Occlusions and binocular stereo

Binocular stereo is the process of obtaining depth information from a pair of cameras. In the past, stereo algorithms have had problems at occlusions and have tended to fail there (though sometimes post-processing has been added to mitigate the worst effects). We show that, on the contrary, occlusions can help stereo computation by providing cues for depth discontinuities.We describe a theory for stereo based on the Bayesian approach, using adaptive windows and a prior weak smoothness constraint, which incorporates occlusion. Our model assumes that a disparity discontinuity, along the epipolar line, in one eyealways corresponds to an occluded region in the other eye thus, leading to anocclusion constraint. This constraint restricts the space of possible disparity values, thereby simplifying the computations. An estimation of the disparity at occluded features is also discussed in light of psychophysical experiments. Using dynamic programming we can find the optimal solution to our system and the experimental results are good and support the assumptions made by the model.     

Sealing system activated by magnetic induction polymerization

This work describes the one‐step production of glycerin based polyurethane/magnetite nanocomposites. The polymerization was performed in a nonaqueous dispersion containing the magnetic nanoparticles and the polar monomers under alternating magnetic field. Fourier transform infrared spectroscopy and crosslink degree tests were useful to conclude that the use of magnetic induction (～3 min at 9300 W) produced results similar to the ones obtained by the conventional polymerization (～3 h at 80 °C) in a fraction of the required time. A lost circulation fluid control test also was performed under magnetic induction heating and the system containing 5 wt % of the nanoparticles showed the highest reduction of the fluid flow rate. Scanning electron microscopy and probability density function tests of the best material allowed inferring that composite prepared by magnetic induction presents a non‐Gaussian distribution of the diameter, which is directly related to the observed sealing effect. These results showed that proposed polymer/polymerization system can be very useful to the sealing applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45549.     

Low-Dimensional Confining Structures on the Surface of Helium Films Suspended on Designed Cavities

We investigate the formation of quantum confined structures on the surface of a liquid helium film suspended on a nanostructured substrate. We show theoretically that, by nanostructuring the substrate, it is possible to change the geometry of the liquid helium surface, opening the possibility of designing and controlling the formation of valleys with different shapes. By applying an external electric field perpendicular to the substrate plane, surface electrons can be trapped into these valleys, as in a quantum dot. We investigate how the external parameters, such as the electric field strength and the height of the liquid helium bath, can be tuned to control the energy spectrum of the trapped surface electrons.     

Three‐Step One‐Pot Synthesis of Imidazo[2,1‐b]chalcogenazoles via Intramolecular Cyclization of N‐Alkynylimidazoles

Imidazo‐chalcogenazoles are easily accessible from the corresponding N‐alkynylimidazoles by a three‐step, one‐pot chalcogenation reaction. The generality of this reaction has been established with various substituted N‐alkynylimidazoles as well as elemental chalcogens. By accessing the key intermediate 2‐chalcogenolate‐N‐alkynylimidazole it was also possible to prepare dichalcogenide derivatives.     

Dried Tomato‐Flavored Probiotic Cream Cheese with Lactobacillus paracasei

Abstract: A dried tomato‐flavored probiotic cream cheese (P) containing Lactobacillus paracasei Lpc‐37 was developed for the purpose of this study. The same product, but without probiotic addition (C) was used as control. Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris were used as lactic starter cultures. Chemical composition analyses and sensory tests were performed on days 1 and 7, respectively. Titratable acidity, pH value and L. paracasei population were determined every 7 d during the refrigerated storage (21 d) of the cream cheeses. The experiment and analyses were performed in triplicate, using standard methods. Probiotic population remained greater than 10⁷ CFU/g throughout the storage period, thereby characterizing the product as potentially probiotic. Cream cheeses C and P did not differ on the sensory tests, both obtaining good overall acceptance by the consumers, of which 82.6% stated that they certainly or probably would buy the product. Practical Application: Lactobacillus paracasei Lpc‐37 is a probiotic bacterium and clinical studies have shown that this microorganism beneficially affects its host. In general, dried tomato‐flavored products and cream cheese are products with good acceptance by the consumers. Thus, regular consumption of the probiotic cream cheese developed in this study may have positive effects on health and well being of people if incorporated into their diet.     

