Determination of photo-catalytic activity of un-doped and Mn-doped TiO2 anatase powders on acetaldehyde under UV and visible light

Titanium dioxide (TiO₂) photocatalytic powder materials doped with various levels of manganese (Mn) were synthesized to be used as additives to wall painting in combating indoor and outdoor air pollution. The heterogeneous photocatalytic degradation of gaseous acetaldehyde (CH₃CHO) on Mn-TiO₂ surfaces under ultraviolet and visible (UV/Vis) irradiation was investigated, by employing the Photochemical Static Reactor coupled with Fourier-Transformed Infrared spectroscopy (PSR/FTIR) technique. Experiments were performed by exposing acetaldehyde (~ 400 Pa) and synthetic air mixtures (~ 1.01 × 10⁵ Pa total pressure) on un-doped TiO₂ and doped with various levels of Mn (0.1-33% mole percentage) under UV and visible irradiation at room temperature. Photoactivation was initiated using either UV or visible light sources with known emission spectra. Initially, the photo-activity of CH₃CHO under the above light sources, and the physical adsorption of CH₃CHO on Mn-TiO₂ samples in the absence of light were determined prior to the photocatalytic experiments. The photocatalytic loss of CH₃CHO on un-doped TiO₂ and Mn-TiO₂ samples in the absence and presence of UV or visible irradiation was measured over a long time period (≈ 60 min), to evaluate their relative photocatalytic activity. The gaseous photocatalytic end products were also determined using absorption FTIR spectroscopy. Carbon dioxide (CO₂) was identified as the main photocatalysis product. It was found that 0.1% Mn-TiO₂ samples resulted in the highest photocatalytic loss of CH₃CHO under visible irradiation. This efficiency was drastically diminished at higher levels of Mn doping (1-33%). The CO₂ yields were the highest for 0.1% Mn-TiO₂ samples under UV irradiation, in agreement with the observed highest CH₃CHO decomposition rates. It was demonstrated that low-level (0.1%) doping of TiO₂ with Mn results in a significant increase of their photocatalytic activity in the visible range, compared to un-doped TiO₂. This elevated activity is lost at high doping levels (1-33%). Finally, the photocatalytic degradation mechanism of CH₃CHO on 0.1% Mn-TiO₂ surfaces under visible irradiation leading to low CO₂ yields is different than that under UV irradiation resulting to high CO₂ yields.     

Scratch behavior of extrusion and adhesive laminated multilayer food packaging films

Scratch‐induced puncture damages on adhesive and extrusion laminated multilayer food packaging films were investigated. Films were tested using a modified standardized linearly increasing load scratch test methodology, ASTM D7027‐05/ISO 19252:2008, which has successfully demonstrated an ability to correlate damages observed in field use of packaging films to laboratory findings. Samples were cross‐sectioned to view the evolution of damage in a layer‐by‐layer fashion to determine any potential weak‐link in the laminate. It was observed that the extrusion laminated film showed both superior scratch performance and superior layer adhesion with increasing scratch load, particularly upon severe film deformation. The extrusion lamination process may be used to produce strong, scratch‐resistant packaging films without the need for additional adhesive layers and the associated health and environmental concerns. Usefulness of the standardized scratch testing for evaluating performance of food packaging films and laminates is discussed. POLYM. ENG. SCI., 54:71–77, 2014. © 2013 Society of Plastics Engineers     

3-D quantitative vascular shape analysis for arterial bifurcations via dynamic tube fitting

Reliable and reproducible estimation of vessel centerlines and reference surfaces is an important step for the assessment of luminal lesions. Conventional methods are commonly developed for quantitative analysis of the "straight" vessel segments and have limitations in defining the precise location of the centerline and the reference lumen surface for both the main vessel and the side branches in the vicinity of bifurcations. To address this, we propose the estimation of the centerline and the reference surface through the registration of an elliptical cross-sectional tube to the desired constituent vessel in each major bifurcation of the arterial tree. The proposed method works directly on the mesh domain, thus alleviating the need for image upsampling, usually required in conventional volume domain approaches. We demonstrate the efficiency and accuracy of the method on both synthetic images and coronary CT angiograms. Experimental results show that the new method is capable of estimating vessel centerlines and reference surfaces with a high degree of agreement to those obtained through manual delineation. The centerline errors are reduced by an average of 62.3% in the regions of the bifurcations, when compared to the results of the initial solution obtained through the use of mesh contraction method.     

The Branching-Time Transformation Technique for Chain Datalog Programs

The branching-time transformation technique has proven to be an efficient approach for implementing functional programming languages. In this paper we demonstrate that such a technique can also be defined for logic programming languages. More specifically, we first introduce Branching Datalog, a language that can be considered as the basis for branching-temporal deductive databases. We then present a transformation algorithm from Chain Datalog programs to the class of unary Branching Datalog programs with at most one IDB atom in the body of each clause. In this way, we obtain a novel implementation approach for Chain Datalog, shedding at the same time new light on the power of branching-time logic programming.     

CO2 solubility in aqueous N-methylcyclohexylamine (MCA) and N-cyclohexyl-1,3-propanediamine (CHAP) solutions

N-methylcyclohexylamine (MCA) and N-cyclohexyl-1,3-propanediamine (CHAP) have been suggested, in mixtures with lipophilic amines, as potential phase change solvents for CO₂ capture applications, and subsequently studied as promising alternatives to monoethanolamine (MEA) for minimizing the desorber's energy requirements. In this study, new high pressure experimental data were obtained for the solubility of CO₂ in aqueous solutions containing MCA or CHAP at 313 and 333 K. The obtained data were used to parameterize the modified Kent–Eisenberg model. In this direction, CHAP was modeled assuming a “principle of independent reactivity,” that is, that the reactivity of each amine group does not depend on the potential reaction of the other one. It was shown that through this approach the model can be successfully applied to diamines using the relevant equations of amine mixtures.