Manipulating refractive and reflective binocular disparity

Presenting stereoscopic content on 3D displays is a challenging task, usually requiring manual adjustments. A number of techniques have been developed to aid this process, but they account for binocular disparity of surfaces that are diffuse and opaque only. However, combinations of transparent as well as specular materials are common in the real and virtual worlds, and pose a significant problem. For example, excessive disparities can be created which cannot be fused by the observer. Also, multiple stereo interpretations become possible, e. g., for glass, that both reflects and refracts, which may confuse the observer and result in poor 3D experience. In this work, we propose an efficient method for analyzing and controlling disparities in computer‐generated images of such scenes where surface positions and a layer decomposition are available. Instead of assuming a single per‐pixel disparity value, we estimate all possibly perceived disparities at each image location. Based on this representation, we define an optimization to find the best per‐pixel camera parameters, assuring that all disparities can be easily fused by a human. A preliminary perceptual study indicates, that our approach combines comfortable viewing with realistic depiction of typical specular scenes.     

Kinetic correlations in codeposition of coatings of molybdenum-iron group metal alloys

Electrodeposition of Ni-Mo and Fe-Mo alloy coatings from acid citrate electrolyte was investigated over a wide range of cathode potentials and under various hydrodynamic conditions. Such alloys had been found to be deposited with substantial depolarization against iron group metals. With the same electrodeposition conditions, the molybdenum percentage in Fe-Mo coatings is much higher than in Ni-Mo. The molybdenum presence results in a lower overvoltage of hydrogen evolution, so that these alloys are deposited with a current efficiency much lower than that in the separate reduction of iron group metals. For a Ni-Mo system, the Mo percentage in the coating is increased together with increase of the transport rate of ions towards the cathode and with decrease of the cathode potential value being reduced; while for Fe-Mo alloy an inverse relation is observed. When passing from the Ni-Mo to the Fe-Mo system, the control of the molybdenum reduction reaction is changed. In codeposition with nickel it shows a diffusion control, while in discharging with iron its control is of the activation type. The Ni-Mo coatings obtained contained from 1.5–6% molybdenum whereas Fe-Mo deposits contained from 12–40% depending on electrolysis conditions. The quality of the coatings containing more than 20% Mo deteriorated and in these deposits some nonmetallic inclusions were present.     

Resistance to Coking Determination by Temperature Programmed Reaction of n-Butane with Steam

Resistance to coking is one of the most important characteristics of nickel catalysts used for steam reforming of hydrocarbons, CO₂ reforming or methanation of carbon oxides. Microbalance reactors have for a long time played an important role in catalyst deactivation studies, providing coking and coke gasification rates. However, conventional thermogravimetric microbalances have a number of limitations. The aim of this paper is to compare initial temperatures of coking of Ni and Ni-Mo catalysts (with different resistance to coking) obtained in the temperature-programmed reaction of _n-butane with steam with the results of coking rates obtained by the traditional thermogravimetric method. The investigations showed great agreement of the results.     

Spherulite nucleation in polypropylene blends with low density polyethylene

Primary nucleation of spherulites in blends of isotactic polypropylene (iPP) with low density polyethylene (LDPE) was investigated by means of differential scanning calorimetry and optical microscopy. The number of iPP spherulites in the blend decreases with increasing LDPE concentration to a much greater extent than follows from the decreasing amount of iPP. The shapes of spherulite size distributions indicate that athermal (heterogeneous) primary nucleation is inhibited. The density of primary nucleation in the blends decreases strongly with increasing mixing time. The same effect was observed in the blends with the nucleating agent which was added to iPP or LDPE. These experiments demonstrate that heterogenoeus nuclei migrate across interphase boundaries from the iPP melt to the LDPE melt during the mixing process. It is suggested that the interfacial energy difference between the nuclei and the molten components of the blend is responsible for the migration of nuclei.     

PdCl2(P(OPh)3)2 Catalyzed Coupling and Carbonylative Coupling of Phenylacetylenes with Aryl Iodides in Organic Solvents and in Ionic Liquids

Efficient cross-coupling and carbonylative coupling of terminal alkynes with aryl iodides catalyzed by PdCl₂(P(OPh)₃)₂ in the presence of NEt₃ in toluene and in ionic liquids is described. In imidazolium ionic liquids, [bmim]PF₆ or [mokt]PF₆ (bmim = 1-butyl-3-methyl imidazolium cation, mokt = 1-methyl-3-octyl imidazolium cation) catalyst was recycled and used in four concecutive catalytic cycles with high activity. In the absence of aryl iodide the same catalytic system catalyzed head-to-tail dimerization of phenylacetylene to the 1,3-diphenyl enyne, trans-PhC ≡ C–C(Ph)=CH₂, with a yield of 85%.     

Influence of progressive surface oxidation of nitrogen-containing carbon on its electrochemical behaviour in phosphate buffer solutions

The effects of the nitric acid surface oxidation of nitrogen-containing carbons (SCN-type) on the chemical structure as well as the electrochemical properties of powdered electrodes prepared from them were studied. The oxidation efficiency was dependent on the duration of the oxidative modification. The surface chemistry was characterized using standard neutralization techniques and spectroscopic methods (FTIR and XPS). Electrochemically active surface groups obtained on carbon materials during oxidation were investigated by cyclic voltammetry. Some noteworthy relations between the electrochemical activity of carbon electrode material and the degree of surface oxidation are reported.     

Thioether glycidyl resins. VII. Products of condensation of bis(4-mercaptophenyl)sulfide and bis(4-mercaptophenyl)sulfone with epichlorohydrin

New thioether glycidyl resins by condensation of bis(4-mercaptophenyl)sulfide or bis(4-mercaptophenyl)sulfone with epichlorohydrin were obtained by heterophase alkaline condensation in aqueous and isopropanol medium using sodium hydroxide. The detailed studies on their structures from elemental analysis and IR and ¹H-NMR spectra, physical and chemical properties, and curing conditions are presented. Thioether glycidyl resins compositions were also prepared using curatives typical for epoxy resins and after curing they were characterized from derivatographic, thermomechanical, and mechanical studies.     

Preparation of modified active carbon from brown coal by ammoxidation

The technology of obtaining active carbon enriched in nitrogen from brown coal is described. The effect of ammoxidation by a mixture of ammonia and air at the ratio 1:3 at 300 and 350 °C, at each stage of the active carbon production has been tested. The amount of nitrogen introduced into the active carbon has been proved to depend on the stage at which ammoxidation was performed. Carbonisation and activation with steam of the samples enriched in nitrogen have been found to lead to a significant decrease in its content and to cause an increase in the stability of the nitrogen groups. The ammoxidation of the active carbon has decreased their surface area, while the ammoxidation and high temperature of activation favour the formation of surface oxide groups of basic character.     

Application of diffusion dialysis for reduction of acidity of real pregnant leach solutions containing Ni and Co ions

ABSTRACT

Diffusion dialysis (DD) was proposed as a pretreatment step to reduce the acidity of real sulfate/chloride pregnant leach solutions containing cobalt(II) and nickel(II). Optimum DD conditions that enable reduction of acidity in the feed while maintaining a high rejection level of metal ions present in PLS were proposed, e.g. for 0.06 dm³/min flow of both aqueous phases H⁺ concentration in the dialysate reached 3.8 and 2.99 M for PLS1 and PLS2, respectively. Acid diffusion coefficients varied from 0.32 ?10 ^?6 to 3.15?10^?6 m/s and decreased with increasing phase flow rates. Moreover, dialysate neutralization was beneficial for the H⁺ reduction in the feed.