Oxidation of methane to formaldehyde over Fe/SiO2 and Sn---W mixed oxides

In an attempt to develop new catalysts for the formation of formaldehyde from methane, the promotion effect of Fe on SiO₂ and that of Sn on WO₃ have been studied. The formation of formaldehyde on silica can be appreciably enhanced by the impregnation of Fe, as far as iron loadings are kept below 0.1 atom.% (Fe/Si × 100). In the case of Sn---W---Ox catalysts, both the addition of Sn to WO₃, and that of W on SnO₂ were effective to the selective formaldehyde formation. Absorption spectra (UV-Vis) and ESR measurements revealed that tetrahedrally coordinated Fe³⁺ in the silica network plays an important role in the formation of formaldehyde. A thin surface layer consisting of W and Sn oxides can account for the selective formaldehyde formation on the Sn---W---Ox catalysts.     

OA&M framework for multiwavelength photonic transport networks

Photonic networks based on wavelength division multiplexing (WDM) and optical path technologies are expected to realize flexible, transparent, and cost-effective transport networks with a large transmission capacity. This paper explores the design framework of photonic transport networks taking into consideration the operation administration and maintenance (OA&M) functions required for the successful introduction of WDM systems based on the optical path concept. From the view point of network maintenance, clear distinction is made between the optical path layer and the optical section layer to facilitate accurate and smooth failure localization. The digital multiplexing span between physical multiplexing interfaces at the end-to-end digital nodes should have the same maintenance span as the corresponding optical path. We argue that cooperative maintenance by OA&M functions at both the digital and optical layers can be a practical way of network supervision. A supervisory (SV) signal transfer method and a configuration that is suitable for the terrestrial trunk network are also indicated. As an example, a practical SV system design methodology and an actual procedure developed for a single channel optical transmission system based on optical in-line amplifiers are introduced. Furthermore, application of the developed SV system and network restoration schemes is discussed for future WDM-based photonic networks. The OA&M aspects introduced will be valuable for creating future photonic network systems     

Production of uniform droplets using membrane, microchannel and microfluidic emulsification devices

This review provides an overview of major microengineering emulsification techniques for production of monodispersed droplets. The main emphasis has been put on membrane emulsification using Shirasu Porous Glass and microsieve membrane, microchannel emulsification using grooved-type and straight-through microchannel plates, microfluidic junctions and flow focusing microfluidic devices. Microfabrication methods for production of planar and 3D poly(dimethylsiloxane) devices, glass capillary microfluidic devices and single-crystal silicon microchannel array devices have been described including soft lithography, glass capillary pulling and microforging, hot embossing, anisotropic wet etching and deep reactive ion etching. In addition, fabrication methods for SPG and microseive membranes have been outlined, such as spinodal decomposition, reactive ion etching and ultraviolet LIGA (Lithography, Electroplating, and Moulding) process. The most widespread application of micromachined emulsification devices is in the synthesis of monodispersed particles and vesicles, such as polymeric particles, microgels, solid lipid particles, Janus particles, and functional vesicles (liposomes, polymersomes and colloidosomes). Glass capillary microfluidic devices are very suitable for production of core/shell drops of controllable shell thickness and multiple emulsions containing a controlled number of inner droplets and/or inner droplets of two or more distinct phases. Microchannel emulsification is a very promising technique for production of monodispersed droplets with droplet throughputs of up to 100?l?h^?1.     

Polymerization via zwitterion 25. Alternating copolymerizations of cyclic acyl phosphorite and phosphite with vinyl monomers having an electron withdrawing group

Summary Spontaneous copolymerizations of cyclic acyl phosphonite (SPO) and phosphite (SPI) with an electron-deficient vinyl monomer such as methyl acrylate (MA), methyl vinyl ketone (MVK), and acrolein (AL), gave the corresponding alternating copolymers. These copolymerizations took place without added initiator and proceeded through zwitterion intermediates. Copolymer structures 1a, 1b, 2 and 3 have been established, all of which were derived in a regiospecific manner of ambident anions. The scheme of the copolymerizations is presented.     

Deposition of dense isotropic carbon from acetylene in fluidized bed

Pyrolytic carbon was deposited from acetylene in a fluidized bed at 1100°C on alumina microspheres. In case when only argon was used as the diluent gas, density and BAF of the deposit decreased and deposition yield increased with increasing acetylene concentration. Hydrogen sypply suppressed carbon formation and, consequently, caused an increase in density and Lc. BAF was relatively independent of hydrogen concentration. It was found that high density, isotropic carbon can be deposited from acetylene at 1100°C, if an appropriate proportion of hydrogen is added.     

A study on the factors for improving the ethanol production from Jerusalem artichoke by Kluyveromyces fragilis

This study is to investigate the factors influencing the alcohol production byKluyveromyces fragilis using the juice of Jerusalem Artichoke tubers. The cell growth rate and ethanol production rate were stimulated by aeration and by the addition of unsaturated fatty acids and the cell mass production and the ethanol production were substantially improved. It was found that oxygen and unsaturated fatty acids added played a decisive role on the increase of alcohol tolerance of yeast.     

Discussions of worker ants’ rule-based CHC dealing with changing environments

Contrary to popular belief, biologists discovered that worker ants are really not all hardworking. It has been found that in three separate 30-strong colonies of black Japanese ants (Myrmecina nipponica), about 20% of worker ants are diligent, 60% are ordinary, and 20% are lazy. That is called 20:60:20 rule. Though they are lazy, biologists suggested that lazy worker ants could be contributing something to the colony that is yet to be determined. In our last research, we used CHC (cross generational elitist selection, heterogeneous recombination, and cataclysmic mutation) with the worker ants’ rule (WACHC) aiming at solving optimization problems in changing environments. CHC is a nontraditional genetic algorithm (GA) which combines a conservative selection strategy that always preserves the best individuals found so far with a radical (highly disruptive) recombination operator. In our last research, we verified that WACHC performs better than CHC in only one case of fully changing environment. In this paper, we further discuss our proposed WACHC dealing with changing environment problems with varying degree of difficulty, compare our proposal with hypermutation GA which is also proposed for dealing with changing environment problems, and discuss the difference between our proposal and ant colony optimization algorithms.     

Performance comparison of tracking filters in terms of predicted hitting point

This article describes the performance comparison of several tracking filters from the viewpoint of gun fire control. It is common that filter performance can be represented by the RMSE of the current state. However, for the design of a gun fire control system, the performance of the tracking filter in terms of prediction is more important since the current state proceeds with a designed dynamic model to a certain future which is used for the final gun order. It is shown that the predicted results amplify the current state RMSE and can be a good measure.