豆奶甲醇提取物中抗氧化活性物质的鉴定

本文主要在研究了豆奶甲醇提取物有无抗氧化活性的基础上,分析鉴定了其可能存在的抗氧化物质,为相关研究提供理论依据。测定抗氧化能力的方法包括1,1-二苯基-2-三硝基苯肼(1,1-Diphenyl-2-picrylhydrazyl radical, DPPH)法和铁离子还原能力(Ferric reducing antioxidant power ,FRAP)法。比色法测定总酚含量和总黄酮含量。通过超高效液相-四极杆飞行时间串联质谱(Ultra-high performance liquid chromatography-quadruple time-of-flight-mass spectrometry, UHPLC- QTOF-MS)测定豆奶甲醇提取液中活性成分的种类和含量。实验表明,豆奶甲醇提取液具有一定的抗氧化性,且DPPH法和FRAP 法测定豆奶抗氧化值不存在显著性差异。豆奶甲醇提取物的总酚含量(285.77±2.93 μg/mL)远高于总黄酮含量(11.27±0.51 μg/mL)。鉴定出5种化合物,其中只有6,7,4'-三羟基黄酮和Rha-Ara-GlcA-SoyB与抗氧化值存在正相关性。异黄素和大豆甙元两种异黄酮与抗氧化值存在着负相关,6,7,4'-三羟基黄酮可能是主要的抗氧化物质。     

Hard turning in continuous and interrupted cut with PCBN and whisker-reinforced cutting tools

PCBN (polycrystalline cubic boron nitride) is the most widely used material for tools employed in hardened steel turning applications due to its high hardness, wear resistance and thermal stability. However, its high costs severely limit its use. Alumina-based ceramics reinforced with whiskers, an alternative and less expensive material for these tools, has been used successfully in turning interrupted surfaces. The objective of this work is to investigate the conditions under which PCBN and ceramic tools can promote optimal results in the turning of hardened steel with continuous and interrupted surfaces. These tools were used in the radial turning of hardened steel with three types of surfaces: continuous surfaces and surfaces with 4 and 8 interruptions. The results indicated that, in continuous turning, the longest tool life was achieved using PCBN, but similar tool longevity was attained in interrupted turning using both PCBN and ceramic. In terms of roughness, the PCBN tools showed better results for continuous and interrupted surfaces.     

Statistical morphology and Bayesian reconstruction

The aim of this paper is to show that basic morphological operations can be incorporated within a statistical physics formulation as a limit when the temperature of the system tends to zero. These operations can then be expressed in terms of finding minimum-variance estimators of probability distributions. It enables us to relate these operations to alternative Bayesian or Markovian approaches to image analysis.We first show how to derive elementary dilations (winner-take-all) and erosions (loser-take-all). These operations, referred to as statistical dilations and erosion, depend on a temperature parameter =1/T. They become purely morphological as goes to infinity and become purely linear averages as goes to zero. Experimental results are given for a range of intermediate values of . Concatenations of elementary operations can be naturally expressed by stringing together conditional probability distributions, each corresponding to the original operations, thus yielding statistical openings and closings. Techniques are given for computing the minimum-variance estimators. Finally, we describe simulations comparing statistical morphology and Bayesian methods for image smoothing, edge detection, and noise reduction.     

Polystyrene recycling processes by dissolution in ethyl acetate

This study evaluated the thermal, morphological, chemical, and mechanical properties of virgin and recycled polystyrene. The recycling process was carried out by dissolution of polystyrene (extruded and crystal) in ethyl acetate, followed by two processes for solvent removal: vaporization by direct contact with water at 85 °C in a tubular evaporator and vaporization during the extrusion process. For the samples produced by solvent evaporation in the tubular evaporator, there was practically no degradation on polymer chain, neither reduction in glass transition temperature. For the samples produced by solvent evaporation during the extrusion, a polymer chain degradation was noted by reduction in molar weight and in glass transition temperature. The FTIR evaluation suggests that polymer oxidative degradation, in both samples, was more pronounced in the extruded sample. The removal of plasticizing additives could be evidenced by the glass transition temperature increase in the recycled samples produced in the tubular evaporator. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46208.     

Barriers to the adoption of green operational practices at Brazilian companies: effects on green and operational performance

The objective of this paper is to verify to what degree the internal and external barriers (I/EBs) to environmental management affect the adoption of green operational practices (GOPs) and to determine whether they influence the firms’ operational and green performance in a sample of Brazilian companies. A conceptual framework with 8 hypotheses is proposed and tested at 75 companies using Partial Least Squares-Structural Equation Modeling (PLS-SEM) with WarpPLS 4.0. The main results show that (a) the proposed framework obtained an adequate statistical adjustment, (b) the internal barriers (IBs) are more significant than the EBs when adopting GOPs, (c) GOPs relate directly to the firms’ green and operational performance (OP), (d) the IBs also indirectly influence the firms’ green and OP and (e) the firm size does not significantly influence its green and OP. This work contributes to the literature by showing that companies which are looking for green competitive advantages should try to reduce their IBs. Also, policy-makers should pay attention not only to legislation that promotes ecological modernisation, but also to create a strong set of initiatives to overcome IBs, regardless of the size of the firms.