aged wines compared to young wines. However ethanolamine (ETA) content was lower. These data were used to make a preliminary classification of the samples using cluster analysis.     

Formation of toxic 2-nonyl-p-benzoquinones from α-tertiary 4-nonylphenol isomers during microbial metabolism of technical nonylphenol

In many environmental compartments, microbial degradation of α-quaternary nonylphenols proceeds along an ipso-substitution pathway. It has been reported that technical nonylphenol contains, besides α-quaternary nonylphenols, minor amounts of various α-H, α-methyl substituted tertiary isomers. Here, we show that potentially toxic metabolites of such minor components are formed during ipso-degradation of technical nonylphenol by Sphingobium xenophagum Bayram, a strain isolated from activated sewage sludge. Small but significant amounts of nonylphenols were converted to the corresponding nonylhydroquinones, which in the presence of air oxygen oxidized to the corresponding nonyl-p-benzoquinones-yielding a complex mixture of potentially toxic metabolites. Through reduction with ascorbic acid and subsequent analysis by gas chromatography-mass spectrometry, we were able to characterize this unique metabolic fingerprint and to show that its components originated for the most part from α-tertiary nonylphenol isomers. Furthermore, our results indicate that the metabolites mixture also contained several α, β-dehydrogenated derivatives of nonyl-p-benzoquinones that originated by hydroxylation induced rearrangement, and subsequent ring and side chain oxidation from α-tertiary nonylphenol isomers. We predict that in nonylphenol polluted natural systems, in which microbial ipso-degradation is prominent, 2-alkylquinone metabolites will be produced and will contribute to the overall toxicity of the remaining material.