A new approach to spatial compression of stereoscopic videos

This paper presents a new spatial compression method specifically designed for stereo videos. Different form current compressors, which simply apply known 2D compression techniques, the method proposed here was developed taking into account specificities of the components of the spatial compression process which may impact the correct depth visualization, named Chrominance Subsampling, Discrete WaveletTransform (DWT) and Quantization. Each component was evaluated analyzing where datalosses occur and proposing ways to provide a good balance between compression ratio and image quality, minimizing losses in depth perception. The evaluations were made using standard objective (PSNR) and subjective (DSCQS) metrics, applied to an anaglyphic stereoscopic video base. The results showedour method is competitive regarding compression rate and providessuperior image quality.     

Mechanical and dynamic mechanical analysis of hybrid composites molded by resin transfer molding

This work aims to evaluate the performance of glass/sisal hybrid composites focusing on mechanical (flexural and impact) and dynamic mechanical analyses (DMTA). Hybrid composites with different fiber loadings and different volume ratios between glass and sisal were studied. The effect of the fiber length has also been investigated. The densities of the composites were compared with the theoretical values, showing agreement with the rule of mixtures. The results obtained in the flexural and impact analysis revealed that, in general, the properties were always higher for higher overall reinforcement content. By DMTA, an increase in the storage and loss modulus was found, as well as a shift to higher values for higher glass loading and overall fiber volume. It was also noticed an increase in the efficiency of the filler and the calculated activation energy for the relaxation process in the glass transition region. The fiber length did not significantly change the results observed in all analyses carried out in this work. The calculated adhesion factor increased for higher glass loadings, meaning the equation may not be applied for the system studied and there are other factors, besides adhesion influencing energy dissipation of the composites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Modification of physical properties of thermoplastic polyurethane by incorporation of low‐molecular‐weight diurethanes

In this study, two diurethanes were synthesized and blended with thermoplastic polyurethane (TPU), and the effects of the incorporation of these diurethanes on the physical properties of the TPU were evaluated. The diurethanes were obtained reacting 4,4′‐diphenylmethane‐diisocyanate with 1‐butanol (Additive 1) or 1‐octanol (Additive 2). An increase in the amount of Additive 1 promoted a reduction in the rigid phase glass transition temperature (T_g), while an increase in the amount of Additive 2 caused an increase in the T_g of this phase. Processing of the TPU increased the hardness and elastic modulus and decreased the tensile stress at break. Addition of diurethanes did not promote significant changes in the hardness and stress‐strain behavior, compared with the processed TPU; however, increasing the additive content decreased the elongation and tensile stress at break. Scanning electron microscopy micrographs showed that incorporation of diurethanes into TPU led to migration of these additives. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

Devulcanization of ethylene‐propylene‐diene polymer residues by microwave—Influence of the presence of paraffinic oil

Vulcanized rubbers are materials commonly used in various industrial applications. In this study, scraps of ethylene‐propylene‐diene rubber (EPDM‐r) from the automotive industry were submitted to different microwave exposure times (2–5 min). Samples of recycled rubber with (as received) and without (after extraction) paraffinic oil were analyzed. The devulcanized EPDM‐r was characterized by gel content, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The gel content indicated that the presence of paraffin oil in EPDM‐r affects the devulcanization process. The DSC analysis showed significant changes in the glass transition temperature (Tg). The Tg values for EPDM‐r decreased with an increase in the microwave exposure time. Furthermore, the presence of a thermal phenomenon characteristic of uncured material was observed. Sample degradation was studied through TGA, and the values for the activation energy (E_a) of the degradation process were determined using the Flynn‐Wall‐Ozawa method. For conversions up to 0.10, the E_a values of the EPDM‐r samples without oil decreased with an increase in the microwave exposure time. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers     

Effects of the incorporation of low‐molecular‐weight diurethanes on thermal and rheological properties of thermoplastic polyurethane

In this study, two low‐molecular‐weight diurethanes were synthesized and blended with thermoplastic polyurethane (TPU). The effects of the incorporation on the thermal and rheological properties of TPU were evaluated. The diurethanes were obtained from the reaction of 4,4′‐diphenylmethane‐diisocyanate (MDI) with 1‐butanol (Additive 1) or 1‐octanol (Additive 2). Blending of the additives with TPU was carried out in a torque rheometer, and the blends obtained were analyzed by differential scanning calorimetry (DSC), torque rheometry, and capillary rheometry. The torque rheometry showed that an increase in the amount of both additives displaced the charging peaks to longer times and reduced the torque values after melting. The DSC analysis showed that the incorporation of the additives did not affect the glass transition temperature (T_g) of the flexible phase of TPU. However, an increase in the amount of Additive 1 led to a reduction in the T_g of the rigid phase, while increasing the amount of Additive 2 caused an increase in the T_g of this phase. Capillary rheometry results showed that blends with up to 2 wt % of additive led to intrinsic viscosity and melt‐flow stability values higher than those of processed TPU. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Dynamic mechanical, thermal, and morphological study of ABS/textile fiber composites

