Catalytic Total Oxidation of Methane. Part II. Catalytic Processes to Convert Methane: Partial or Total Oxidation

The introduction of solid catalysts into a traditionally non-catalytic free-radical process such as combustion occurred in recent years under the influence of environmental pressures. The major applications of catalytic combustion are two-fold: at low temperatures to eliminate volatile organic compounds (VOCs) and at high temperatures (>1000°C) to reduce NOx emission from gas turbines, jet motors, etc. It is the high temperature application that is reviewed here. Some recent developments in high-temperature catalytic combustion are trend setters in catalysis and hence of particular interest. For instance, novel materials are being developed for catalytic applications above 1000°C for sustained operation longer than one year. Where material/catalyst developments are still inadequate, systems engineering is coming to the rescue by developing multiple-monolith catalyst systems and the so-called hybrid (catalytic + thermal) reactors.     

The genuine short GRB 090227B and the disguised by excess GRB 090510

GRB 090227B and GRB 090510, traditionally classified as short gamma-ray Bursts (GRBs), indeed originate from different systems. For GRB 090227B we inferred a total energy of the e ⁺ e ^? plasma \(E_{e^ + e^ - }^{tot} \) = (2.83 ± 0.15) × 10⁵³ erg, a baryon load of B = (4.1 ± 0.05) × 10^?5, and a CircumBurstMedium (CBM) average density 〈n _CBM〉 = (1.90 ± 0.20) × 10^?5 cm^?3. From these results we have assumed the progenitor of this burst to be a symmetric neutron stars (NSs) merger with masses m = 1.34 M_⊙, radii R = 12.24 km. GRB 090510, instead, has \(E_{e^ + e^ - }^{tot} \) = (1.10 ± 0.06) × 10⁵³ erg, B = (1.45 ± 0.28) × 10^?3, implying a Lorentz factor at transparency of Γ = (6.7 ± 1.7) × 10², which are characteristic of the long GRB class, and a very high CBM density, 〈n _CBM〉 = (1.85 ± 0.14) × 10³ cm^?3. The joint effect of the high values of Γ and of 〈n _CBM〉 compresses in time and “inflates” in intensity in an extended afterglow, making appear GRB 090510 as a short burst, which we here define as “disguised short GRB by excess” occurring an overdense region with 10³ cm^?3.     

神奇玉米屋

这是Archi〈20的一个获奖项目。借助7000欧元的项目预算，这座占地20m^2的住宅原型修建在法国东北部慕泰索尔斯村上的自然保护区内。它遵循简单的创成式外形设计——即一个能够观察到四周景观的圆圈。     

Manifold surface reconstruction of an environment from sparse Structure-from-Motion data

The majority of methods for the automatic surface reconstruction of an environment from an image sequence have two steps: Structure-from-Motion and dense stereo. From the computational standpoint, it would be interesting to avoid dense stereo and to generate a surface directly from the sparse cloud of 3D points and their visibility information provided by Structure-from-Motion. The previous attempts to solve this problem are currently very limited: the surface is non-manifold or has zero genus, the experiments are done on small scenes or objects using a few dozens of images. Our solution does not have these limitations. Furthermore, we experiment with hand-held or helmet-held catadioptric cameras moving in a city and generate 3D models such that the camera trajectory can be longer than one kilometer.     

Statistical prioritization for software product line testing: an experience report

Software product lines (SPLs) are families of software systems sharing common assets and exhibiting variabilities specific to each product member of the family. Commonalities and variabilities are often represented as features organized in a feature model. Due to combinatorial explosion of the number of products induced by possible features combinations, exhaustive testing of SPLs is intractable. Therefore, sampling and prioritization techniques have been proposed to generate sorted lists of products based on coverage criteria or weights assigned to features. Solely based on the feature model, these techniques do not take into account behavioural usage of such products as a source of prioritization. In this paper, we assess the feasibility of integrating usage models into the testing process to derive statistical testing approaches for SPLs. Usage models are given as Markov chains, enabling prioritization of probable/rare behaviours. We used featured transition systems, compactly modelling variability and behaviour for SPLs, to determine which products are realizing prioritized behaviours. Statistical prioritization can achieve a significant reduction in the state space, and modelling efforts can be rewarded by better automation. In particular, we used MaTeLo, a statistical test cases generation suite developed at ALL4TEC. We assess feasibility criteria on two systems: Claroline, a configurable course management system, and Sferion?, an embedded system providing helicopter landing assistance.     