In this work, acrylonitrile–butadiene–styrene ABS terpolymer was mixed with acrylic fiber, cotton fiber, and waste textile fiber (WTF) (50/50 wt% cotton/acrylic fiber) with 10 and 30 wt% of fiber content in a batch mixer. The composites with 30 wt% of acrylic fiber showed the highest stabilized torque, while the compositions with 30 wt% of cotton were situated at the lowest values in torque rheometry. The fiber addition up to 30 wt% did not have effect on the degradation behavior of ABS matrix. The composites with 30% textile fiber showed a higher degradation step, which is related to fiber degradation. The fiber content resulted in a considerable increase in stiffness at all temperatures as can be observed on the dynamic mechanical thermal properties (DMTA). The reinforcing effect was higher in the region above the glass transition temperature, T _g, of the matrix, this is primarily due to the larger difference in mechanical properties between the filler and the matrix as it goes from the glassy to the rubbery state.     

Evaluation of mechanical properties and physical interactions of a ternary blend of poly(ethylene‐co‐octene)/poly(ethylene‐co‐vinyl acetate)/poly(vinyl chloride) in the molten state

In this work, ethylene‐co‐vinyl acetate (EVA), poly(ethylene‐co‐octene) (POE), and poly(vinyl chloride) (PVC) blends were processed in a molten state process using a corotating twin‐screw extruder to assess both the balance of mechanical properties and physical interactions in the melt state. Tensile measurements, scanning electron microscopy, and oscillatory rheometry were performed. By means of flow curves, the parameters of the power law as well as the distribution of relaxation times were assessed with the aid of a nonlinear regularization method. The mechanical properties for the EVA‐POE blend approximated the values for POE, while inclusion of PVC shifted the modulus values to those of neat EVA. The rise in modulus was corroborated by the PVC phase dispersion as solid particles that act as a reinforcement for the ternary blend. The rheological properties in the molten state show that the POE does not present molecular entanglement effects and so tends both to diminish the EVA mechanical properties and increase the fluidity of the blend. However, the addition of PVC both restored the EVA typical pseudoplastic feature and promoted the increase in the viscosity and the mechanical properties of the ternary blend. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Clustering Search for the Berth Allocation Problem

This work presents a new approach to the Berth Allocation Problem (BAP) for ships in ports. Due to the increasing demand for ships carrying containers, the BAP can be considered as a major optimization problem in marine terminals. In this paper, the BAP is considered as dynamic and modeled in discrete case and we propose a new alternative to solve it. The proposed alternative is based on applying the Clustering Search (CS) method using the Simulated Annealing (SA) for solutions generation. The CS is an iterative method which divides the search space in clusters and it is composed of a metaheuristic for solutions generation, a grouping process and a local search heuristic. The computational results are compared against recent methods found in the literature.     

Structure and properties relationship of melt reacted polyamide 6/malenized soybean oil

In this work, a maleinized soybean oil (SOMA) was melt reacted with polyamide 6 and the thermal, rheological, and morphological properties were evaluated. It was observed that the maleinized soybean oil reacted with polyamide chains, increasing the molecular weight of the polymer. Addition of SOMA also promoted an increase in the amount of α crystalline phase as well as in the crystallinity index. The average amorphous layer thickness (L_a) was enhanced with the addition of 1 wt % of SOMA, while the average crystalline layer thickness (L_c) were significantly enlarged with the increase in SOMA content, indicating that SOMA structures were located at the interfacial region between amorphous and crystalline. The addition of 5 wt % of SOMA plasticized the PA6, reducing its glass transition temperature. However, the sample containing 5 wt % of SOMA showed an accentuated pseudoplastic behavior as compared to other samples. Addition of SOMA also reduced the tensile strength and increased the elongation at break. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43050.     

Degradation kinetics of vulcanized ethylene–propylene–diene terpolymer residues

In this study, ethylene–propylene–diene terpolymer residues (EPDM‐r) from the automotive industry were analyzed by thermogravimetric analysis (TGA) for determination of the activation energy (E_a) of decomposition by the Flynn‐Wall‐Ozawa (FWO) method. The degradation mechanism was determined by the method of Criado et al. Analysis of the nonvulcanized EPDM gum (EPDM‐g) and paraffinic oil used in the composition of the compound was also carried out. The E_a values for the decomposition of the EPDM‐g and paraffinic oil remained constant with the conversion, but for the EPDM‐r decomposition, they changed due to the initial oil elimination followed by decomposition of the EPDM fraction. It was observed that removal of the paraffinic oil occurred less easily in the tridimensional vulcanized network, and there were differences in the elimination mechanism. The EPDM degradation mechanism was also affected by vulcanization and the fillers present in the compound. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011