Fat crystal-stabilized water-in-oil emulsions as controlled release systems

Fat crystal-stabilized water-in-oil emulsions were developed as a controlled release matrix for the delivery of salt. Glycerol monostearate (GMS), glycerol monooleate (GMO) and polyglycerol polyricinoleate (PGPR) were used as emulsifiers and hydrogenated canola oil (HCO) was added as a solid fat. Salt release towards an external aqueous phase was measured via conductivity as a function of temperature. Following 2 h of release at room temperature, the GMS emulsion had the highest encapsulation efficiency followed by the PGPR-HCO, PGPR-only and GMO–HCO emulsions, respectively. The GMS crystals formed Pickering shells around the water droplets that effectively prevented salt transport whereas in the GMO–HCO emulsion, the presence of partial interfacial HCO crystal coverage resulted in lower retention. All crystal-stabilized emulsions showed rapid release of their salt load upon melting of the surrounding solid fat, while little temperature effect was observed with the PGPR-based emulsions. However, these emulsions were sensitive to the presence of a salt concentration gradient whereas the fat crystal-stabilized emulsions showed little response. Overall, this study demonstrated that the spatial distribution of the stabilizing fat crystals (i.e., interfacial vs. continuous phase) as well as the emulsifier type were critical factors controlling salt release patterns.     

Acknowledgement of Referees

The management of land resources, particularly the role of planning regulations, is critical in defining what land can be used in urban development – and this throws up certain key questions: How can one best manage land resources available? How can one address future urban development needs on the basis of existing land from a sustainable perspective? In this article we propose to question the extent of planning theories in the light of concrete urban development using land availability information. By using comprehensive national data we explore the case of Luxembourg, a small European country facing exacerbated pressures for metropolitanization. We use scenarios that go from a lesser to a greater degree of sustainability in order to project and articulate different configurations of land consumption based on a critical literature review (Smart Growth, New Urbanism, and transit oriented development (TOD)). We explore how modelling might be used to help inform spatial planning for urban growth. This framework is intended as an approach that would be applicable to other urban settings by using data that can be found in any typical municipal authority along with implementation in a geographical information system (GIS). The results create a tool which is useful for planning, monitoring or forecasting land consumption. The results also clearly show the limited impact of planning practices in terms of sustainability using land availability.     

Consolidation by spark plasma sintering of polyimide and polyetheretherketone

This article presents two high‐temperature thermoplastic powders which were sintered by spark plasma sintering in order to get homogeneous mechanical properties. Dense polyimide (PI) and polyetheretherketone (PEEK) specimens were obtained at temperatures as low as 320°C for PI and 200°C for PEEK, respectively. Relative densities higher than 99% were reached for both materials. In order to characterize their properties, in situ measurements with compression and hardness tests were carried out on sintered samples. This method allowed to obtain polymeric materials with improved mechanical properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40783.     

Experimental study of the stacking sequence effect on polymer/composite multi-layers submitted to thermomechanical cyclic loadings

Fast filling of hydrogen pressure tank leads to thermomechanical stresses in vessel structure. In this paper, the aim is to study the thermomechanical behaviour of the material used in the vessel structure. Flat coupons made of the same constituents as the hydrogen tank materials and with different stacking sequences have been tested under quasi-static tensile tests and fatigue. Three types of fatigue tests have been performed in order to understand damage mechanisms due to interactions between thermal and mechanical stresses: thermomechanical fatigue, 1 Hz mechanical fatigue and mechanical fatigue with a constant stress level stage. Damage development has been followed by acoustic emission and microscopic observations. Results show that, whatever the applied loading, there is a significant influence of the stacking sequence of the composite part. Moreover, the comparison of the material response to the different types of fatigue has revealed the harmful role of coupled temperature/mechanical cyclic stresses.